A case of mistaken identity: ‘Latvius’ obrutus and new dipnoans from the Frasnian of Stolbovo, Russia
- Published
- Accepted
- Subject Areas
- Paleontology
- Keywords
- Lungfish, Dipnoi, Russia, Frasnian, Palaeobiogeography, Devonian, Endocast
- Copyright
- © 2017 Challands et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2017. A case of mistaken identity: ‘Latvius’ obrutus and new dipnoans from the Frasnian of Stolbovo, Russia. PeerJ Preprints 5:e3231v1 https://doi.org/10.7287/peerj.preprints.3231v1
Abstract
The village of Stolbovo, western Russia, has previously yielded a dipnoan fauna comprising the long-snouted form 'Rhinodipterus' stolbovi, but also a three-dimensionally preserved otoccipital region of a skull previously identified as the osteolepiform ‘Latvius’ obrutus. This identification was made from the density of lateral line canal pores in the skull roof bones in addition to what Vorobyeva (1977) described as the post-parietal, tabular and extratabular bones. Reexamination of this specimen does not recognise the osteolepiform dermal elements previously identified but rather a dipnoan configuration including a characteristic B-bone, lateral dermal elements and a dipnoan parasphenoid. rhinodipterid and dipterid dipnoans. Phylogenetic analysis resolves ‘Latvius’ obrutus as the primitive sister taxon to the ‘phaneropleurid-fleurantiid’ clade – a clade comprising derived Middle–Upper Devonian lungfishes. 'Rhinodipterus' stolbovi resolves among the more primitive griphognathids, typical Gondwanan forms, and is not a rhinodipterid. Additional isolated dipnoan skeletal elements from the site include tooth plates, parasphenoids, shoulder girdle elements and dermal elements and indicate at least an additional three lungfish taxa from Stolbovo. Of particular note is a ctenodiform tooth plate more characteristic of Carboniferous lungfishes. The new material and analyses not only demonstrate increased lungfish diversity from the Frasnian of Baltica but also probable interchange between Gondwana and Baltica during this time. Most importantly, Carboniferous-like forms appear more common in the Devonian than previously realised indicating that Carboniferous lungfishes likely represent a survival assemblage in addition to a new radiation of lungfish.
Author Comment
This is an abstract which has been accepted for the SVPCA/SPPC 2017 conference