Fossils reveal the complex evolutionary history of the mammalian regionalized spine

K E Jones, K. D. Angielczyk, P David Polly, J. J. Head, V. Fernandez, J. Lungmus, S. Tulga, S E Pierce

Research output: Contribution to journalArticlepeer-review


A unique characteristic of mammals is a vertebral column with anatomically distinct regions, but when and how this trait evolved remains unknown. We reconstructed vertebral regions and their morphological disparity in the extinct forerunners of mammals, the nonmammalian synapsids, to elucidate the evolution of mammalian axial differentiation. Mapping patterns of regionalization and disparity (heterogeneity) across amniotes reveals that both traits increased during synapsid evolution. However, the onset of regionalization predates increased heterogeneity. On the basis of inferred homology patterns, we propose a "pectoral-first" hypothesis for region acquisition, whereby evolutionary shifts in forelimb function in nonmammalian therapsids drove increasing vertebral modularity prior to differentiation of the vertebral column for specialized functions in mammals.
Original languageEnglish
Pages (from-to)1249–1252
Early online date21 Sept 2018
Publication statusPublished - 2018


Dive into the research topics of 'Fossils reveal the complex evolutionary history of the mammalian regionalized spine'. Together they form a unique fingerprint.

Cite this