Scythes, sickles and other blades: defining the diversity of pectoral fin morphotypes in Pachycormiformes

Authors

Jeff J. Liston, SNSB-Bayerische Staatssammlung für Paläontologie und Geologie
Anthony E. Maltese, Rocky Mountain Dinosaur Resource Center
Paul H. Lambers, Utrecht University
Dominique Delsate, Musée National d’histoire Naturelle de Luxembourg
William E.H. Harcourt-Smith, CUNY Lehman CollegeFollow
Anneke H. van Heteren, Staatliche Naturwissenschaftliche Sammlungen Bayerns

Document Type

Article

Publication Date

11-7-2019

Abstract

The traditional terminology of ‘scythe’ or ‘sickle’ shaped is observed to be flawed as an effective descriptor for pectoral fin shape in pachycormids. The diversity of pachycormid pectoral fin shapes is assessed across the 14 recognised genera that preserve complete pectoral fins, and improved terms are defined to more effectively describe their form, supported by anatomical observation and aspect ratio analysis of individual fins, and corroborated by landmark analysis. Three clear and distinct pectoral fin structural morphotypes emerge (falceform, gladiform, falcataform), reflecting a diversity of pachycormid lifestyles throughout the Mesozoic, from agile pursuit predator to slow-cruising suspension feeder.

Comments

This work was originally published in PeerJ, available at http://dx.doi.org/10.7717/peerj.7675

This article is distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).