(2022) described a supposed crown-group cnidarian from the Ediacaran of Charnwood Forest in the UK. The latter authors concluded that “early annulated tubular exoskeletons from the latest Ediacaran and Cambrian are better understood as variations on cnidarian exoskeletons rather than early annelids.” Third Studyįinally, Dunn et al. My hypothesis ( Bechly 2022) that all the tube-like Ediacaran fossils with a stacked composition of the sclerotized tubes do represent burrowing cnidarians, has been strongly supported by the discovery that similar phosphatized and annulated tube-like fossils from the Cambrian were not worms but indeed cnidarians ( Zhang et al. They also possess a lengthy gastrovascular cavity that could be misinterpreted as an annelid-like gut in the fossils. However, the authors “propose an alternative hypothesis for the phylogenetic affinity of the cloudinid-like tubular organisms,” because recent cnidarian polyps of coronate scyphozoan affinity produce tubes that are superficially similar and often conflated with polychaete tubes. This would leave the theoretical possibility that those “cloudinomorphs” (e.g., Saarina and Costatubus) indeed were bilaterian worms with a convergent similarity to cloudinids.
#Discovery park denton series
(2021) identified “derived characters linking some members of an enigmatic animal group, the cloudinids, which first appeared in the Late Ediacaran, to animals with cnidarian affinity from the Cambrian Series 2 and the Miaolingian.” These authors also mentioned that the alleged cloudinomorpha with preserved gut lack the characteristic funnel-in-funnel structure of the tubes and thus may be unrelated to typical cloudinids. (2020): a problematic group of shelly fossils, which were almost certainly not bilaterian worms, but quite possibly related to cnidarians.” My conclusion has since then been strongly corroborated by three new studies.
This should support the existence of a hypothetical late Ediacaran “worm world.” I criticized this interpretation and the taxonomic attribution and concluded that “cloudinomorphs remain what they were before the recent paper by Schiffbauer et al. (2020) to represent bilaterian worms because of a preserved longitudinal structure that was interpreted by these authors as a digestive tract. In a previous article series at Evolution News I discussed and debunked various alleged Precambrian animals, including the tube-like cloudinomorphs ( Bechly 2020), which had recently been claimed by Schiffbauer et al.
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