5
IRUS Total
Downloads
  Altmetric

Endochondral bone in an early devonian ‘placoderm’ from Mongolia

File Description SizeFormat 
Archive_version.pdfAccepted version4.45 MBAdobe PDFView/Open
Title: Endochondral bone in an early devonian ‘placoderm’ from Mongolia
Authors: Brazeau, MD
Giles, S
Dearden, RP
Jerve, A
Ariunchimeg, Y
Zorig, E
Sansom, R
Guillerme, T
Castiello, M
Item Type: Journal Article
Abstract: Endochondral bone is the main internal skeletal tissue of nearly all osteichthyans—the group comprising more than 60,000 living species of bony fishes and tetrapods. Chondrichthyans (sharks and their kin) are the living sister group of osteichthyans and have primarily cartilaginous endoskeletons, long considered the ancestral condition for all jawed vertebrates (gnathostomes). The absence of bone in modern jawless fishes and the absence of endochondral ossification in early fossil gnathostomes appear to lend support to this conclusion. Here we report the discovery of extensive endochondral bone in Minjinia turgenensis, a new genus and species of ‘placoderm’-like fish from the Early Devonian (Pragian) of western Mongolia described using X-ray computed microtomography. The fossil consists of a partial skull roof and braincase with anatomical details providing strong evidence of placement in the gnathostome stem group. However, its endochondral space is filled with an extensive network of fine trabeculae resembling the endochondral bone of osteichthyans. Phylogenetic analyses place this new taxon as a proximate sister group of the gnathostome crown. These results provide direct support for theories of generalized bone loss in chondrichthyans. Furthermore, they revive theories of a phylogenetically deeper origin of endochondral bone and its absence in chondrichthyans as a secondary condition.
Issue Date: 1-Nov-2020
Date of Acceptance: 23-Jul-2020
URI: http://hdl.handle.net/10044/1/82739
DOI: 10.1038/s41559-020-01290-2
ISSN: 2397-334X
Publisher: Nature Research
Start Page: 1477
End Page: 1484
Journal / Book Title: Nature Ecology and Evolution
Volume: 4
Copyright Statement: © The Author(s), under exclusive licence to Springer Nature Limited 2020. The final publication is available at Springer via https://doi.org/10.1038/s41559-020-01290-2
Sponsor/Funder: Commission of the European Communities
Funder's Grant Number: 311092
Keywords: Science & Technology
Life Sciences & Biomedicine
Ecology
Evolutionary Biology
Environmental Sciences & Ecology
EARLY EVOLUTION
PHYLOGENY
INSIGHTS
ORIGIN
GENOME
Animals
Fossils
Jaw
Mongolia
Phylogeny
Skull
Skull
Jaw
Animals
Phylogeny
Fossils
Mongolia
Publication Status: Published
Online Publication Date: 2020-09-07
Appears in Collections:Faculty of Natural Sciences