EVERY bird, living or extinct, that survived the K-T disaster is believed
to be descended from the last common ancestor of living birds.
However, there are some articles which hypothesize that there is one exception,
a group of [long extinct] birds called the lithornids.
The lithornids, about which I wrote in the preceding post to this thread,
got their name (literally, "stone birds") from the fact that the first one
to be described, *Lithornis,* was among the very first fossil birds
to be described in the scientific literature.
Owen described it in 1840, long before anyone had heard of Archaeopteryx.
He thought it was a vulture.
https://en.wikipedia.org/wiki/Lithornis
It wasn't until 1988 that Houde, with a well preserved skull of *Lithornis* to study,
found that it was palaeognathous. This put it very far from vultures, which are neognaths: there is a split right at the base of the tree of birds that survived the K-T disaster, with paleognaths on one side and neognaths
on the other, according to most paleontologists specializing in birds,
and most systematists, who use cladistic methods to study phylogeny.
The palaeognaths of today comprise all the flightless birds known as ratites, and the tinamous, which are capable of short flights.
The lithornids were also palaeognathous, but they were strong flyers
capable of covering big distances without alighting. The ratites and
the tinamous are both believed to be descended from them.
They thus account for the widely separated places where ratites
(ostrich, emu, cassowary, rhea, kiwi) are to be found. New Zealand
was never connected to the continents where the other ratites
are to be found. Its ratites included the moas along with the kiwis.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
Univ. of South Carolina in Columbia
http://people.math.sc.edu/nyikos
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaurs
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great
that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow.
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,
and why did others, including some similar-seeming ones, perish?
On 11/9/22 6:14 PM, Peter Nyikos wrote:
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaurs
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which
hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow.
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,What sort of data did the 2013 Science article use to come to its conclusions? Was later widespread acceptance of the conclusions of the article based upon generally sound evidence?
and why did others, including some similar-seeming ones, perish?
On Sunday, November 13, 2022 at 4:07:11 AM UTC-8, Trolidan7 wrote:
On 11/9/22 6:14 PM, Peter Nyikos wrote:
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaursWhat sort of data did the 2013 Science article use to come to its
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great >>> that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote
ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which
hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow.
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,
and why did others, including some similar-seeming ones, perish?
conclusions? Was later widespread acceptance of the conclusions of the
article based upon generally sound evidence?
More recent research in placental evolution is reviewed here:
"Evolutionary Models for the Diversification of Placental Mammals Across the KPg Boundary" (Springer et. al.)
https://www.frontiersin.org/articles/10.3389/fgene.2019.01241/full
The upshot is that "consensus on the tempo and mode of placental diversification remains elusive".
On 11/13/22 10:14 AM, erik simpson wrote:
On Sunday, November 13, 2022 at 4:07:11 AM UTC-8, Trolidan7 wrote:
On 11/9/22 6:14 PM, Peter Nyikos wrote:
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaursWhat sort of data did the 2013 Science article use to come to its
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great >>> that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote >>> ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which
hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow.
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,
and why did others, including some similar-seeming ones, perish?
conclusions? Was later widespread acceptance of the conclusions of the
article based upon generally sound evidence?
More recent research in placental evolution is reviewed here:
"Evolutionary Models for the Diversification of Placental Mammals Across the KPg Boundary" (Springer et. al.)
https://www.frontiersin.org/articles/10.3389/fgene.2019.01241/full
The upshot is that "consensus on the tempo and mode of placental diversification remains elusive".It is rather good that you can simply click on the link and get to
the article.
I have written down the Science 2013 article and see if I can
find it somewhere.
The articles that you have linked to seem to give the idea
that 'we don't know'. That seems quite likely but I will
see if I can find the Science article and see what it might
say.
I am thinking someone somewhere typed that 'penguins are
the best of birds'. I would tend to disagree, for if
there is something that could be called 'advanced' or
'not advanced' I tend to like the song birds or passerines
with their opposable toes for perching.
When looking up the Wikipedia article on the song birds,
however, it seemed to show some charts speculating that they
might have diverged after the KPg boundary, but gave
the idea that the ratites, land fowl, and water fowl
may have all diverged prior to that. I would
tend to think that if any of them diverged during the
Mesozoic that it would be the Paleognaths.
On 11/13/22 10:14 AM, erik simpson wrote:
On Sunday, November 13, 2022 at 4:07:11 AM UTC-8, Trolidan7 wrote:
On 11/9/22 6:14 PM, Peter Nyikos wrote:
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaursWhat sort of data did the 2013 Science article use to come to its
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great >>> that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote >>> ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which
hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow.
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,
and why did others, including some similar-seeming ones, perish?
conclusions? Was later widespread acceptance of the conclusions of the
article based upon generally sound evidence?
More recent research in placental evolution is reviewed here:
"Evolutionary Models for the Diversification of Placental Mammals Across the KPg Boundary" (Springer et. al.)
https://www.frontiersin.org/articles/10.3389/fgene.2019.01241/full
The upshot is that "consensus on the tempo and mode of placental diversification remains elusive".
It is rather good that you can simply click on the link and get to
the article.
I have written down the Science 2013 article and see if I can
find it somewhere.
The articles that you have linked to seem to give the idea
that 'we don't know'. That seems quite likely but I will
see if I can find the Science article and see what it might
say.
I am thinking someone somewhere typed that 'penguins are
the best of birds'.
I would tend to disagree, for if
there is something that could be called 'advanced' or
'not advanced' I tend to like the song birds or passerines
with their opposable toes for perching.
When looking up the Wikipedia article on the song birds,
however, it seemed to show some charts speculating that they
might have diverged after the KPg boundary, but gave
the idea that the ratites, land fowl, and water fowl
may have all diverged prior to that.
I would
tend to think that if any of them diverged during the
Mesozoic that it would be the Paleognaths.
Unfortunately, as I indicated above, time has marched on...
in the world of research.
On Tuesday, November 15, 2022 at 7:56:06 PM UTC-8, peter2...@gmail.com wrote:
...
Unfortunately, as I indicated above, time has marched on...
in the world of research.
This isn't TO (fortunately), but this would otherwise be a great Chez Watt.
On Wednesday, November 16, 2022 at 11:18:45 AM UTC-5, erik simpson wrote:
On Tuesday, November 15, 2022 at 7:56:06 PM UTC-8, peter2...@gmail.com wrote:Not sure why: what category do you envision?
...
Unfortunately, as I indicated above, time has marched on...
in the world of research.
This isn't TO (fortunately), but this would otherwise be a great Chez Watt.
Do keep in mind that a great Chez Watt does NOT rely on people knowing who uttered it.
Nor, *a fortiori*, does it bank on reputations of the utterer based on unsupported canards in
completely different contexts than the one specified with "as I indicated above."
Anyway, I haven't had the chance to fully catch up with the march of time myself :)Biological Sciences. 283 (1833): 20153026.
in that context, but I do have a lot of progress to report: I've found the article [1]
that seems to have rehabilitated the central thesis of the 2013 Science article,
that the crown group placentals had their LCA after the K-T disaster.
[1] Halliday, Thomas John Dixon; Upchurch, Paul; Goswami, Anjali (2016-06-29). "Eutherians experienced elevated evolutionary rates in the immediate aftermath of the Cretaceous–Palaeogene mass extinction". Proceedings of the Royal Society B:
https://discovery.ucl.ac.uk/id/eprint/1473028/1/Halliday_et_al-Biological_Reviews.pdf2418
The article you linked [2] has no specific criticism for this paper,
nor for a 2019 paper by Halliday et.al, [3] which supported the rehabilitation.
However, it does have some very general cautionary notes,
adding a more specific one from this same 2019 paper itself [4].
[2] "Evolutionary Models for the Diversification of Placental Mammals Across the KPg Boundary" (Springer et. al.)
https://www.frontiersin.org/articles/10.3389/fgene.2019.01241/full
[3] Halliday, T. J., dos Reis, M., Tamuri, A. U., Ferguson-Gow, H., Yang, Z., Goswami, A. (2019). Rapid morphological evolution in placental mammals post-dates the origin of the crown group. Proc. R. Soc. Lond. B 286, 20182418. doi: 10.1098/rspb.2018.
[4] "Finally, a recent study on morphological evolution in placental mammals concluded that it may be very difficult to distinguish early members of the major placental groups from stem eutherians on the basis of skeletal and dental characters becauseCretaceous forms were not ecologically diverse and may appear very similar to each other (Halliday et al., 2019)."
Temporary assessment: the post-K-T crown placental LCA hypothesis still seems
to be the favored one, but nothing like a confident consensus has emerged. Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of So. Carolina at Columbia
http://people.math.sc.edu/nyikos
On Wednesday, November 16, 2022 at 9:48:38 AM UTC-8, peter2...@gmail.com wrote:
On Wednesday, November 16, 2022 at 11:18:45 AM UTC-5, erik simpson wrote:
On Tuesday, November 15, 2022 at 7:56:06 PM UTC-8, peter2...@gmail.com wrote:Not sure why: what category do you envision?
...
Unfortunately, as I indicated above, time has marched on...
in the world of research.
This isn't TO (fortunately), but this would otherwise be a great Chez Watt.
Do keep in mind that a great Chez Watt does NOT rely on people knowing who uttered it.
Nor, *a fortiori*, does it bank on reputations of the utterer based on unsupported canards in
completely different contexts than the one specified with "as I indicated above."
Biological Sciences. 283 (1833): 20153026.Anyway, I haven't had the chance to fully catch up with the march of time myself :)
in that context, but I do have a lot of progress to report: I've found the article [1]
that seems to have rehabilitated the central thesis of the 2013 Science article,
that the crown group placentals had their LCA after the K-T disaster.
[1] Halliday, Thomas John Dixon; Upchurch, Paul; Goswami, Anjali (2016-06-29). "Eutherians experienced elevated evolutionary rates in the immediate aftermath of the Cretaceous–Palaeogene mass extinction". Proceedings of the Royal Society B:
2418https://discovery.ucl.ac.uk/id/eprint/1473028/1/Halliday_et_al-Biological_Reviews.pdf
The article you linked [2] has no specific criticism for this paper,
nor for a 2019 paper by Halliday et.al, [3] which supported the rehabilitation.
However, it does have some very general cautionary notes,
adding a more specific one from this same 2019 paper itself [4].
[2] "Evolutionary Models for the Diversification of Placental Mammals Across the KPg Boundary" (Springer et. al.)
https://www.frontiersin.org/articles/10.3389/fgene.2019.01241/full
[3] Halliday, T. J., dos Reis, M., Tamuri, A. U., Ferguson-Gow, H., Yang, Z., Goswami, A. (2019). Rapid morphological evolution in placental mammals post-dates the origin of the crown group. Proc. R. Soc. Lond. B 286, 20182418. doi: 10.1098/rspb.2018.
because Cretaceous forms were not ecologically diverse and may appear very similar to each other (Halliday et al., 2019)."[4] "Finally, a recent study on morphological evolution in placental mammals concluded that it may be very difficult to distinguish early members of the major placental groups from stem eutherians on the basis of skeletal and dental characters
Temporary assessment: the post-K-T crown placental LCA hypothesis still seems
to be the favored one, but nothing like a confident consensus has emerged. Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of So. Carolina at Columbia
http://people.math.sc.edu/nyikos
I don't believe you actually meant to say it's unfortunate that "time has marched on
in the world of research", but you did say it.
There's no direct connection to your reputation
intended.
Review papers are just that; summaries of recent work in some area of interest, primarily
intended for those interested, but not intimately involved.
Uncertainty is inevitable in periods
of rapid evolution, such as follow major extinction events.
Future discoveries may clarify some
aspects, or may not. Fossils are sometimes reluctant witnesses.
On Monday, November 14, 2022 at 2:13:48 PM UTC-5, Trolidan7 wrote:
On 11/13/22 10:14 AM, erik simpson wrote:
On Sunday, November 13, 2022 at 4:07:11 AM UTC-8, Trolidan7 wrote:
On 11/9/22 6:14 PM, Peter Nyikos wrote:
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaursWhat sort of data did the 2013 Science article use to come to its
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great >>>>> that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote >>>>> ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which
hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow.
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,
and why did others, including some similar-seeming ones, perish?
conclusions? Was later widespread acceptance of the conclusions of the >>>> article based upon generally sound evidence?
More recent research in placental evolution is reviewed here:
"Evolutionary Models for the Diversification of Placental Mammals Across the KPg Boundary" (Springer et. al.)
https://www.frontiersin.org/articles/10.3389/fgene.2019.01241/full
The upshot is that "consensus on the tempo and mode of placental diversification remains elusive".
It is rather good that you can simply click on the link and get to
the article.
I have written down the Science 2013 article and see if I can
find it somewhere.
Erik gave you a link that works. I call your attention especially to the very detailed
phylogenetic tree on page 663 (the second page of the article).
That article has a colorful history.
Almost immediately, some biologists, including at least one paleontologist, noted that Protungulatum, which appears on the tree just below the bats,
also had another species that appeared during the late Cretaceous.
This seemed to kill the central finding of the article, which claimed that the last common ancestor (LCA) of all living placentals appeared after
the K-T boundary, and hence after the Cretaceous.
However, a later and much more detailed phylogenetic analysis
showed Protungulatum as not descended from that LCA.
Unfortunately, I can't remember the title or the authors of
that later research article. My printout of that article was packed away
and I haven't found it yet. It did, however, appear before 2019,
so it probably is covered somewhere in the Frontiers in Science
article Erik linked for you [see above].
The articles that you have linked to seem to give the idea
that 'we don't know'. That seems quite likely but I will
see if I can find the Science article and see what it might
say.
Unfortunately, as I indicated above, time has marched on
in the world of research. The article Erik linked MIGHT
have the last word in the line of argument I gave above,
but the information in the article is so mashed together, I'm not sure
I can find it, what with not remembering the title of that later article.
Now you shifted from mammals to birds:
I am thinking someone somewhere typed that 'penguins are
the best of birds'.
Whatever that means.
I would tend to disagree, for if
there is something that could be called 'advanced' or
'not advanced' I tend to like the song birds or passerines
with their opposable toes for perching.
When looking up the Wikipedia article on the song birds,
however, it seemed to show some charts speculating that they
might have diverged after the KPg boundary, but gave
the idea that the ratites, land fowl, and water fowl
may have all diverged prior to that.
Harshman is of this opinion.
> I would
tend to think that if any of them diverged during the
Mesozoic that it would be the Paleognaths.
That does seem likely, but so far, no fossil paleognaths
have turned up.
Peter Nyikos
Professor, Dept. of Mathematics
Univ. of South Carolina -- standard disclaimer-- http://people.math.sc.edu/nyikos
On 11/15/22 7:56 PM, Peter Nyikos wrote:
On Monday, November 14, 2022 at 2:13:48 PM UTC-5, Trolidan7 wrote:
On 11/13/22 10:14 AM, erik simpson wrote:
On Sunday, November 13, 2022 at 4:07:11 AM UTC-8, Trolidan7 wrote:
On 11/9/22 6:14 PM, Peter Nyikos wrote:
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaursWhat sort of data did the 2013 Science article use to come to its
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great
that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote >>>>> ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which
hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow. >>>>>
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,
and why did others, including some similar-seeming ones, perish?
conclusions? Was later widespread acceptance of the conclusions of the >>>> article based upon generally sound evidence?
More recent research in placental evolution is reviewed here:
"Evolutionary Models for the Diversification of Placental Mammals Across the KPg Boundary" (Springer et. al.)
https://www.frontiersin.org/articles/10.3389/fgene.2019.01241/full
The upshot is that "consensus on the tempo and mode of placental diversification remains elusive".
It is rather good that you can simply click on the link and get to
the article.
I have written down the Science 2013 article and see if I can
find it somewhere.
Erik gave you a link that works. I call your attention especially to the very detailed
phylogenetic tree on page 663 (the second page of the article).
That article has a colorful history.
Almost immediately, some biologists, including at least one paleontologist,
noted that Protungulatum, which appears on the tree just below the bats, also had another species that appeared during the late Cretaceous.
This seemed to kill the central finding of the article, which claimed that the last common ancestor (LCA) of all living placentals appeared after
the K-T boundary, and hence after the Cretaceous.
However, a later and much more detailed phylogenetic analysis
showed Protungulatum as not descended from that LCA.
Unfortunately, I can't remember the title or the authors of
that later research article. My printout of that article was packed away and I haven't found it yet. It did, however, appear before 2019,
so it probably is covered somewhere in the Frontiers in Science
article Erik linked for you [see above].
When looking up the Wikipedia article on the song birds,
however, it seemed to show some charts speculating that they
might have diverged after the KPg boundary, but gave
the idea that the ratites, land fowl, and water fowl
may have all diverged prior to that.
Harshman is of this opinion.
I would
tend to think that if any of them diverged during the
Mesozoic that it would be the Paleognaths.
That does seem likely, but so far, no fossil paleognaths
have turned up.
It is amazing that you can come up with these articles
that I can click on and see by just posting these links.
At some point I am thinking I may want to tour some local
libraries, however some time again.
It would seem to me bad if it has been common in recent
times for libraries to throw out such material thinking
that internet forms are adequate, and then all the links
mutated into something that could no longer be found or
used because of paywalls or simply errors.
Thank you both for the links and references.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
On 11/10/22 17:20, Peter Nyikos wrote:
They thus account for the widely separated places where ratitesThe real question is how would they taste on Thanksgiving!
(ostrich, emu, cassowary, rhea, kiwi) are to be found. New Zealand
was never connected to the continents where the other ratites
are to be found. Its ratites included the moas along with the kiwis.
Good week one and all.
They thus account for the widely separated places where ratites
(ostrich, emu, cassowary, rhea, kiwi) are to be found. New Zealand
was never connected to the continents where the other ratites
are to be found. Its ratites included the moas along with the kiwis.
Emus aren't bad, but they don't taste like turkey.
On 11/20/22 11:36, erik simpson wrote:Here's hoping you aren't serious! Emu is actully sold in groceries and listed on
Emus aren't bad, but they don't taste like turkey.try roasted yellow canary in a puffery roll with a dab of powered sugar.
It does great with Irish Coffee at the fireplace before the main course
...
On 11/9/22 21:14, Peter Nyikos wrote:
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.short?
Frogs hopped right through.
On Wednesday, November 16, 2022 at 7:05:55 PM UTC-5, Trolidan7 wrote:
Thank you both for the links and references.Glad to be of help. I hope you keep following this thread,
because I have lots more to contribute to it.
Tomorrow, I will have a post on monotremes. Next week,
Monday, I'll have another on birds; then come marsupials.
On Thursday, November 17, 2022 at 9:10:34 PM UTC-5, Peter Nyikos wrote:
On Wednesday, November 16, 2022 at 7:05:55 PM UTC-5, Trolidan7 wrote:
Thank you both for the links and references.Glad to be of help. I hope you keep following this thread,
because I have lots more to contribute to it.
Tomorrow, I will have a post on monotremes. Next week,
Monday, I'll have another on birds; then come marsupials.
The best laid plans of mice and men...
I hope you haven't given up waiting. Here is the post on monotremes; then tomorrow,
unless my family has a very full schedule, comes the next one on birds.
Monotremes have a very sparse fossil record, but it goes back to the early Cretaceous,
over 100 mya, when there were at least three different genera: Steropodon, Kryoryctes, and Teinolophos.
Then, except for some disputed specimens, there is nothing until the only non-Australian
known monotreme, Monotrematum sudamericanum – 61 million years old, past the K-T
extinction event. Some classify it as a species of Obdurodon, otherwise known from
the early Miocene (24 mya) to the very late Miocene, 5 mya. If the identification
is correct, then Obdurodon was a "living fossil" by the time it became extinct.
Obdurodon was quite similar to the living platypus, except that it had some teeth
as an adult. The living platypus, Ornithorhynchus anatinus, only has milk teeth
and when those are shed, only the familiar bill remains.
If Monotrematum was actually an Obdurodon, then it is quite probable
that Obdurodon was a K-T survivor, the lone monotreme with that distinction.
A funny thing about all these monotremes: they all are believed
to be "duckbills" of some sort. The echidnas diverged from them
at some time and have obviously undergone some drastic changes in their mouth parts.
Peter Nyikos
Professor, Dept. of Mathematics
University of So. Carolina -- standard disclaimer-- http://people.math.sc.edu/nyikos
On 11/23/22 7:26 PM, Peter Nyikos wrote:
On Thursday, November 17, 2022 at 9:10:34 PM UTC-5, Peter Nyikos wrote:
On Wednesday, November 16, 2022 at 7:05:55 PM UTC-5, Trolidan7 wrote:
Thank you both for the links and references.Glad to be of help. I hope you keep following this thread,
because I have lots more to contribute to it.
Tomorrow, I will have a post on monotremes. Next week,
Monday, I'll have another on birds; then come marsupials.
The best laid plans of mice and men...
I hope you haven't given up waiting. Here is the post on monotremes;
then tomorrow,
unless my family has a very full schedule, comes the next one on birds.
Monotremes have a very sparse fossil record, but it goes back to the
early Cretaceous,
over 100 mya, when there were at least three different genera:
Steropodon, Kryoryctes, and Teinolophos.
Then, except for some disputed specimens, there is nothing until the
only non-Australian
known monotreme, Monotrematum sudamericanum – 61 million years old,
past the K-T
extinction event. Some classify it as a species of Obdurodon,
otherwise known from
the early Miocene (24 mya) to the very late Miocene, 5 mya. If the
identification
is correct, then Obdurodon was a "living fossil" by the time it became
extinct.
Obdurodon was quite similar to the living platypus, except that it had
some teeth
as an adult. The living platypus, Ornithorhynchus anatinus, only has
milk teeth
and when those are shed, only the familiar bill remains.
If Monotrematum was actually an Obdurodon, then it is quite probable
that Obdurodon was a K-T survivor, the lone monotreme with that
distinction.
A funny thing about all these monotremes: they all are believed
to be "duckbills" of some sort. The echidnas diverged from them
at some time and have obviously undergone some drastic changes in
their mouth parts.
Well, you know, surfing it some gives me the idea that for a
lot of this phenomena a lot of information is derived from
fossil tooth structure. I get the idea that Multituberculata
survived the K-T boundary, but they died out before the present.
It seems feasible to me that if they had survived to the
present they could have been classified as separate and
distinct among the living mammals like the monotremes.
Or would their reproductive strategies have been similar
enough to either the monotremes, marsupials, or placental
mammals for them to have been classified as curious members
of one of the others until recently through genetics?
I guess you can infer the existence of 'milk teeth'
from fossils. It is reasonable that theoretically
inferring from the existence of 'milk teeth' that members
of multituberculata gave or drank milk at some point in
their life cycle?
Peter Nyikos
Professor, Dept. of Mathematics
University of So. Carolina -- standard disclaimer--
http://people.math.sc.edu/nyikos
On 11/23/22 7:26 PM, Peter Nyikos wrote:
On Thursday, November 17, 2022 at 9:10:34 PM UTC-5, Peter Nyikos wrote:
On Wednesday, November 16, 2022 at 7:05:55 PM UTC-5, Trolidan7 wrote:
Thank you both for the links and references.Glad to be of help. I hope you keep following this thread,
because I have lots more to contribute to it.
Tomorrow, I will have a post on monotremes. Next week,
Monday, I'll have another on birds; then come marsupials.
The best laid plans of mice and men...
I hope you haven't given up waiting. Here is the post on monotremes; then tomorrow,
unless my family has a very full schedule, comes the next one on birds.
Monotremes have a very sparse fossil record, but it goes back to the early Cretaceous,
over 100 mya, when there were at least three different genera: Steropodon, Kryoryctes, and Teinolophos.
Then, except for some disputed specimens, there is nothing until the only non-Australian
known monotreme, Monotrematum sudamericanum – 61 million years old, past the K-T
extinction event. Some classify it as a species of Obdurodon, otherwise known from
the early Miocene (24 mya) to the very late Miocene, 5 mya. If the identification
is correct, then Obdurodon was a "living fossil" by the time it became extinct.
Obdurodon was quite similar to the living platypus, except that it had some teeth
as an adult. The living platypus, Ornithorhynchus anatinus, only has milk teeth
and when those are shed, only the familiar bill remains.
If Monotrematum was actually an Obdurodon, then it is quite probable
that Obdurodon was a K-T survivor, the lone monotreme with that distinction.
A funny thing about all these monotremes: they all are believed
to be "duckbills" of some sort. The echidnas diverged from them
at some time and have obviously undergone some drastic changes in their mouth parts.
Well, you know, surfing it some gives me the idea that for a
lot of this phenomena a lot of information is derived from
fossil tooth structure. I get the idea that Multituberculata
survived the K-T boundary, but they died out before the present.
It seems feasible to me that if they had survived to the
present they could have been classified as separate and
distinct among the living mammals like the monotremes.
Or would their reproductive strategies have been similar
enough to either the monotremes, marsupials, or placental
mammals for them to have been classified as curious members
of one of the others until recently through genetics?
I guess you can infer the existence of 'milk teeth'
from fossils.
It is reasonable that theoretically
inferring from the existence of 'milk teeth' that members
of multituberculata gave or drank milk at some point in
their life cycle?
On 10/26/22 12:57 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 10:14:35 PM UTC-4, John Harshman wrote:
On 10/21/22 1:36 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 3:24:55 PM UTC-4, John Harshman wrote: >>>> On 10/26/22 12:57 PM, Peter Nyikos wrote:
there are at least three bird lineages
surviving the K/P extinction.
Again, at least 7: paleognaths, neoaves, galliforms, anhimids,
presbyornithids, anseranatidae, anatidae.
Which bird did you have in mind from neoaves?
It's all implied by the tree if we suppose there are Cretaceous
presbyornithids and that presbyornithids are the sister group of
anatids. I wasn't referring to any other fossils.
This double-dipping (the same fossils for neoaves and presbyornithids) brings the total down to at most 6 but probably at most 5.
Beg pardon? I fail to understand your objection here. The point is that
if group X exists, so must its sister group.
By the way, are you using Cretaceous representatives of crown groups?
I mean crown anatiforms for the Cretaceous anatiforms, etc. (except of course
for the presbyornithids, which became extinct in the Miocene).
You mean "anseriforms" or possibly "anatids". Presbyornithids are crown
group anseriforms. If there are Cretaceous presbyornithinds, then there
must also be Cretaceous anatids, since they are sister groups.
This is my second reply to a post by John Harshman on another thread:
https://groups.google.com/g/sci.bio.paleontology/c/U-99grFea8E/m/vj8TF0RaAAAJ Re: Hesperornid Acquisition here in Columbia ATTN: Popping mad
That title long outlived its usefulness, and my first reply already
would already have been more appropriate here. It was: https://groups.google.com/g/sci.bio.paleontology/c/U-99grFea8E/m/K0OXzSgIAQAJ
On Wednesday, October 26, 2022 at 4:30:33 PM UTC-4, John Harshman wrote:
On 10/26/22 12:57 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 10:14:35 PM UTC-4, John Harshman wrote:
On 10/21/22 1:36 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 3:24:55 PM UTC-4, John Harshman wrote: >>>>>> On 10/26/22 12:57 PM, Peter Nyikos wrote:
Picking up almost where I left off in my first reply:
there are at least three bird lineages
surviving the K/P extinction.
Again, at least 7: paleognaths, neoaves, galliforms, anhimids,
presbyornithids, anseranatidae, anatidae.
Which bird did you have in mind from neoaves?
It's worth noting that the last 5 groups you list are all in Galloanserae. If, as is generally believed, the first split in Neornithes is between paleognaths and Galloanserae, you are assuming below that
Neoaves and Galloanserae are sister groups, right?
It's all implied by the tree if we suppose there are Cretaceous
presbyornithids and that presbyornithids are the sister group of
anatids. I wasn't referring to any other fossils.
The problem with that, as we saw in the first reply, is
that the claim of there being Cretaceous presbyornithids
is shaky. You need several generally accepted Cretaceous
members of Galloanserae to make the claim that there
were 7 lineages.
This double-dipping (the same fossils for neoaves and presbyornithids)
brings the total down to at most 6 but probably at most 5.
Beg pardon? I fail to understand your objection here. The point is that
if group X exists, so must its sister group.
Right, but how far does this generality take us? We need to be clear on where we are relying on this group X - sister talk, and where we
are relying on Cretaceous fossils.
By the way, are you using Cretaceous representatives of crown groups?
I mean crown anatiforms for the Cretaceous anatiforms, etc. (except of course
for the presbyornithids, which became extinct in the Miocene).
You mean "anseriforms" or possibly "anatids". Presbyornithids are crown
group anseriforms. If there are Cretaceous presbyornithinds, then there
must also be Cretaceous anatids, since they are sister groups.
There is that nasty word "if" again. Where are the generally accepted Cretaceous fossils?
On 11/25/22 7:56 PM, Peter Nyikos wrote:
On Wednesday, October 26, 2022 at 4:30:33 PM UTC-4, John Harshman wrote:
On 10/26/22 12:57 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 10:14:35 PM UTC-4, John Harshman wrote: >>>> On 10/21/22 1:36 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 3:24:55 PM UTC-4, John Harshman wrote: >>>>>> On 10/26/22 12:57 PM, Peter Nyikos wrote:
there are at least three bird lineages
surviving the K/P extinction.
Again, at least 7: paleognaths, neoaves, galliforms, anhimids,
presbyornithids, anseranatidae, anatidae.
Which bird did you have in mind from neoaves?
It's worth noting that the last 5 groups you list are all in Galloanserae.
If, as is generally believed, the first split in Neornithes is between paleognaths and Galloanserae, you are assuming below that
Neoaves and Galloanserae are sister groups, right?
It's all implied by the tree if we suppose there are Cretaceous
presbyornithids and that presbyornithids are the sister group of
anatids. I wasn't referring to any other fossils.
The problem with that, as we saw in the first reply, is
that the claim of there being Cretaceous presbyornithids
is shaky. You need several generally accepted Cretaceous
members of Galloanserae to make the claim that there
were 7 lineages.
No, you only need one, as long as it's the right one. Either a presbyornithid or an anatid would do.
Here is a claim of a Cretaceous presbyornithid:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785986/
One might also add Gastornithidae and Pelagornithidae, though I'm not
sure whether those are both separate branches.
On Sunday, November 27, 2022 at 1:07:11 AM UTC-5, John Harshman wrote:
On 11/25/22 7:56 PM, Peter Nyikos wrote:
On Wednesday, October 26, 2022 at 4:30:33 PM UTC-4, John Harshman wrote: >>>> On 10/26/22 12:57 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 10:14:35 PM UTC-4, John Harshman wrote: >>>>>> On 10/21/22 1:36 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 3:24:55 PM UTC-4, John Harshman wrote: >>>>>>>> On 10/26/22 12:57 PM, Peter Nyikos wrote:
there are at least three bird lineages
surviving the K/P extinction.
Again, at least 7: paleognaths, neoaves, galliforms, anhimids, >>>>>>>> presbyornithids, anseranatidae, anatidae.
Which bird did you have in mind from neoaves?
It's worth noting that the last 5 groups you list are all in Galloanserae.
And the last four are generally believed to be in Anseriformes ("waterfowl").
If, as is generally believed, the first split in Neornithes is between
paleognaths and Galloanserae, you are assuming below that
Neoaves and Galloanserae are sister groups, right?
You don't answer this, but I soon figured out that I was right here.
It's all implied by the tree if we suppose there are Cretaceous
presbyornithids and that presbyornithids are the sister group of
anatids. I wasn't referring to any other fossils.
The problem with that, as we saw in the first reply, is
that the claim of there being Cretaceous presbyornithids
is shaky. You need several generally accepted Cretaceous
members of Galloanserae to make the claim that there
were 7 lineages.
No, you only need one, as long as it's the right one. Either a
presbyornithid or an anatid would do.
You are assuming some other features of the phylogenetic tree
of the order Anseriformes ("waterfowl") that you aren't
identifying here. What are they?
the two cannot yet be resolved. In any case, recognition of W. tedfordi as a presbyornithid calls for a reassessment of the phylogenetic position of Presbyornithidae within Anseriformes."Here is a claim of a Cretaceous presbyornithid:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785986/
It sounds rather tentative, so not too encouraging of "only need one":
"Although screamers (Anhimidae) may have evolved from presbyornithid-like birds, the uncertainty as to whether skeletal features shared by presbyornithids and anhimids are plesiomorphic within Anseriformes or indicative of a close relationship between
Sounds like your hypothesis is much more easily falsifiable than the hypothesis that a
species of *Merychippus* is directly ancestral to *Equus* in the horse family.
One might also add Gastornithidae and Pelagornithidae, though I'm not
sure whether those are both separate branches.
Ah, one of my favorite bird families, those pelagornithids ["pseudotoothed birds"].
The biggest one of all, with a wingspread over 20 feet, was found right here in South Carolina, while clearing land for the Charleston international airport.
However, I saw no candidates for either family having Cretaceous members.
And whether they are separate branches or the same seems irrelevant.
You really have your work cut out for you to find an indirect phylogenetic tree way to make them survivors of the K-P extinction.
On 11/28/22 7:13 PM, Peter Nyikos wrote:
On Sunday, November 27, 2022 at 1:07:11 AM UTC-5, John Harshman wrote:
On 11/25/22 7:56 PM, Peter Nyikos wrote:
On Wednesday, October 26, 2022 at 4:30:33 PM UTC-4, John Harshman wrote: >>>> On 10/26/22 12:57 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 10:14:35 PM UTC-4, John Harshman wrote: >>>>>> On 10/21/22 1:36 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 3:24:55 PM UTC-4, John Harshman wrote:
On 10/26/22 12:57 PM, Peter Nyikos wrote:
there are at least three bird lineages
surviving the K/P extinction.
Again, at least 7: paleognaths, neoaves, galliforms, anhimids, >>>>>>>> presbyornithids, anseranatidae, anatidae.
Which bird did you have in mind from neoaves?
It's worth noting that the last 5 groups you list are all in Galloanserae.
And the last four are generally believed to be in Anseriformes ("waterfowl").
"Generally believed" is a very weak statement, and I'm not sure why you
put it that way.
Yes, they are anseriforms.
If, as is generally believed, the first split in Neornithes is between >>> paleognaths and Galloanserae, you are assuming below that
Neoaves and Galloanserae are sister groups, right?
You don't answer this, but I soon figured out that I was right here.
You are partly right and partly wrong. The first part of your sentence
is wrong
It's all implied by the tree if we suppose there are Cretaceous >>>>>> presbyornithids and that presbyornithids are the sister group of >>>>>> anatids. I wasn't referring to any other fossils.
The problem with that, as we saw in the first reply, is
that the claim of there being Cretaceous presbyornithids
is shaky. You need several generally accepted Cretaceous
members of Galloanserae to make the claim that there
were 7 lineages.
No, you only need one, as long as it's the right one. Either a
presbyornithid or an anatid would do.
You are assuming some other features of the phylogenetic tree
of the order Anseriformes ("waterfowl") that you aren't
identifying here. What are they?
Just the usual (and well-confirmed) relationships.
Are you in any doubt?
On 11/28/22 7:13 PM, Peter Nyikos wrote:
On Sunday, November 27, 2022 at 1:07:11 AM UTC-5, John Harshman wrote:
On 11/25/22 7:56 PM, Peter Nyikos wrote:
On Wednesday, October 26, 2022 at 4:30:33 PM UTC-4, John Harshman wrote: >>>> On 10/26/22 12:57 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 10:14:35 PM UTC-4, John Harshman wrote: >>>>>> On 10/21/22 1:36 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 3:24:55 PM UTC-4, John Harshman wrote:
On 10/26/22 12:57 PM, Peter Nyikos wrote:
there are at least three bird lineages
surviving the K/P extinction.
Again, at least 7: paleognaths, neoaves, galliforms, anhimids, >>>>>>>> presbyornithids, anseranatidae, anatidae.
between the two cannot yet be resolved. In any case, recognition of W. tedfordi as a presbyornithid calls for a reassessment of the phylogenetic position of Presbyornithidae within Anseriformes."Here is a claim of a Cretaceous presbyornithid:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785986/
It sounds rather tentative, so not too encouraging of "only need one":
"Although screamers (Anhimidae) may have evolved from presbyornithid-like birds, the uncertainty as to whether skeletal features shared by presbyornithids and anhimids are plesiomorphic within Anseriformes or indicative of a close relationship
Sounds like your hypothesis is much more easily falsifiable than the hypothesis that a
species of *Merychippus* is directly ancestral to *Equus* in the horse family.
??
One might also add Gastornithidae and Pelagornithidae, though I'm not
sure whether those are both separate branches.
Ah, one of my favorite bird families, those pelagornithids ["pseudotoothed birds"].
The biggest one of all, with a wingspread over 20 feet, was found right here
in South Carolina, while clearing land for the Charleston international airport.
However, I saw no candidates for either family having Cretaceous members. And whether they are separate branches or the same seems irrelevant.
You really have your work cut out for you to find an indirect phylogenetic tree way to make them survivors of the K-P extinction.
You still don't seem to understand how this works.
If we have a
Cretaceous example of a particular branch, all nodes below that branch
must also exist at that time. Given a Cretaceous presbyornithid, and
give tnat Presbyornithidae is the sister group of Anatidae, there must
be Cretaceous gastornithids and/or (depending on the tree)
pelagornithids, and anseranatids, anhimids, neoavians, and paleognaths.
On Tuesday, November 29, 2022 at 9:19:13 AM UTC-5, John Harshman wrote:
On 11/28/22 7:13 PM, Peter Nyikos wrote:
On Sunday, November 27, 2022 at 1:07:11 AM UTC-5, John Harshman wrote:
On 11/25/22 7:56 PM, Peter Nyikos wrote:
On Wednesday, October 26, 2022 at 4:30:33 PM UTC-4, John Harshman wrote: >>>>>> On 10/26/22 12:57 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 10:14:35 PM UTC-4, John Harshman wrote: >>>>>>>> On 10/21/22 1:36 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 3:24:55 PM UTC-4, John Harshman wrote: >>>>>>>>>> On 10/26/22 12:57 PM, Peter Nyikos wrote:
there are at least three bird lineages
surviving the K/P extinction.
Again, at least 7: paleognaths, neoaves, galliforms, anhimids, >>>>>>>>>> presbyornithids, anseranatidae, anatidae.
<snip to get to where I left off in my first reply>
between the two cannot yet be resolved. In any case, recognition of W. tedfordi as a presbyornithid calls for a reassessment of the phylogenetic position of Presbyornithidae within Anseriformes."Here is a claim of a Cretaceous presbyornithid:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785986/
It sounds rather tentative, so not too encouraging of "only need one":
"Although screamers (Anhimidae) may have evolved from presbyornithid-like birds, the uncertainty as to whether skeletal features shared by presbyornithids and anhimids are plesiomorphic within Anseriformes or indicative of a close relationship
Sounds like your hypothesis is much more easily falsifiable than the hypothesis that a
species of *Merychippus* is directly ancestral to *Equus* in the horse family.
??
Come on, John, the general theme of direct ancestry
has been a perennial bone of contention between us.
If you disagree in this instance, please explain your disagreement.
the beginning of the history of technology.[3]"One might also add Gastornithidae and Pelagornithidae, though I'm not
sure whether those are both separate branches.
Ah, one of my favorite bird families, those pelagornithids ["pseudotoothed birds"].
The biggest one of all, with a wingspread over 20 feet, was found right here
in South Carolina, while clearing land for the Charleston international airport.
I'm glad you mentioned them. I found out a fascinating piece of information from the
Wikipedia entry on them just now.
"They were the dominant seabirds of most oceans throughout most of the Cenozoic, and modern humans apparently missed encountering them only by a tiny measure of evolutionary time: the last known pelagornithids were contemporaries of Homo habilis and
So near and yet so far. :(
However, I saw no candidates for either family having Cretaceous members. >>> And whether they are separate branches or the same seems irrelevant.
You really have your work cut out for you to find an indirect phylogenetic >>> tree way to make them survivors of the K-P extinction.
You still don't seem to understand how this works.
I don't understand why you say this. You are ignoring the fact that Gastornis is considered by some to be within crown Anseriformes.
As for pelagornithids, the Wikipedia entry tentatively put them into Galloanserae,
but then treated us to a long discussion that reads like a technical review paper
of various proposed possibilities, including some "outliers" in Neoaves.
>If we have a
Cretaceous example of a particular branch, all nodes below that branch
must also exist at that time. Given a Cretaceous presbyornithid, and
give tnat Presbyornithidae is the sister group of Anatidae, there must
be Cretaceous gastornithids and/or (depending on the tree)
pelagornithids, and anseranatids, anhimids, neoavians, and paleognaths.
Too many assumptions here, in the light of my latest comments.
Add to them the possibility that Mayr gave [see my first reply to your post], that presbyornithids are outside Anseriformes, and you could be down to paleognaths, neoaves, galliforms, presbyornithids, and a cladogenesis
at some Paleocene member of total Anseriformes after anagenesis
(or evolutionary stasis) from where presbyornithids split off from from Anseriformes.
Five lineages, not seven.
On Tuesday, November 29, 2022 at 9:19:13 AM UTC-5, John Harshman wrote:skull bone of which more detailed descriptions exist, exhibits several presumably plesimorphic characteristics, which suggest a position of presbyornithids outside crown group Anseriformes [Elzanowski and Stidham 2010]."
On 11/28/22 7:13 PM, Peter Nyikos wrote:
On Sunday, November 27, 2022 at 1:07:11 AM UTC-5, John Harshman wrote:
On 11/25/22 7:56 PM, Peter Nyikos wrote:
On Wednesday, October 26, 2022 at 4:30:33 PM UTC-4, John Harshman wrote: >>>>>> On 10/26/22 12:57 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 10:14:35 PM UTC-4, John Harshman wrote: >>>>>>>> On 10/21/22 1:36 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 3:24:55 PM UTC-4, John Harshman wrote: >>>>>>>>>> On 10/26/22 12:57 PM, Peter Nyikos wrote:
there are at least three bird lineages
surviving the K/P extinction.
Again, at least 7: paleognaths, neoaves, galliforms, anhimids, >>>>>>>>>> presbyornithids, anseranatidae, anatidae.
Which bird did you have in mind from neoaves?
It's worth noting that the last 5 groups you list are all in Galloanserae.
And the last four are generally believed to be in Anseriformes ("waterfowl").
"Generally believed" is a very weak statement, and I'm not sure why you
put it that way.
Because Gerald Mayr, on p. 115 of his 2017 book, had some doubts about presbyornithids:
"Unfortunately, an assessment of the affinities of presbyornithids is hampered by the poorly known morphology of the skull, which has not yet been studied in detail, despite the availability of numerous well-preserved specimens. The quadrate, the only
Yes, they are anseriforms.
That's a very strong statement. :)
If, as is generally believed, the first split in Neornithes is between >>>>> paleognaths and Galloanserae, you are assuming below that
Neoaves and Galloanserae are sister groups, right?
You don't answer this, but I soon figured out that I was right here.
You are partly right and partly wrong. The first part of your sentence
is wrong
Sorry, I was absent-minded. I meant "neognaths" instead
of Galloanserae in the first part.
However, the possibility that there is a poorly resolved trichotomy
between the three groups occurred to me just now. Recall the example of {theropods, sauropods, ornithischians} at the base of Dinosauria.
Is it different with the base of Neornithes?
It's all implied by the tree if we suppose there are Cretaceous >>>>>>>> presbyornithids and that presbyornithids are the sister group of >>>>>>>> anatids. I wasn't referring to any other fossils.
The problem with that, as we saw in the first reply, is
that the claim of there being Cretaceous presbyornithids
is shaky. You need several generally accepted Cretaceous
members of Galloanserae to make the claim that there
were 7 lineages.
No, you only need one, as long as it's the right one. Either a
presbyornithid or an anatid would do.
You are assuming some other features of the phylogenetic tree
of the order Anseriformes ("waterfowl") that you aren't
identifying here. What are they?
Just the usual (and well-confirmed) relationships.
Why so tight-lipped? I suppose you are referring to the tree of Anseriformes in Wikipedia, but since when is Wikipedia an infallible guide to phylogeny?
Are you in any doubt?
Yes, whenever you are as tight-lipped as this. Besides, it's bad form:
what is sci.bio.paleontology for, if not for liberal conveying
of information among participants? I say "among" instead of "between"
because I think other regulars can benefit from a more informative
answer to the question I asked. That's why I wrote "waterfowl" after "Anseriformes" because there might be some readers who are unfamiliar
with the technical designations of bird orders.
CONCLUDED in next reply, to be done not long after I see
that this one has posted.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
Univ. of So. Carolina in Columbia
http://people.math.sc.edu/nyikos
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaurs
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow.
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos-
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,
and why did others, including some similar-seeming ones, perish?
On Wednesday, November 9, 2022 at 9:14:07 PM UTC-5, peter2...@gmail.com wrote:
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaurs
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which
hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow.
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Good catch! The actual article: https://www.nature.com/articles/s41586-022-05445-yPeter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,-
and why did others, including some similar-seeming ones, perish?
Not sure where to put this: https://www.nature.com/articles/d41586-022-04181-7
On 11/30/22 3:23 PM, Peter Nyikos wrote:
On Tuesday, November 29, 2022 at 9:19:13 AM UTC-5, John Harshman wrote:
On 11/28/22 7:13 PM, Peter Nyikos wrote:
On Sunday, November 27, 2022 at 1:07:11 AM UTC-5, John Harshman wrote: >>>> On 11/25/22 7:56 PM, Peter Nyikos wrote:
On Wednesday, October 26, 2022 at 4:30:33 PM UTC-4, John Harshman wrote:
On 10/26/22 12:57 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 10:14:35 PM UTC-4, John Harshman wrote:
On 10/21/22 1:36 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 3:24:55 PM UTC-4, John Harshman wrote:
On 10/26/22 12:57 PM, Peter Nyikos wrote:
there are at least three bird lineages
surviving the K/P extinction.
Again, at least 7: paleognaths, neoaves, galliforms, anhimids, >>>>>>>>>> presbyornithids, anseranatidae, anatidae.
<snip to get to where I left off in my first reply>
between the two cannot yet be resolved. In any case, recognition of W. tedfordi as a presbyornithid calls for a reassessment of the phylogenetic position of Presbyornithidae within Anseriformes."Here is a claim of a Cretaceous presbyornithid:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785986/
It sounds rather tentative, so not too encouraging of "only need one": >>>
"Although screamers (Anhimidae) may have evolved from presbyornithid-like birds, the uncertainty as to whether skeletal features shared by presbyornithids and anhimids are plesiomorphic within Anseriformes or indicative of a close relationship
Sounds like your hypothesis is much more easily falsifiable than the hypothesis that a
species of *Merychippus* is directly ancestral to *Equus* in the horse family.
??
Come on, John, the general theme of direct ancestry
has been a perennial bone of contention between us.
If you disagree in this instance, please explain your disagreement.
I truly don't know what you were trying to hint at there, so I don't
know whether I agree.
the beginning of the history of technology.[3]"One might also add Gastornithidae and Pelagornithidae, though I'm not >>>> sure whether those are both separate branches.
Ah, one of my favorite bird families, those pelagornithids ["pseudotoothed birds"].
The biggest one of all, with a wingspread over 20 feet, was found right here
in South Carolina, while clearing land for the Charleston international airport.
I'm glad you mentioned them. I found out a fascinating piece of information from the
Wikipedia entry on them just now.
"They were the dominant seabirds of most oceans throughout most of the Cenozoic, and modern humans apparently missed encountering them only by a tiny measure of evolutionary time: the last known pelagornithids were contemporaries of Homo habilis and
So near and yet so far. :(
Similar story for phorusrhacids.
However, I saw no candidates for either family having Cretaceous members.
And whether they are separate branches or the same seems irrelevant.
You really have your work cut out for you to find an indirect phylogenetic
tree way to make them survivors of the K-P extinction.
You still don't seem to understand how this works.
I don't understand why you say this. You are ignoring the fact that Gastornis
is considered by some to be within crown Anseriformes.
I'm not aware of that. Who?
As for pelagornithids, the Wikipedia entry tentatively put them into Galloanserae,
but then treated us to a long discussion that reads like a technical review paper
of various proposed possibilities, including some "outliers" in Neoaves.
Sounds like it was written by a very old specialist. Better to look for
pubs with actual phylogenetic analyses in them, none of which I have off-hand.
If we have a
Cretaceous example of a particular branch, all nodes below that branch
must also exist at that time. Given a Cretaceous presbyornithid, and
give tnat Presbyornithidae is the sister group of Anatidae, there must
be Cretaceous gastornithids and/or (depending on the tree)
pelagornithids, and anseranatids, anhimids, neoavians, and paleognaths.
Too many assumptions here, in the light of my latest comments.
Add to them the possibility that Mayr gave [see my first reply to your post],
that presbyornithids are outside Anseriformes, and you could be down to paleognaths, neoaves, galliforms, presbyornithids, and a cladogenesis
at some Paleocene member of total Anseriformes after anagenesis
(or evolutionary stasis) from where presbyornithids split off from from Anseriformes.
Five lineages, not seven.
Yes, that's possible, though whatever you are trying to say regarding anagenesis is unclear.
Just "anseriforms" would have been simpler and
more correct.
So we're agreed that you don't need more than one
Cretaceous fossil to infer the Cretaceous existence of several other
groups.
On Wednesday, November 9, 2022 at 9:14:07 PM UTC-5, peter2...@gmail.com wrote:
PS The "Why?" at the end of the thread title is two-edged: why did some survive,-
and why did others, including some similar-seeming ones, perish?
Not sure where to put this:
https://www.nature.com/articles/d41586-022-04181-7
On Wednesday, November 9, 2022 at 9:14:07 PM UTC-5, peter2...@gmail.com wrote:
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaurs-
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great
that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote
ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which >> hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow.
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,
and why did others, including some similar-seeming ones, perish?
Not sure where to put this: https://www.nature.com/articles/d41586-022-04181-7
On 12/1/22 10:18 PM, Daud Deden wrote:
On Wednesday, November 9, 2022 at 9:14:07 PM UTC-5, peter2...@gmail.com wrote:As usual in science journalism, the title (at least) is hype. This
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaurs-
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great >> that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote
ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which
hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow.
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,
and why did others, including some similar-seeming ones, perish?
Not sure where to put this: https://www.nature.com/articles/d41586-022-04181-7
discovery has no effect on the evolutionary tree, just on the character state at the base of the tree. Paleognaths and neognaths are still each monophyletic. No change there.
On Wednesday, November 30, 2022 at 7:49:38 PM UTC-5, John Harshman wrote:between the two cannot yet be resolved. In any case, recognition of W. tedfordi as a presbyornithid calls for a reassessment of the phylogenetic position of Presbyornithidae within Anseriformes."
On 11/30/22 3:23 PM, Peter Nyikos wrote:
On Tuesday, November 29, 2022 at 9:19:13 AM UTC-5, John Harshman wrote: >>>> On 11/28/22 7:13 PM, Peter Nyikos wrote:
On Sunday, November 27, 2022 at 1:07:11 AM UTC-5, John Harshman wrote: >>>>>> On 11/25/22 7:56 PM, Peter Nyikos wrote:
On Wednesday, October 26, 2022 at 4:30:33 PM UTC-4, John Harshman wrote:
On 10/26/22 12:57 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 10:14:35 PM UTC-4, John Harshman wrote:
On 10/21/22 1:36 PM, Peter Nyikos wrote:
On Friday, October 21, 2022 at 3:24:55 PM UTC-4, John Harshman wrote:
On 10/26/22 12:57 PM, Peter Nyikos wrote:
there are at least three bird lineages
surviving the K/P extinction.
Again, at least 7: paleognaths, neoaves, galliforms, anhimids, >>>>>>>>>>>> presbyornithids, anseranatidae, anatidae.
<snip to get to where I left off in my first reply>
Here is a claim of a Cretaceous presbyornithid:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785986/
It sounds rather tentative, so not too encouraging of "only need one": >>>>>
"Although screamers (Anhimidae) may have evolved from presbyornithid-like birds, the uncertainty as to whether skeletal features shared by presbyornithids and anhimids are plesiomorphic within Anseriformes or indicative of a close relationship
Sounds like your hypothesis is much more easily falsifiable than the hypothesis that a
species of *Merychippus* is directly ancestral to *Equus* in the horse family.
??
Come on, John, the general theme of direct ancestry
has been a perennial bone of contention between us.
If you disagree in this instance, please explain your disagreement.
I truly don't know what you were trying to hint at there, so I don't
know whether I agree.
I was not "hinting".
What part of "your hypothesis is much more easily falsifiable than"
don't you understand? We have essentially complete fossils of Merychippus and can study Equus to our heart's content.
Compare that to the evidence that *Teviornis gobiensis* was a Cretaceous presbyornithid.
Mayr's 2017 book doesn't even mention the genus nor the 2016 paper that we have been
discussing above. Neither does Wikipedia, which only cites two papers on the genus,
in 2002 and 2004. Do you know of any citations of it in the peer-reviewed literature?
Or any more recent evidence for its tentative conclusion?
It's an awfully thin peg to hang 7 separate lineages on.
the beginning of the history of technology.[3]"One might also add Gastornithidae and Pelagornithidae, though I'm not >>>>>> sure whether those are both separate branches.
Ah, one of my favorite bird families, those pelagornithids ["pseudotoothed birds"].
The biggest one of all, with a wingspread over 20 feet, was found right here
in South Carolina, while clearing land for the Charleston international airport.
I'm glad you mentioned them. I found out a fascinating piece of information from the
Wikipedia entry on them just now.
"They were the dominant seabirds of most oceans throughout most of the Cenozoic, and modern humans apparently missed encountering them only by a tiny measure of evolutionary time: the last known pelagornithids were contemporaries of Homo habilis and
So near and yet so far. :(
Similar story for phorusrhacids.
Even more so: put Homo erectus there. However, the much more recent claims of ca.100 kya
and even 18 kya are not well supported according to the entry on them.
The summary in the box at upper right should have a question mark added after 0.1 Ma.
Another case of discordant statements on the same Wiki page.
However, I saw no candidates for either family having Cretaceous members. >>>>> And whether they are separate branches or the same seems irrelevant. >>>>> You really have your work cut out for you to find an indirect phylogenetic
tree way to make them survivors of the K-P extinction.
You still don't seem to understand how this works.
I don't understand why you say this. You are ignoring the fact that Gastornis
is considered by some to be within crown Anseriformes.
I'm not aware of that. Who?
Read the Wikipedia entry.
As for pelagornithids, the Wikipedia entry tentatively put them into Galloanserae,
but then treated us to a long discussion that reads like a technical review paper
of various proposed possibilities, including some "outliers" in Neoaves.
Sounds like it was written by a very old specialist. Better to look for
pubs with actual phylogenetic analyses in them, none of which I have
off-hand.
Please let us know when you find any. But keep in mind that the
reviewer cites a number of them already.
If we have aToo many assumptions here, in the light of my latest comments.
Cretaceous example of a particular branch, all nodes below that branch >>>> must also exist at that time. Given a Cretaceous presbyornithid, and
give tnat Presbyornithidae is the sister group of Anatidae, there must >>>> be Cretaceous gastornithids and/or (depending on the tree)
pelagornithids, and anseranatids, anhimids, neoavians, and paleognaths. >>>
Add to them the possibility that Mayr gave [see my first reply to your post],
that presbyornithids are outside Anseriformes, and you could be down to
paleognaths, neoaves, galliforms, presbyornithids, and a cladogenesis
at some Paleocene member of total Anseriformes after anagenesis
(or evolutionary stasis) from where presbyornithids split off from from Anseriformes.
Five lineages, not seven.
Yes, that's possible, though whatever you are trying to say regarding
anagenesis is unclear.
One or more speciations without branching. The old species may
linger on for a while, but in the absence of fossils for side branches,
there is no evidence for cladogenesis.
We're talking about lineages, not individual taxa.
Just "anseriforms" would have been simpler and
more correct.
How so? doesn't it mean the same thing as Anseriformes?
So we're agreed that you don't need more than one
Cretaceous fossil to infer the Cretaceous existence of several other
groups.
Of course, but the fossil involved in this case is fragmentary.
I've asked Trevor Worthy last night (my time; this morning his time)
in email about how the 2016 paper has fared since then, and I hope he answers before long.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
U. of South Carolina at Columbia
http://people.math.sc.edu/nyikos
On Friday, December 2, 2022 at 7:52:41 PM UTC-5, John Harshman wrote:
On 12/1/22 10:18 PM, Daud Deden wrote:
On Wednesday, November 9, 2022 at 9:14:07 PM UTC-5, peter2...@gmail.com wrote:
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaurs-
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great
that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote >> ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which
hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow.
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,
and why did others, including some similar-seeming ones, perish?
Not sure where to put this: https://www.nature.com/articles/d41586-022-04181-7
As usual in science journalism, the title (at least) is hype.
This discovery has no effect on the evolutionary tree, just on the character
state at the base of the tree. Paleognaths and neognaths are still each monophyletic. No change there.
OT streamlined theropod natovenator no wings https://www.nature.com/articles/s42003-022-04119-9
Short on time, I address both of the first two posts listed below:palaeognathous. Instead, these observations support the hypothesis that the extant palaeognathous condition is derived and convergent with the superficially similar morphologies found in stemward avialans and non-avialan theropods. Indeed, the pronounced
On Friday, December 2, 2022 at 8:08:42 PM UTC-5, daud....@gmail.com wrote:
On Friday, December 2, 2022 at 7:52:41 PM UTC-5, John Harshman wrote:
On 12/1/22 10:18 PM, Daud Deden wrote:
On Wednesday, November 9, 2022 at 9:14:07 PM UTC-5, peter2...@gmail.com wrote:
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaurs-
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great
that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote
ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which
hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow. >>
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,
and why did others, including some similar-seeming ones, perish?
Not sure where to put this: https://www.nature.com/articles/d41586-022-04181-7
I don't know why John said this. Chances are he didn't look at the research articleAs usual in science journalism, the title (at least) is hype.
that Erik linked for us. I skimmed it for less than a minute, and the following
leaped out at me:
"Nonetheless, the notably galloanseran-like pterygoid of Janavis, together with recent evidence of a neognath-like hemipterygoid–palatine complex in Ichthyornis12, rejects the hypothesis that the plesiomorphic condition of the neornithine palate was
--"Cretaceous ornithurine supports a neognathous crown bird ancestor" https://www.nature.com/articles/s41586-022-05445-y
Why, the very title should have made John think twice before posting the following:
Unfortunately for John, Erik did not post the title, only the nondescriptive url.This discovery has no effect on the evolutionary tree, just on the character
state at the base of the tree. Paleognaths and neognaths are still each monophyletic. No change there.
And so we have this priceless irony.
On Friday, December 2, 2022 at 5:53:31 PM UTC-8, peter2...@gmail.com wrote:was palaeognathous. Instead, these observations support the hypothesis that the extant palaeognathous condition is derived and convergent with the superficially similar morphologies found in stemward avialans and non-avialan theropods. Indeed, the
Short on time, I address both of the first two posts listed below:
On Friday, December 2, 2022 at 8:08:42 PM UTC-5, daud....@gmail.com wrote:
On Friday, December 2, 2022 at 7:52:41 PM UTC-5, John Harshman wrote:
On 12/1/22 10:18 PM, Daud Deden wrote:
On Wednesday, November 9, 2022 at 9:14:07 PM UTC-5, peter2...@gmail.com wrote:
The Great K-T extinction spelled the doom of the giant sea reptiles, all dinosaurs-
(unless you count birds as dinosaurs), and many other groups of vertebrates and invertebrates.
In fact, the damage caused by the asteroid that hit Yucatan was so great
that no animal over 50 kilos is known to have survived.
But some groups of birds and mammals did survive, including the remote
ancestors
of the four groups that have survived to this day: the neornithine birds and three groups of mammals:
the placentals, the marsupials, and the monotremes.
To keep this OP reasonably short, I will deal with the two most familiar of the four, the placentals and the modern birds.
A 2013 _Science_ article [1] led to the general acceptance of the hypothesis that all living placentals
have descended from a common ancestor that lived after the great K-T disaster.
However, there are closely related eutherians [2] that also survived for a while, among
whose descendants were the pantodonts, including *Coryphodon*, which was a bit larger than a tapir; and the tillodonts and taeniodonts. These groups died out during the Eocene, which ended almost halfway between the K-T disaster and our time.
The case of birds is generally believed to be quite different: EVERY bird, living
or extinct, that survived the K-T disaster is believed to be descended from the
last common ancestor of living birds. However, there are some articles which
hypothesize that there is one exception, a group of birds called the lithornids.
More about them in my next post to this thread, some time tomorrow. >>
[1] Maureen A. O'Leary et. al., "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667.
[2] Eutherians are the mammals, extant and extinct, that are more closely related to placentals than to marsupials.
Similarly, metatherians are the mammals that are more closely related to marsupials than to placentals.
Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos
PS The "Why?" at the end of the thread title is two-edged: why did some survive,
and why did others, including some similar-seeming ones, perish?
Not sure where to put this: https://www.nature.com/articles/d41586-022-04181-7
I don't know why John said this. Chances are he didn't look at the research articleAs usual in science journalism, the title (at least) is hype.
that Erik linked for us. I skimmed it for less than a minute, and the following
leaped out at me:
"Nonetheless, the notably galloanseran-like pterygoid of Janavis, together with recent evidence of a neognath-like hemipterygoid–palatine complex in Ichthyornis12, rejects the hypothesis that the plesiomorphic condition of the neornithine palate
--"Cretaceous ornithurine supports a neognathous crown bird ancestor" https://www.nature.com/articles/s41586-022-05445-y
Why, the very title should have made John think twice before posting the following:What priceless irony? Maybe you should try reading the article for a little more than
Unfortunately for John, Erik did not post the title, only the nondescriptive url.This discovery has no effect on the evolutionary tree, just on the character
state at the base of the tree. Paleognaths and neognaths are still each
monophyletic. No change there.
And so we have this priceless irony.
a minute, and maybe even think a bit about what the "message" is. Hint: consider
what the term ‘palaeognathous condition’ is, and what its phylogentic implications are.
The reference given for the "early days of systematic ornithology" is itself a glimpse of
good old-time phylogeny circa 1948, with references going back as far as Huxley
himself (1867). Thirty pages of exquisite anaysis of the bony palate of paleognaths.
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