New and historical specimens of burnetiamorph therapsids, with comments on ontogeny, biogeography, and bizarre structures

Simple item page
dc.contributor.authorSidor, Christian A.
dc.date.accessioned2023-07-18T19:03:29Z
dc.date.available2023-07-18T19:03:29Z
dc.date.issued2023-07
dc.description.abstractFor much of its history, the fossil record of burnetiamorph therapsids was both species poor and known from very few specimens. By contrast, the past two decades have seen a dramatic increase in both measures of the group’s fossil record. Here I introduce two new species, Bondoceras bulborhynchus gen. et sp. nov. and Pembecephalus litumbaensis gen. et sp. nov., from the Guadalupian middle Madumabisa Mudstone Formation of Zambia and the Lopingian Usili Formation of Tanzania, respectively. Both are based on a series of isolated skullcaps that preserve a unique combination of characters that suggest referral to subclades within Burnetiidae. Historical burnetiamorph skullcaps collected in Tanzania in the early 1930s are figured, but these are kept in open nomenclature because not enough information is preserved to warrant assigning them to Pembecephalus or another genus. A previously undescribed Russian burnetiamorph is also figured, which is only the third specimen of the clade known from the northern hemisphere, but since the specimen is possibly lost, it is also left unnamed. Specimens referred to Bondoceras and Pembecephalus suggest that while some morphological features vary predictably with size in these burnetiamorphs, others do not, and that some features previously used to assess ontogenetic status in burnetiamorphs are sometimes similarly problematic. Despite their wide range of shapes, surprisingly little discussion of the function of burnetiamorph cranial adornments has taken place in the literature. Comparing the fossil records of burnetiamorphs and other Permian synapsids to dinosaurs with similar adornments may shed light on the macroevolutionary importance of these traits.
dc.description.librarianJNC2023
dc.description.sponsorshipGENUS: DSI-NRF Centre of Excellence in Palaeosciences
dc.identifier.urihttps://hdl.handle.net/10539/35696
dc.rightsCopyright 2023 the Authors. This is an open-access article published under the Creative Commons Attribution 4.0 Unported License (CC BY4.0). To view a copy of the license, please visit http://creativecommons.org/licenses/by/4.0/. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
dc.titleNew and historical specimens of burnetiamorph therapsids, with comments on ontogeny, biogeography, and bizarre structures
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
SIDOR_2023 burnetiamorphs.pdf
Size:
17.72 MB
Format:
Adobe Portable Document Format
Description:
Updated version of record containing Zoobank IDs for new taxonomic acts
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
2.43 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Volume 56: 2023