Protocinctus

{{speciesbox

| fossil_range = Miaolingian (Wuliuan), {{Geological range|506.5|504.5}}

| image = Kapli et al. 2021 f05b (cropped) Protocinctus.jpg

| image_caption = Ventral view of a specimen of Protocinctus mansillaensis

| image2 =

| image2_caption =

| genus = Protocinctus

| parent_authority = Rahman & Zamora, 2009

| species = mansillaensis

| authority = Rahman & Zamora, 2009

}}

Protocinctus is a genus of cinctan and, {{as of|2024|lc=y}}, it is the oldest such recognized genus. It is known from the Wuliuan age of the Mansilla Formation, Zaragoza, Spain. It is represented by the single species Protocinctus mansillaensis.

Description

The genus bears a combination of characters unique to cinctans, with an elongated oval-shaped theca with a single anterior left marginal feeding groove, and a posterior marginal frame open in posterior ventral view.

Like other cinctans, they would have been active pharyngeal filter feeders. The animal would lay close to the sediment surface with the anterior region oriented downstream and generate an inhalant flow of water directing suspended food particles to the mouth.

References

{{Reflist|refs=

{{Cite journal |last1=Zamora |first1=Samuel |last2=Wright |first2=David F. |last3=Nohejlová |first3=Martina |date=2023 |title=Phylogenetic position of Bohemiacinctus gen. nov. (Echinodermata, Cincta) from the Cambrian of Bohemia: implications for macroevolution and the role of taxon sampling in palaeobiological systematics |url=https://onlinelibrary.wiley.com/doi/10.1002/spp2.1482 |journal=Papers in Palaeontology |language=en |volume=9 |issue=1 |pages=e1482 |doi=10.1002/spp2.1482 |bibcode=2023PPal....9E1482Z |issn=2056-2802}}

{{Cite journal |last1=Rahman |first1=Imran A |last2=Zamora |first2=Samuel |date=September 2009 |title=The oldest cinctan carpoid (stem-group Echinodermata), and the evolution of the water vascular system |url=https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00517.x |journal=Zoological Journal of the Linnean Society |language=en |volume=157 |issue=2 |pages=420–432 |doi=10.1111/j.1096-3642.2008.00517.x}}

{{Cite journal |last1=Rahman |first1=Imran A. |last2=Zamora |first2=Samuel |last3=Falkingham |first3=Peter L. |last4=Phillips |first4=Jeremy C. |date=2015-11-07 |title=Cambrian cinctan echinoderms shed light on feeding in the ancestral deuterostome |journal=Proceedings of the Royal Society B: Biological Sciences |volume=282 |issue=1818 |pages=20151964 |doi=10.1098/rspb.2015.1964 |pmc=4650160 |pmid=26511049}}

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Category:Carboniferous echinoderms

Category:Homalozoa

Category:Prehistoric echinoderm genera