UNRAVELING THE JAWS: COMPARATIVE ANATOMY AND PHYLOGENETIC IMPLICATIONS OF THE MANDIBULAR ARCH FOR ELASMOBRANCHS (Chondrichthyes: Elasmobranchii)

• Grant number: 24/16174-2
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: July 01, 2025
• End date: April 30, 2029
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Otto Bismarck Fazzano Gadig
• Grantee: Jade Medeiros de França Cardoso
• Host Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil

Abstract

The class Chondrichthyes represents an ancient and successful group of cartilaginous fish that have evolved distinctive skeletal modifications since the Paleozoic era. Despite advances in molecular studies, the phylogenetic relationships among elasmobranchs remain unresolved, with conflicting hypotheses arising from both morphological and genetic data. Given the crucial role of jaw morphology in feeding strategies and in the ecological and evolutionary success of these fishes, understanding the evolution of these skeletal features is essential. This project aims to thoroughly describe and illustrate the mandibular arch (palatoquadrate and Meckel's cartilage) across various Chondrichthyes families, documenting the variation to identify new, phylogenetically informative skeletal characters. These findings will contribute to resolving ongoing debates, such as the monophyly of sharks and the phylogenetic positioning of rays, offering fresh insights into the evolutionary history of this diverse and ancient group.