Abstract
Skeletal simplification occurred in multiple vertebrate clades over the last 500 million years, including the evolution from premammalian cynodonts to mammals. This transition is characterised by the loss and reduction of cranial bones, the emergence of a novel jaw joint, and the rearrangement of the jaw musculature. These modifications have long been hypothesised to increase skull strength and efficiency during feeding. Here, we combine digital reconstruction and biomechanical modelling to show that there is no evidence for an increase in cranial strength and biomechanical performance. Our analyses demonstrate the selective functional reorganisation of the cranial skeleton, leading to reduced stresses in the braincase and the skull roof but increased stresses in the zygomatic region through this transition. This cranial functional reorganisation, reduction in mechanical advantage, and overall miniaturisation in body size are linked with a dietary specialisation to insectivory, permitting the subsequent morphological and ecological diversification of the mammalian lineage.
| Original language | English |
|---|---|
| Article number | 367 |
| Journal | Communications Biology |
| Volume | 6 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Dec 2023 |
Bibliographical note
Funding Information:We thank P. Brewer, S. Chapman (NHM, London), O. Rauhut, G. Rössner (BSPG, Munich), K. Angielczyk and W. Simpson (FMNH, Chicago), G. Hantke and A. Kitchener (NMS, Edinburgh) for access to specimens in their care. T. Rowe and J. Maisano (University of Texas, Austin) generously provided digital datasets of specimens. A.I. Neander (University of Chicago), G. Rössner (BSPG, Munich), D. Sykes (NHM, London), K. Robson Brown (University of Bristol), O. Katsamenis and M. Mavrogordato (University of Southampton) assisted with CT scanning. J.A. Hopson (University of Chicago) is thanked for the discussion. This work was funded by NERC grants NE/K01496X/1 (to E.J.R.) and NE/K013831/1 (to M.J.F.).
Funding Information:
We thank P. Brewer, S. Chapman (NHM, London), O. Rauhut, G. Rössner (BSPG, Munich), K. Angielczyk and W. Simpson (FMNH, Chicago), G. Hantke and A. Kitchener (NMS, Edinburgh) for access to specimens in their care. T. Rowe and J. Maisano (University of Texas, Austin) generously provided digital datasets of specimens. A.I. Neander (University of Chicago), G. Rössner (BSPG, Munich), D. Sykes (NHM, London), K. Robson Brown (University of Bristol), O. Katsamenis and M. Mavrogordato (University of Southampton) assisted with CT scanning. J.A. Hopson (University of Chicago) is thanked for the discussion. This work was funded by NERC grants NE/K01496X/1 (to E.J.R.) and NE/K013831/1 (to M.J.F.).
Publisher Copyright:
© 2023, The Author(s).