https://www.sciencedaily.com/releases/2022/09/220928113007.htm
On 10/3/22 8:38 PM, Daud Deden wrote:
https://www.sciencedaily.com/releases/2022/09/220928113007.htm
Well, this is cool. Here's the abstract of the real publication.
https://www.nature.com/articles/s41586-022-04897-6
Full body fossils of galeaspids; very exciting.
On Monday, October 3, 2022 at 8:53:21 PM UTC-7, John Harshman wrote:
On 10/3/22 8:38 PM, Daud Deden wrote:
https://www.sciencedaily.com/releases/2022/09/220928113007.htm
Well, this is cool. Here's the abstract of the real publication.
https://www.nature.com/articles/s41586-022-04897-6
Full body fossils of galeaspids; very exciting.Here, shit yourself silly:
https://phys.org/news/2022-09-dead-fish-life-evolutionary-fins.html
On 10/3/22 8:38 PM, Daud Deden wrote:
https://www.sciencedaily.com/releases/2022/09/220928113007.htm
Well, this is cool. Here's the abstract of the real publication.
https://www.nature.com/articles/s41586-022-04897-6
Full body fossils of galeaspids; very exciting.
On Monday, October 3, 2022 at 11:53:21 PM UTC-4, John Harshman wrote:
On 10/3/22 8:38 PM, Daud Deden wrote:
https://www.sciencedaily.com/releases/2022/09/220928113007.htm
Well, this is cool. Here's the abstract of the real publication.
https://www.nature.com/articles/s41586-022-04897-6
Full body fossils of galeaspids; very exciting.
I hadn't expected it to be a freshwater dweller.
On 10/3/22 11:13 PM, Daud Deden wrote:
On Monday, October 3, 2022 at 11:53:21 PM UTC-4, John Harshman wrote:
On 10/3/22 8:38 PM, Daud Deden wrote:
https://www.sciencedaily.com/releases/2022/09/220928113007.htm
Well, this is cool. Here's the abstract of the real publication.
https://www.nature.com/articles/s41586-022-04897-6
Full body fossils of galeaspids; very exciting.
I hadn't expected it to be a freshwater dweller.Is there a clear and obvious understanding of what
fish fossils are supposed to be freshwater and what
fish fossils are supposed to be marine?
I would guess that if there is understanding of that
for many species, it would involve looking at the
sediments that the fossils are embedded in?
I am getting the idea that paleontologists in general
consider marine osteichthyes to be derived from freshwater
fish, with the general evidence being the existence of
at least vestigal kidneys in marine fish species, as well
as the salinity of the blood of osteichthyes, but there might
be some more direct evidence as well?
In general, how do marine fish lower the salinity of their
blood? Can kidneys actually reduce the salinity of blood
beyond the salinity of ingested seawater or is some other
process used? I am thinking that marine turtles 'cry'
hypersaline 'tears' into the water but I am not sure about
bony fish.
If it is possible for kidneys to produce urine that is
more saline than seawater, then why do paleontologists
think that kidneys are evidence that osteichthyes in
general is derived from freshwater species? Or do
paleontologists not actually hold this view to begin
with?
On Monday, October 3, 2022 at 8:53:21 PM UTC-7, John Harshman wrote:
On 10/3/22 8:38 PM, Daud Deden wrote:
https://www.sciencedaily.com/releases/2022/09/220928113007.htm
Well, this is cool. Here's the abstract of the real publication.
https://www.nature.com/articles/s41586-022-04897-6
Full body fossils of galeaspids; very exciting.
Here, shit yourself silly:
https://phys.org/news/2022-09-dead-fish-life-evolutionary-fins.html
This is my first look at this thread, and I am disappointedto-tail fin precursor."
by the lack of interest in the main hypothesis of the authors.
Glenn's lack of interest I can understand; but why nothing from John?
Glenn, on the other hand, did us all a service by finding a
non-paywalled popularization with magnificent illustrations
based on the ones in the paywalled (but available to me
through my university) _Nature_ article.
On Tuesday, October 4, 2022 at 12:26:18 AM UTC-4, Glenn wrote:
On Monday, October 3, 2022 at 8:53:21 PM UTC-7, John Harshman wrote:
On 10/3/22 8:38 PM, Daud Deden wrote:
https://www.sciencedaily.com/releases/2022/09/220928113007.htm
Well, this is cool. Here's the abstract of the real publication.
Strange use of words: "cool" vs "real".
Not cool enough to provide pictures, though.
https://www.nature.com/articles/s41586-022-04897-6
Full body fossils of galeaspids; very exciting.
No mention of what makes it exciting for paleontologists:
instead of paired fins, the fossils of these Silurian fish are
interpreted as having very narrow fin folds extending
all along the body:
"Perhaps the most unexpected feature of the postcranial anatomy of galeaspids is a pair of pronounced ventrolateral fins that extend continuously from a branchial to a caudal position, effectively bifurcating from the ventral lobe of the caudal fin."
[from the _Nature_ article]
Their significance is hypothesized to be as follows:
"Corresponding author Professor Donoghue said, "Tujiaaspis breathes new life into a century old hypothesis for the evolution of paired fins, through differentiation of pectoral (arms) and pelvic (legs) fins over evolutionary time from a continuous head-
-- from the popularization linked by Glenn below.
However, there is a disquieting feature that seems to rule out anything
like a direct ancestral role to Tujiaaspis or closely related taxa:
"A small oval orifice preserved in the midline of the abdominal area at about half of the body length is probably the anal opening (cloaca), but no anal fin is observed posterior to the anus (Figs. 1 and 2f)."
[from the paywalled part of the _Nature_ article]
Ironically, had Glenn known about this, it would have given him an excuse
for the following inappropriate language:
Here, shit yourself silly:
Crikey, why not tell us the really interesting thing:
this is the first of the three non-paywalled references with illustrations. And it even has something lacking in the paywalled part of the
article: a 10-second video originating in China that shows the
artists' conception of the fish swimming, with views from many angles.
https://phys.org/news/2022-09-dead-fish-life-evolutionary-fins.html
On Tuesday, October 11, 2022 at 11:30:31 AM UTC-4, John Harshman wrote:head-to-tail fin precursor."
On 10/11/22 7:18 AM, Peter Nyikos wrote:
This is my first look at this thread, and I am disappointed
by the lack of interest in the main hypothesis of the authors.
Glenn's lack of interest I can understand; but why nothing from John?
Glenn, on the other hand, did us all a service by finding a
non-paywalled popularization with magnificent illustrations
based on the ones in the paywalled (but available to me
through my university) _Nature_ article.
On Tuesday, October 4, 2022 at 12:26:18 AM UTC-4, Glenn wrote:
On Monday, October 3, 2022 at 8:53:21 PM UTC-7, John Harshman wrote:
On 10/3/22 8:38 PM, Daud Deden wrote:
https://www.sciencedaily.com/releases/2022/09/220928113007.htm
Well, this is cool. Here's the abstract of the real publication.
Strange use of words: "cool" vs "real".
Not cool enough to provide pictures, though.
https://www.nature.com/articles/s41586-022-04897-6
Full body fossils of galeaspids; very exciting.
No mention of what makes it exciting for paleontologists:
instead of paired fins, the fossils of these Silurian fish are
interpreted as having very narrow fin folds extending
all along the body:
"Perhaps the most unexpected feature of the postcranial anatomy of galeaspids is a pair of pronounced ventrolateral fins that extend continuously from a branchial to a caudal position, effectively bifurcating from the ventral lobe of the caudal fin."
[from the _Nature_ article]
Their significance is hypothesized to be as follows:
"Corresponding author Professor Donoghue said, "Tujiaaspis breathes new life into a century old hypothesis for the evolution of paired fins, through differentiation of pectoral (arms) and pelvic (legs) fins over evolutionary time from a continuous
-- from the popularization linked by Glenn below.
However, there is a disquieting feature that seems to rule out anything
like a direct ancestral role to Tujiaaspis or closely related taxa:
"A small oval orifice preserved in the midline of the abdominal area at about half of the body length is probably the anal opening (cloaca), but no anal fin is observed posterior to the anus (Figs. 1 and 2f)."
[from the paywalled part of the _Nature_ article]
Ironically, had Glenn known about this, it would have given him an excuse >>> for the following inappropriate language:
Here, shit yourself silly:
Crikey, why not tell us the really interesting thing:
this is the first of the three non-paywalled references with illustrations. >>> And it even has something lacking in the paywalled part of the
article: a 10-second video originating in China that shows the
artists' conception of the fish swimming, with views from many angles.
https://phys.org/news/2022-09-dead-fish-life-evolutionary-fins.html
When you pepper your posts with personal attacks and replies to quotes
several layers deep it makes me less inclined to respond.
These words would have weight if you had bothered to
say something on-topic that befits your educational level.
You had a whole week to do it. Yet you don't do it even now.
Whatever happened to the John Harshman who would do unmarked
snips to personal comments that offended him, and would then respond
to the on-topic comments? Have you lost your interest in responding to them?
As it is, you come across like a spoiled child who tries to manipulate others into catering to his whims ("makes me less inclined").
I have been planning to do a thread on reproduction in coelacanths,
and ran out of time yesterday. I was about to begin now,
and even to add lungfishes to the study. But your behavior here
makes me wonder whether you will ever try to
make comments that move the topic forward.
Peter Nyikos
PS When you wrote "personal attacks" were you only thinking
of yourself, and not Glenn also?
On 10/11/22 7:18 AM, Peter Nyikos wrote:head-to-tail fin precursor."
This is my first look at this thread, and I am disappointed
by the lack of interest in the main hypothesis of the authors.
Glenn's lack of interest I can understand; but why nothing from John?
Glenn, on the other hand, did us all a service by finding a
non-paywalled popularization with magnificent illustrations
based on the ones in the paywalled (but available to me
through my university) _Nature_ article.
On Tuesday, October 4, 2022 at 12:26:18 AM UTC-4, Glenn wrote:
On Monday, October 3, 2022 at 8:53:21 PM UTC-7, John Harshman wrote:
On 10/3/22 8:38 PM, Daud Deden wrote:
https://www.sciencedaily.com/releases/2022/09/220928113007.htm
Well, this is cool. Here's the abstract of the real publication.
Strange use of words: "cool" vs "real".
Not cool enough to provide pictures, though.
https://www.nature.com/articles/s41586-022-04897-6
Full body fossils of galeaspids; very exciting.
No mention of what makes it exciting for paleontologists:
instead of paired fins, the fossils of these Silurian fish are
interpreted as having very narrow fin folds extending
all along the body:
"Perhaps the most unexpected feature of the postcranial anatomy of galeaspids is a pair of pronounced ventrolateral fins that extend continuously from a branchial to a caudal position, effectively bifurcating from the ventral lobe of the caudal fin."
[from the _Nature_ article]
Their significance is hypothesized to be as follows:
"Corresponding author Professor Donoghue said, "Tujiaaspis breathes new life into a century old hypothesis for the evolution of paired fins, through differentiation of pectoral (arms) and pelvic (legs) fins over evolutionary time from a continuous
-- from the popularization linked by Glenn below.
However, there is a disquieting feature that seems to rule out anything like a direct ancestral role to Tujiaaspis or closely related taxa:
"A small oval orifice preserved in the midline of the abdominal area at about half of the body length is probably the anal opening (cloaca), but no anal fin is observed posterior to the anus (Figs. 1 and 2f)."
[from the paywalled part of the _Nature_ article]
Ironically, had Glenn known about this, it would have given him an excuse for the following inappropriate language:
Here, shit yourself silly:
Crikey, why not tell us the really interesting thing:
this is the first of the three non-paywalled references with illustrations.
And it even has something lacking in the paywalled part of the
article: a 10-second video originating in China that shows the
artists' conception of the fish swimming, with views from many angles.
https://phys.org/news/2022-09-dead-fish-life-evolutionary-fins.html
When you pepper your posts with personal attacks and replies to quotes several layers deep it makes me less inclined to respond.
On Tuesday, October 4, 2022 at 6:51:14 PM UTC-4, Trolidan7 wrote:
On 10/3/22 11:13 PM, Daud Deden wrote:
On Monday, October 3, 2022 at 11:53:21 PM UTC-4, John Harshman wrote:
On 10/3/22 8:38 PM, Daud Deden wrote:
https://www.sciencedaily.com/releases/2022/09/220928113007.htm
Well, this is cool. Here's the abstract of the real publication.
https://www.nature.com/articles/s41586-022-04897-6
Full body fossils of galeaspids; very exciting.
I hadn't expected it to be a freshwater dweller.
Is there a clear and obvious understanding of what
fish fossils are supposed to be freshwater and what
fish fossils are supposed to be marine?
I would guess that if there is understanding of that
for many species, it would involve looking at the
sediments that the fossils are embedded in?
I am getting the idea that paleontologists in general
consider marine osteichthyes to be derived from freshwater
fish, with the general evidence being the existence of
at least vestigal kidneys in marine fish species, as well
as the salinity of the blood of osteichthyes, but there might
be some more direct evidence as well?
In general, how do marine fish lower the salinity of their
blood? Can kidneys actually reduce the salinity of blood
beyond the salinity of ingested seawater or is some other
process used? I am thinking that marine turtles 'cry'
hypersaline 'tears' into the water but I am not sure about
bony fish.
If it is possible for kidneys to produce urine that is
more saline than seawater, then why do paleontologists
think that kidneys are evidence that osteichthyes in
general is derived from freshwater species? Or do
paleontologists not actually hold this view to begin
with?
Trolidan, this may help?
Per r norman at SAP:
Invertebrates and early chordates, like the hagfish (myxine), have
body fluids very similar to sea water, which has not changed that much
in the half billion years.
There are differences in individual ion
concentrations, but the osmotic pressure is very close. The later vertebrates are a completely different story, having salt
concentrations far lower. One major hypothesis (frankly, I do not
know whether it is universally accepted) is that they evolved in fresh water. Modern marine vertebrates including sharks, bony fish,
reptiles, birds, and amphibians, reinvaded the ocean afterwards.
So the body fluids of humans, mammals, and tetrapods in general is
much lower than sea water not because sea water was more dilute back
then but because they inherited that feature from freshwater
ancestors.
https://www.sciencedaily.com/releases/2022/09/220928113007.htm
| Sysop: | Keyop |
|---|---|
| Location: | Huddersfield, West Yorkshire, UK |
| Users: | 302 |
| Nodes: | 16 (2 / 14) |
| Uptime: | 98:10:52 |
| Calls: | 6,767 |
| Calls today: | 5 |
| Files: | 12,295 |
| Messages: | 5,376,388 |
| Posted today: | 1 |