Palatal morphology predicts the paleobiology of early salamanders
- University of Calgary, Canada
- George Washington University, United States
- Peking University, China
Abstract
Ecological preferences and life history strategies have enormous impacts on the evolution and phenotypic diversity of salamanders, but the yet established reliable ecological indicators from bony skeletons hinder investigations into the paleobiology of early salamanders. Here we statistically demonstrate, by using time-calibrated cladograms and geometric morphometric analysis on 71 specimens in 36 species, that both the shape of the palate and many non-shape covariates particularly associated with vomerine teeth are ecologically informative in early stem- and basal crown-group salamanders. Disparity patterns within the morphospace of the palate in ecological preferences, life history strategies and taxonomic affiliations were analyzed in detail, and evolutionary rates and ancestral states of the palate were reconstructed. Our results show that the palate is heavily impacted by convergence constrained by feeding mechanisms and also exhibits clear stepwise evolutionary patterns with alternative phenotypic configurations to cope with similar functional demand. Salamanders are diversified ecologically before the Middle Jurassic and achieved all their present ecological preferences in the Early Cretaceous. Our results reveal that the last common ancestor of all salamanders shares with other modern amphibians a unified biphasic ecological preference, and metamorphosis is significant in the expansion of ecomorphospace of the palate in early salamanders.
Data availability
All data needed to evaluate the conclusions are included in the manuscript and the Supplementary file 1. Details of specimens, CT parameters and raw landmark coordinates and centroid sizes are available in three CSV files in the online Dryad repository (https://doi.org/10.5061/dryad.c59zw3r8x). Source codes for R and SAS used in this study is available at GitHub (https://github.com/PaleoSalaman).
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Specimen list and landmark coordinates for the palate of early salamandersDryad Digital Repository, doi:10.5061/dryad.c59zw3r8x.
Article and author information
Author details
Funding
National Natural Science Foundation of China (41702002)
- Jia Jia
National Natural Science Foundation of China (41872008)
- Ke-Qin Gao
State Key Laboratory of Palaeobiology and Stratigraphy (193111)
- Jia Jia
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Min Zhu, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, China
Version history
- Received: January 7, 2022
- Preprint posted: January 17, 2022 (view preprint)
- Accepted: May 15, 2022
- Accepted Manuscript published: May 16, 2022 (version 1)
- Version of Record published: June 6, 2022 (version 2)
Copyright
© 2022, Jia et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Palatal morphology predicts the paleobiology of early salamanders
eLife 11:e76864.
https://doi.org/10.7554/eLife.76864
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