Morphology and phylogenetic significance of the pelvic articular region in elasmobranchs (Chondrichthyes)

Author(s)

da Silva, Joao Paulo C. B. ; Vaz, Diego F. B.

• Document type: Journal article
• Source: CLADISTICS; v. N/A, p. 43-pg., 2023-03-01.

Abstract

The morphology of paired fins is commonly overlooked in morphological studies, particularly the pelvic girdle and fins. Consequently, previous phylogenetic studies incorporating morphological data used few skeletal characters from this complex. In this paper, the phylogenetic significance of pelvic articular characters for elasmobranchs is discussed in light of the morphological variation observed in 130 species, the most comprehensive study exploring the morphology of the pelvic girdle done so far. The 10 morphological characters proposed herein for the pelvic articulation were incorporated into a molecular matrix of NADH2 sequences and submitted to an analysis of maximum parsimony employing extended implied weighting. The most stable tree was selected based on the distortion coefficients, SPR distances (subtree pruning and regrafting) and fit values. Some of the striking synapomorphies recovered within elasmobranchs include the presence of an articular surface for the first enlarged pelvic radial supporting Elasmobranchii and the pelvic articular region for the basipterygium extending from the posterolatral margin of the pelvic girdle over its lateral surface in Echinorhinus + Hexanchiformes. Additionally, the proposed characters and their distributions are discussed considering the relationships recovered and also compared with previous morphological and molecular phylogenetic hypotheses. (AU)

• FAPESP's process: 12/22692-9 - Analysis of the skeletal pattern of paired fins and their respective GIRDLES in species of Chondrichthyes restricted to international collections
• Grantee: João Paulo Capretz Batista da Silva
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 12/07712-3 - Morphological and taxonomic review of the genus Centroscymnus Barboza du Bocage & Capello 1864 (Chondrichthyes:Squaliformes:Somniosidae)
• Grantee: Diego Francisco Biston Vaz
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 13/13137-4 - Morphological and taxonomic review of genus Centroscymnus Barboza du Bocage & Capello 1864 (Chondrichthyes: Squaliformes: Somniosidae)
• Grantee: Diego Francisco Biston Vaz
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree