First evidence of convergent lifestyle signal in reptile skull roof microanatomy
Abstract Background The study of convergently acquired adaptations allows fundamental insight into life’s evolutionary history. Within lepidosaur reptiles—i.e. lizards, tuatara, and snakes—a fully fossorial (‘burrowing’) lifestyle has independently evolved in most major clades. However, despite thei...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2020-11-01
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| Series: | BMC Biology |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12915-020-00908-y |
| _version_ | 1818432801433714688 |
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| author | Roy Ebel Johannes Müller Till Ramm Christy Hipsley Eli Amson |
| author_facet | Roy Ebel Johannes Müller Till Ramm Christy Hipsley Eli Amson |
| author_sort | Roy Ebel |
| collection | DOAJ |
| description | Abstract Background The study of convergently acquired adaptations allows fundamental insight into life’s evolutionary history. Within lepidosaur reptiles—i.e. lizards, tuatara, and snakes—a fully fossorial (‘burrowing’) lifestyle has independently evolved in most major clades. However, despite their consistent use of the skull as a digging tool, cranial modifications common to all these lineages are yet to be found. In particular, bone microanatomy, although highly diagnostic for lifestyle, remains unexplored in the lepidosaur cranium. This constitutes a key gap in our understanding of their complexly interwoven ecology, morphology, and evolution. In order to bridge this gap, we reconstructed the acquisition of a fossorial lifestyle in 2813 lepidosaurs and assessed the skull roof compactness from microCT cross-sections in a representative subset (n = 99). We tested this and five macroscopic morphological traits for their convergent evolution. Results We found that fossoriality evolved independently in 54 lepidosaur lineages. Furthermore, a highly compact skull roof, small skull diameter, elongate cranium, and low length ratio of frontal and parietal were repeatedly acquired in concert with a fossorial lifestyle. Conclusions We report a novel case of convergence that concerns lepidosaur diversity as a whole. Our findings further indicate an early evolution of fossorial modifications in the amphisbaenian ‘worm-lizards’ and support a fossorial origin for snakes. Nonetheless, our results suggest distinct evolutionary pathways between fossorial lizards and snakes through different contingencies. We thus provide novel insights into the evolutionary mechanisms and constraints underlying amniote diversity and a powerful tool for the reconstruction of extinct reptile ecology. |
| first_indexed | 2024-12-14T16:10:58Z |
| format | Article |
| id | doaj.art-b67245dcc3c44e7e8a59413142d6e5e4 |
| institution | Directory Open Access Journal |
| issn | 1741-7007 |
| language | English |
| last_indexed | 2024-12-14T16:10:58Z |
| publishDate | 2020-11-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Biology |
| spelling | doaj.art-b67245dcc3c44e7e8a59413142d6e5e42022-12-21T22:55:00ZengBMCBMC Biology1741-70072020-11-0118111810.1186/s12915-020-00908-yFirst evidence of convergent lifestyle signal in reptile skull roof microanatomyRoy Ebel0Johannes Müller1Till Ramm2Christy Hipsley3Eli Amson4Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity ScienceMuseum für Naturkunde, Leibniz Institute for Evolution and Biodiversity ScienceMuseum für Naturkunde, Leibniz Institute for Evolution and Biodiversity ScienceSchool of BioSciences, The University of MelbourneMuseum für Naturkunde, Leibniz Institute for Evolution and Biodiversity ScienceAbstract Background The study of convergently acquired adaptations allows fundamental insight into life’s evolutionary history. Within lepidosaur reptiles—i.e. lizards, tuatara, and snakes—a fully fossorial (‘burrowing’) lifestyle has independently evolved in most major clades. However, despite their consistent use of the skull as a digging tool, cranial modifications common to all these lineages are yet to be found. In particular, bone microanatomy, although highly diagnostic for lifestyle, remains unexplored in the lepidosaur cranium. This constitutes a key gap in our understanding of their complexly interwoven ecology, morphology, and evolution. In order to bridge this gap, we reconstructed the acquisition of a fossorial lifestyle in 2813 lepidosaurs and assessed the skull roof compactness from microCT cross-sections in a representative subset (n = 99). We tested this and five macroscopic morphological traits for their convergent evolution. Results We found that fossoriality evolved independently in 54 lepidosaur lineages. Furthermore, a highly compact skull roof, small skull diameter, elongate cranium, and low length ratio of frontal and parietal were repeatedly acquired in concert with a fossorial lifestyle. Conclusions We report a novel case of convergence that concerns lepidosaur diversity as a whole. Our findings further indicate an early evolution of fossorial modifications in the amphisbaenian ‘worm-lizards’ and support a fossorial origin for snakes. Nonetheless, our results suggest distinct evolutionary pathways between fossorial lizards and snakes through different contingencies. We thus provide novel insights into the evolutionary mechanisms and constraints underlying amniote diversity and a powerful tool for the reconstruction of extinct reptile ecology.https://doi.org/10.1186/s12915-020-00908-yConvergent evolutionBoneMicroanatomySkull roofFossorialLepidosaur |
| spellingShingle | Roy Ebel Johannes Müller Till Ramm Christy Hipsley Eli Amson First evidence of convergent lifestyle signal in reptile skull roof microanatomy BMC Biology Convergent evolution Bone Microanatomy Skull roof Fossorial Lepidosaur |
| title | First evidence of convergent lifestyle signal in reptile skull roof microanatomy |
| title_full | First evidence of convergent lifestyle signal in reptile skull roof microanatomy |
| title_fullStr | First evidence of convergent lifestyle signal in reptile skull roof microanatomy |
| title_full_unstemmed | First evidence of convergent lifestyle signal in reptile skull roof microanatomy |
| title_short | First evidence of convergent lifestyle signal in reptile skull roof microanatomy |
| title_sort | first evidence of convergent lifestyle signal in reptile skull roof microanatomy |
| topic | Convergent evolution Bone Microanatomy Skull roof Fossorial Lepidosaur |
| url | https://doi.org/10.1186/s12915-020-00908-y |
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