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Published on: February 28, 2021
Vertebral microanatomy in squamates: structure, growth and ecological correlates
Alexandra Houssaye1, Arnaud Mazurier, Anthony Herrel
1UMR 7207 du CNRS, Département Histoire de la Terre, Muséum National d'Histoire Naturelle, Paris, France. houssaye@mnhn.fr
Journal of Anatomy
|November 3, 2010
Summary
Squamate vertebrae exhibit a unique tubular bone structure due to extensive bone remodeling. This distinct internal structure, differing from other tetrapods, shows a significant phylogenetic signal, particularly between snakes and lizards.
Area of Science:
- Comparative anatomy
- Vertebrate paleontology
- Histology
Background:
- Squamate vertebrae possess a unique internal structure distinct from other tetrapods.
- This structure is characterized by two concentric osseous tubes connected by trabeculae, resembling tubular bone.
Purpose of the Study:
- To investigate the internal vertebral structure of extant squamates.
- To understand the bone remodeling processes shaping this structure.
- To explore potential correlations between vertebral density, habitat, and phylogenetic relationships.
Main Methods:
- Histological examination of squamate vertebrae.
- Analysis of bone resorption and redeposition patterns.
- Comparative analysis of vertebral density across different taxa and habitats.
- Phylogenetic analyses to assess evolutionary signals.
Main Results:
- Squamate vertebrae display a unique, lightly built structure with two osseous tubes and few trabeculae, resulting from imbalanced bone remodeling.
- Vertebral growth is asymmetrical, with faster growth in the posterior centrum.
- Preliminary habitat-based density differences were not supported by phylogenetically informed analyses, indicating a strong phylogenetic signal.
- Snakes generally exhibit denser vertebrae than lizards, potentially explaining the observed phylogenetic signal.
Conclusions:
- The distinct internal vertebral structure in squamates is a result of a unique, prolonged bone remodeling process.
- Phylogenetic history, particularly the snake-lizard distinction, significantly influences vertebral density.
- Further research with broader sampling of aquatic and fossorial lizards is needed to clarify habitat-related patterns.
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