https://www.nature.com/articles/s41586-024-07520-y (not open access)Possible alarm bell: https://www.researchgate.net/figure/Phylogenetic-position-of-Helicolocellus-cantori-gen-et-sp-nov-All-taxa-coded-in-the_fig4_381194576
A late-Ediacaran crown-group sponge animal
-a-a-a Xiaopeng Wang, Alexander G. Liu, Zhe Chen, Chengxi Wu, Yarong Liu, Bin Wan, Ke Pang, Chuanming Zhou, Xunlai Yuan & Shuhai Xiao
Abstract
Sponges are the most basal metazoan phylum1 and may have played
important roles in modulating the redox architecture of Neoproterozoic oceans2. Although molecular clocks predict that sponges diverged in the Neoproterozoic era3,4, their fossils have not been unequivocally demonstrated before the Cambrian period5,6,7,8, possibly because
Precambrian sponges were aspiculate and non-biomineralized9. Here we describe a late-Ediacaran fossil, Helicolocellus cantori gen. et sp.
nov., from the Dengying Formation (around 551rCo539rCemillion years ago) of South China. This fossil is reconstructed as a large, stemmed benthic organism with a goblet-shaped body more than 0.4rCem in height, with a
body wall consisting of at least three orders of nested grids defined by quadrate fields, resembling a Cantor dust fractal pattern. The resulting lattice is interpreted as an organic skeleton comprising orthogonally arranged cruciform elements, architecturally similar to some
hexactinellid sponges, although the latter are built with biomineralized spicules. A Bayesian phylogenetic analysis resolves H. cantori as a crown-group sponge related to the Hexactinellida. H. cantori confirms
that sponges diverged and existed in the Precambrian as
non-biomineralizing animals with an organic skeleton. Considering that siliceous biomineralization may have evolved independently among sponge classes10,11,12,13, we question the validity of biomineralized spicules
as a necessary criterion for the identification of Precambrian sponge fossils.
Very interesting find.-a I'm trying to find a PDF.
On 6/14/24 2:10 PM, erik simpson wrote:
https://www.nature.com/articles/s41586-024-07520-y (not open access)Possible alarm bell: https://www.researchgate.net/figure/Phylogenetic-position-of-Helicolocellus-cantori-gen-et-sp-nov-All-taxa-coded-in-the_fig4_381194576 presents a figure indicating a close relationship between Cnidaria and Ctenophora, which no longer considered valid.
A late-Ediacaran crown-group sponge animal
-a-a-a-a Xiaopeng Wang, Alexander G. Liu, Zhe Chen, Chengxi Wu, Yarong
Liu, Bin Wan, Ke Pang, Chuanming Zhou, Xunlai Yuan & Shuhai Xiao
Abstract
Sponges are the most basal metazoan phylum1 and may have played
important roles in modulating the redox architecture of Neoproterozoic
oceans2. Although molecular clocks predict that sponges diverged in
the Neoproterozoic era3,4, their fossils have not been unequivocally
demonstrated before the Cambrian period5,6,7,8, possibly because
Precambrian sponges were aspiculate and non-biomineralized9. Here we
describe a late-Ediacaran fossil, Helicolocellus cantori gen. et sp.
nov., from the Dengying Formation (around 551rCo539rCemillion years ago)
of South China. This fossil is reconstructed as a large, stemmed
benthic organism with a goblet-shaped body more than 0.4rCem in height,
with a body wall consisting of at least three orders of nested grids
defined by quadrate fields, resembling a Cantor dust fractal pattern.
The resulting lattice is interpreted as an organic skeleton comprising
orthogonally arranged cruciform elements, architecturally similar to
some hexactinellid sponges, although the latter are built with
biomineralized spicules. A Bayesian phylogenetic analysis resolves H.
cantori as a crown-group sponge related to the Hexactinellida. H.
cantori confirms that sponges diverged and existed in the Precambrian
as non-biomineralizing animals with an organic skeleton. Considering
that siliceous biomineralization may have evolved independently among
sponge classes10,11,12,13, we question the validity of biomineralized
spicules as a necessary criterion for the identification of
Precambrian sponge fossils.
Very interesting find.-a I'm trying to find a PDF.
On 6/14/24 3:21 PM, erik simpson wrote:
On 6/14/24 2:10 PM, erik simpson wrote:
https://www.nature.com/articles/s41586-024-07520-y (not open access)Possible alarm bell:
A late-Ediacaran crown-group sponge animal
-a-a-a-a Xiaopeng Wang, Alexander G. Liu, Zhe Chen, Chengxi Wu, Yarong
Liu, Bin Wan, Ke Pang, Chuanming Zhou, Xunlai Yuan & Shuhai Xiao
Abstract
Sponges are the most basal metazoan phylum1 and may have played
important roles in modulating the redox architecture of
Neoproterozoic oceans2. Although molecular clocks predict that
sponges diverged in the Neoproterozoic era3,4, their fossils have not
been unequivocally demonstrated before the Cambrian period5,6,7,8,
possibly because Precambrian sponges were aspiculate and
non-biomineralized9. Here we describe a late-Ediacaran fossil,
Helicolocellus cantori gen. et sp. nov., from the Dengying Formation
(around 551rCo539rCemillion years ago) of South China. This fossil is
reconstructed as a large, stemmed benthic organism with a
goblet-shaped body more than 0.4rCem in height, with a body wall
consisting of at least three orders of nested grids defined by
quadrate fields, resembling a Cantor dust fractal pattern. The
resulting lattice is interpreted as an organic skeleton comprising
orthogonally arranged cruciform elements, architecturally similar to
some hexactinellid sponges, although the latter are built with
biomineralized spicules. A Bayesian phylogenetic analysis resolves H.
cantori as a crown-group sponge related to the Hexactinellida. H.
cantori confirms that sponges diverged and existed in the Precambrian
as non-biomineralizing animals with an organic skeleton. Considering
that siliceous biomineralization may have evolved independently among
sponge classes10,11,12,13, we question the validity of biomineralized
spicules as a necessary criterion for the identification of
Precambrian sponge fossils.
Very interesting find.-a I'm trying to find a PDF.
https://www.researchgate.net/figure/Phylogenetic-position-of-Helicolocellus-cantori-gen-et-sp-nov-All-taxa-coded-in-the_fig4_381194576 presents a figure indicating a close relationship between Cnidaria and Ctenophora, which no longer considered valid.
Be not afraid. The bootstrap value for that node is only 57%,
essentially meaningless.
On 6/14/24 3:50 PM, John Harshman wrote:Glad to hear it. It doesn't matter much to the main subject anyway.
On 6/14/24 3:21 PM, erik simpson wrote:
On 6/14/24 2:10 PM, erik simpson wrote:
https://www.nature.com/articles/s41586-024-07520-y (not open access)Possible alarm bell:
A late-Ediacaran crown-group sponge animal
-a-a-a-a Xiaopeng Wang, Alexander G. Liu, Zhe Chen, Chengxi Wu, Yarong >>>> Liu, Bin Wan, Ke Pang, Chuanming Zhou, Xunlai Yuan & Shuhai Xiao
Abstract
Sponges are the most basal metazoan phylum1 and may have played
important roles in modulating the redox architecture of
Neoproterozoic oceans2. Although molecular clocks predict that
sponges diverged in the Neoproterozoic era3,4, their fossils have
not been unequivocally demonstrated before the Cambrian
period5,6,7,8, possibly because Precambrian sponges were aspiculate
and non-biomineralized9. Here we describe a late-Ediacaran fossil,
Helicolocellus cantori gen. et sp. nov., from the Dengying Formation
(around 551rCo539rCemillion years ago) of South China. This fossil is >>>> reconstructed as a large, stemmed benthic organism with a
goblet-shaped body more than 0.4rCem in height, with a body wall
consisting of at least three orders of nested grids defined by
quadrate fields, resembling a Cantor dust fractal pattern. The
resulting lattice is interpreted as an organic skeleton comprising
orthogonally arranged cruciform elements, architecturally similar to
some hexactinellid sponges, although the latter are built with
biomineralized spicules. A Bayesian phylogenetic analysis resolves
H. cantori as a crown-group sponge related to the Hexactinellida. H.
cantori confirms that sponges diverged and existed in the
Precambrian as non-biomineralizing animals with an organic skeleton.
Considering that siliceous biomineralization may have evolved
independently among sponge classes10,11,12,13, we question the
validity of biomineralized spicules as a necessary criterion for the
identification of Precambrian sponge fossils.
Very interesting find.-a I'm trying to find a PDF.
https://www.researchgate.net/figure/Phylogenetic-position-of-Helicolocellus-cantori-gen-et-sp-nov-All-taxa-coded-in-the_fig4_381194576 presents a figure indicating a close relationship between Cnidaria and Ctenophora, which no longer considered valid.
Be not afraid. The bootstrap value for that node is only 57%,
essentially meaningless.
Oops, sorry. Those are Bayesian posteriors, even more meaningless.
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