Imperial College London
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Dr. Martin D. Brazeau

Faculty of Natural Sciences, Department of Life Sciences (Silwood Park)

Senior Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 2254m.brazeau

 
 
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Location

 

W3.1KennedySilwood Park

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Summary

 

Publications

Citation

BibTex format

@article{Brazeau:2020:10.1038/s41559-020-01290-2,
author = {Brazeau, MD and Giles, S and Dearden, RP and Jerve, A and Ariunchimeg, Y and Zorig, E and Sansom, R and Guillerme, T and Castiello, M},
doi = {10.1038/s41559-020-01290-2},
journal = {Nature Ecology and Evolution},
pages = {1477--1484},
title = {Endochondral bone in an early devonian ‘placoderm’ from Mongolia},
url = {http://dx.doi.org/10.1038/s41559-020-01290-2},
volume = {4},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - 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.
AU  - Brazeau,MD
AU  - Giles,S
AU  - Dearden,RP
AU  - Jerve,A
AU  - Ariunchimeg,Y
AU  - Zorig,E
AU  - Sansom,R
AU  - Guillerme,T
AU  - Castiello,M
DO  - 10.1038/s41559-020-01290-2
EP  - 1484
PY  - 2020///
SN  - 2397-334X
SP  - 1477
TI  - Endochondral bone in an early devonian ‘placoderm’ from Mongolia
T2  - Nature Ecology and Evolution
UR  - http://dx.doi.org/10.1038/s41559-020-01290-2
UR  - https://www.nature.com/articles/s41559-020-01290-2
UR  - http://hdl.handle.net/10044/1/82739
VL  - 4
ER  -
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