New Ediacaran fossils; new ones with meal study (Introduction)

by David Turell , Wednesday, November 23, 2022, 17:10 (731 days ago) @ David Turell

A summary of several Ediacarans with a diet study:

https://www.cell.com/current-biology/fulltext/S0960-9822(22)01699-2?dgcid=raven_jbs_aip...

"Bobrovskiy et al. examine the biomarker composition of Ediacaran macrofossils
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Kimberella and Calyptrina preserve molecular signatures of their gut content
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Kimberella and Calyptrina shared a mixed diet of green algae and bacteria
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Dickinsonia had no gut and potentially fed using external digestion

"Summary
The oldest animals appear in the fossil record among Ediacara biota communities. They prelude animal-dominated ecosystems of the Phanerozoic and may hold clues to the appearance of modern animal phyla in the Cambrian explosion. However, little is known about the phylogeny of the Ediacaran organisms and even less about their diet and feeding behavior. An exception is mollusc-like Kimberella, for which a fossilized gut, feeding traces, and even potential coprolites have been found. By contrast, Ediacaran organic-walled tubes, such as Sabellidites and Calyptrina, are thought to belong to tube worms comparable with modern Siboglinidae that have no gut but gain their nutrition from symbiotic bacteria. Here, we examine the gut contents of Ediacaran animals using biomarker molecules. We show that 558-million-year (Ma)-old tube worm-like Calyptrina and mollusc-like Kimberella possessed a gut and shared a diet of green algae and bacteria. Despite their ancient age, sterol metabolism within the gut of both organisms was already comparable to extant invertebrates. 8 Dickinsonia, one of the key Ediacaran animals, show no traces of dietary molecules, indicating a different feeding mode and possible external digestion analogous to modern Placozoa. Lipid biomarkers uncover a range of feeding strategies in Ediacaran communities, highlighting true eumetazoan physiology of some Ediacaran animals."

Comment: we knew they had to eat and are early animals but not anywhere near as complex as Cambrian's