The anatomy of the head muscles in caecilians (Amphibia: Gymnophiona): Variation in relation to phylogeny and ecology?

Autor: Lowie A; Ghent University, Department of Biology, Evolutionary Morphology of Vertebrates, Ghent, Belgium., De Kegel B; Ghent University, Department of Biology, Evolutionary Morphology of Vertebrates, Ghent, Belgium., Wilkinson M; Department of Life Sciences, Natural History Museum, London, UK., Measey J; Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Stellenbosch, South Africa., O'Reilly JC; Department of Biomedical Sciences, Ohio University, Cleveland Campus, Cleveland, Ohio, USA., Kley NJ; Department of Anatomical Sciences, Health Sciences Center, Stony Brook University, Stony Brook, New York, USA., Gaucher P; USR 3456, CNRS, Centre de recherche de Montabo IRD, Cayenne, France., Adriaens D; Ghent University, Department of Biology, Evolutionary Morphology of Vertebrates, Ghent, Belgium., Herrel A; Ghent University, Department of Biology, Evolutionary Morphology of Vertebrates, Ghent, Belgium.; UMR 7179 C.N.R.S/M.N.H.N., Département d'Ecologie et de Gestion de la Biodiversité, Paris Cedex 5, France.
Jazyk: angličtina
Zdroj: Journal of anatomy [J Anat] 2023 Feb; Vol. 242 (2), pp. 312-326. Date of Electronic Publication: 2022 Sep 10.
DOI: 10.1111/joa.13763
Abstrakt: In limbless fossorial vertebrates such as caecilians (Gymnophiona), head-first burrowing imposes severe constraints on the morphology and overall size of the head. As such, caecilians developed a unique jaw-closing system involving the large and well-developed m. interhyoideus posterior, which is positioned in such a way that it does not significantly increase head diameter. Caecilians also possess unique muscles among amphibians. Understanding the diversity in the architecture and size of the cranial muscles may provide insights into how a typical amphibian system was adapted for a head-first burrowing lifestyle. In this study, we use dissection and non-destructive contrast-enhanced micro-computed tomography (μCT) scanning to describe and compare the cranial musculature of 13 species of caecilians. Our results show that the general organization of the head musculature is rather constant across extant caecilians. However, the early-diverging Rhinatrema bivittatum mainly relies on the 'ancestral' amphibian jaw-closing mechanism dominated by the m. adductores mandibulae, whereas other caecilians switched to the use of the derived dual jaw-closing mechanism involving the additional recruitment of the m. interhyoideus posterior. Additionally, the aquatic Typhlonectes show a greater investment in hyoid musculature than terrestrial caecilians, which is likely related to greater demands for ventilating their large lungs, and perhaps also an increased use of suction feeding. In addition to three-dimensional interactive models, our study provides the required quantitative data to permit the generation of accurate biomechanical models allowing the testing of further functional hypotheses.
(© 2022 Anatomical Society.)
Databáze: MEDLINE
Externí odkaz: