Another item i'd missed, but of considerable interest to fans of the early Ediacaran:

https://www.nature.com/articles/s42003-020-01381-7

From the Conclusions:

"The Portfjeld Formation crops out over hundreds of kilometers in North Greenland but is poorly known on account of its remoteness. The assemblage of extremely well-preserved microfossils presented here, and its striking similarity to previously
described fossils from the Doushantuo Formation of China, demonstrates greater complexity and worldwide distribution of the late Ediacaran ecosystem than previously recognized. The finds from North Greenland extend the known distribution of the Ediacaran
Doushantuo-like biota along the length of the Pannotian palaeocontinent, from low to middle latitudes in the northern hemisphere (China) to the middle latitude position in the southern hemisphere occupied by North Greenland in eastern Laurentia; their
age is confirmed by chemostratigraphy.

With a background in the largely unexplored potential represented by the Portfjeld Formation, the new discoveries offer excellent prospects for resolving the phylogenetic relationships of many of these problematic multicellular Ediacaran eukaryotes and a
better understanding of the environments in which they evolved."

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On Monday, October 3, 2022 at 12:04:32 AM UTC-4, erik simpson wrote:

Another item i'd missed, but of considerable interest to fans of the early Ediacaran:

https://www.nature.com/articles/s42003-020-01381-7

From the Conclusions:

"The Portfjeld Formation crops out over hundreds of kilometers in North Greenland but is poorly known on account of its remoteness. The assemblage of extremely well-preserved microfossils presented here, and its striking similarity to previously

described fossils from the Doushantuo Formation of China, demonstrates greater complexity and worldwide distribution of the late Ediacaran ecosystem than previously recognized. The finds from North Greenland extend the known distribution of the Ediacaran
Doushantuo-like biota along the length of the Pannotian palaeocontinent, from low to middle latitudes in the northern hemisphere (China) to the middle latitude position in the southern hemisphere occupied by North Greenland in eastern Laurentia; their
age is confirmed by chemostratigraphy.

With a background in the largely unexplored potential represented by the Portfjeld Formation, the new discoveries offer excellent prospects for resolving the phylogenetic relationships of many of these problematic multicellular Ediacaran eukaryotes and

a better understanding of the environments in which they evolved."

Note the "eukaryotes" in the last sentence.

It looks like one author was responsible for the conclusion and another for the abstract,
and neither bothered to read what the other wrote in the respective places.

From the Abstract:
"The Portfjeld biota consists of three-dimensionally preserved putative eggs and embryos, as well as acanthomorphic and leiosphaeric acritarchs, red algal thalli, sheet-like and oscillatoriacean cyanobacteria, and microbial mat fragments."

Cyanobacteria are prokaryotes; it would be astounding if the author of the "Conclusion" didn't know that.
Also, "microbial mats" could be composed partly or wholly of prokaryotes.

Also, "acritarchs" are a "wastebasket taxon" that could include prokaryotes:

"Acritarchs are organic microfossils, known from approximately 1800 million years ago to the present. The classification is a catch all term used to refer to any organic microfossils that cannot be assigned to other groups."
--https://en.wikipedia.org/wiki/Acritarch

Curiously, neither "acanthomorphic" nor "leiosphaeric" is in the above webpage,
but there are approximations there:
Acanthodiacrodium (Ordovician)
and
Leiosphaeridia (Cambrian-Silurian)

Thus it appears that the author of the abstract was going on superficial resemblances (phenetics?)
to justify his two terms. "acanthomorphic" seems to be well established (10 hits in the article)
but the only hit for "leiosphaeric" is the one I've quoted above.


One other immediate reaction:

The great majority of popular science on these fossils has been aimed at the hypothesis
that they are examples of animal embryos. Yet they could range over any number of eukaryotic clades, and also prokaryotic.

For example, note the term "oscillatoriacean cyanobacteria" again. *Oscillatoria* is a well known multicellular prokaryote
found in high school labs and biological supply companies.


Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On Monday, October 3, 2022 at 10:25:17 AM UTC-7, peter2...@gmail.com wrote:

On Monday, October 3, 2022 at 12:04:32 AM UTC-4, erik simpson wrote:

Another item i'd missed, but of considerable interest to fans of the early Ediacaran:

https://www.nature.com/articles/s42003-020-01381-7

From the Conclusions:

"The Portfjeld Formation crops out over hundreds of kilometers in North Greenland but is poorly known on account of its remoteness. The assemblage of extremely well-preserved microfossils presented here, and its striking similarity to previously

described fossils from the Doushantuo Formation of China, demonstrates greater complexity and worldwide distribution of the late Ediacaran ecosystem than previously recognized. The finds from North Greenland extend the known distribution of the Ediacaran
Doushantuo-like biota along the length of the Pannotian palaeocontinent, from low to middle latitudes in the northern hemisphere (China) to the middle latitude position in the southern hemisphere occupied by North Greenland in eastern Laurentia; their
age is confirmed by chemostratigraphy.

With a background in the largely unexplored potential represented by the Portfjeld Formation, the new discoveries offer excellent prospects for resolving the phylogenetic relationships of many of these problematic multicellular Ediacaran eukaryotes

and a better understanding of the environments in which they evolved."

Note the "eukaryotes" in the last sentence.

It looks like one author was responsible for the conclusion and another for the abstract,
and neither bothered to read what the other wrote in the respective places.

From the Abstract:
"The Portfjeld biota consists of three-dimensionally preserved putative eggs and embryos, as well as acanthomorphic and leiosphaeric acritarchs, red algal thalli, sheet-like and oscillatoriacean cyanobacteria, and microbial mat fragments."

Cyanobacteria are prokaryotes; it would be astounding if the author of the "Conclusion" didn't know that.
Also, "microbial mats" could be composed partly or wholly of prokaryotes.

Also, "acritarchs" are a "wastebasket taxon" that could include prokaryotes:

"Acritarchs are organic microfossils, known from approximately 1800 million years ago to the present. The classification is a catch all term used to refer to any organic microfossils that cannot be assigned to other groups."
--https://en.wikipedia.org/wiki/Acritarch

Curiously, neither "acanthomorphic" nor "leiosphaeric" is in the above webpage,
but there are approximations there:
Acanthodiacrodium (Ordovician)
and
Leiosphaeridia (Cambrian-Silurian)

Thus it appears that the author of the abstract was going on superficial resemblances (phenetics?)
to justify his two terms. "acanthomorphic" seems to be well established (10 hits in the article)
but the only hit for "leiosphaeric" is the one I've quoted above.

One other immediate reaction:

The great majority of popular science on these fossils has been aimed at the hypothesis
that they are examples of animal embryos. Yet they could range over any number
of eukaryotic clades, and also prokaryotic.

For example, note the term "oscillatoriacean cyanobacteria" again. *Oscillatoria* is a well known multicellular prokaryote
found in high school labs and biological supply companies.

Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos

The main point of this paper isn't to present any new insights into the phylogeny of this fossil assemblage. Those topics have
an extensive literature attached to the Doushantuo Formation. Controversy accompanies almost all of the suggestions. The
samples discussed in this paper were collected in 1978(!) and apparently not been described before, and are of considerable
interest in that they reveal that the Doushantuo conditions and biota represent a widely-distributed environment, and is in no
appreciable way unique.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)