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| Cantabrigiaster fezouataensis from the Lower Ordovician (Tremadocian) Fezouata Shale, Zagora Morocco Credit: Collection of Yale University |
Researchers from Cambridge University's Earth Sciences and Zoology Departments have identified an Ordovician period fossil, about about 450-million-years-old, from Morocco's Anti-Atlas Mountains as intermediate between the sea lilies or Crinoids and modern starfish. The Ordovician was a period of rapid diversification starting about 485.4 million years ago immediately after the Cambrian and lasting until about 443.8 million years ago.
Regular find like this must be acutely embarrassing for the Creationist frauds who tell their credulous dupes that the absence of these transitional forms in the fossil record means Darwin's TOE is falsified!
"If you went back in time and put your head under the sea in the Ordovician then you wouldn’t recognize any of the marine organisms - except the starfish, they are one of the first modern animals"
The Cambridge University News iten explains:
Aaron Hunter
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| Cantabrigiaster fezouataensis from the Lower Ordovician (Tremadocian) of Morocco. Holotype UCBL-FSL 424961 (Van Roy coll.). (a) Oral view (body fossil). (b) Interpretative diagram of (a). (c) Close-up of extended arm (latex mould). (d) Interpretative diagram of (c). (e) Close-up of oral region (latex mould). (f) Interpretative diagram of (e). am, ambulacral ossicles; co, circumoral ossicles; cr, carinal region ossicles (preserved on the aboral surface); map, mouth angle plates; mc, mouth cavity; pb, podial basins; ps, podial suture; vr, virgal ossicles. |
The prototype starfish, which has features in common with both sea lilies and modern-day starfish, is a missing link for scientists trying to piece together its early evolutionary history.
The exceptionally preserved fossil, named Cantabrigiaster fezouataensis, was discovered in Morocco’s Anti-Atlas mountain range. Its intricate design – with feathery arms akin to a lacework – has been frozen in time for roughly 480 million years.
The new species is unusual because it doesn’t have many of the key features of its contemporary relatives, lacking roughly 60% of a modern starfish’s body plan.
The fossil’s features are instead a hybrid between those of a starfish and a sea lily or crinoid - not a plant but a wavy-armed filter feeder which fixes itself to the seabed via a cylindrical ‘stem’.
The discovery, reported in Biology Letters, captures the early evolutionary steps of the animal at a time in Earth’s history when life suddenly expanded, a period known as the Ordovician Biodiversification Event.
The find also means scientists can now use the new find as a template to work out how it evolved from this more basic form to the complexity of their contemporaries.
“Finding this missing link to their ancestors is incredibly exciting. If you went back in time and put your head under the sea in the Ordovician then you wouldn’t recognize any of the marine organisms - except the starfish, they are one of the first modern animals,” said lead author Dr Aaron Hunter, a visiting postdoctoral researcher in the Department of Earth Sciences.
Modern starfish and brittle stars are part of a family of spiny-skinned animals called the echinoderms which, although they don’t have a backbone, are one of the closest group of animals to vertebrates. Crinoids, and otherworldly creatures like the sea urchins and sea cucumbers are all echinoderms.
The origin of starfish has eluded scientists for decades. But the new species is so well preserved that its body can finally be mapped in detail and its evolution understood. “The level of detail in the fossil is amazing – its structure is so complex that it took us a while to unravel its significance,” said Hunter.
Copyright: © 2021 Cambridge Univrsity.
Reprinted under a Creative Commons Attribution 4.0 International License (CC BY 4.0)
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| A modern-day sea lily from Hawaii, Proisocrinus ruberrimus Credit: NOAA Ocean Research and Exploration |
Our results illuminate the ancestral morphology of Asterozoa, and clarify the affinities of problematic Ordovician Asterozoa. Bayesian inference and parsimony demonstrate that somasteroids represent a paraphyletic grade within stem- and crown-group Asterozoa, whereas stenuroids are paraphyletic within stem-group Ophiuroidea. Our results also offer potential insights on the evolutionary relationships between asterozoans, crinoids and potential Cambrian stem-group representatives.Once again then we have another of those pesky transitional fossils that show a clear common origin of two extant species whose relationship was previously unknown.
And once again we have a scientific paper that refutes another sacred Creationist dogma quite incidentally and without any intent on behalf of the researchers, simply by revealing the facts. You would think that, when their claims, dogmas and assertions are shown to be wrong so regularly and so obviously, Creationists would start to wonder if there is maybe a flaw in their belief, but perhaps I'm assuming a level of intellectual honesty and integrity which just isn't there.
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