Revalidation of Myobradypterygius hauthali Huene, 1927 and the phylogenetic signal within the ophthalmosaurid (Ichthyosauria) forefins

Abstract

In the last decade, several new Cretaceous ichthyosaurs have been described and/or redescribed, challenging the traditional concept that, during the Cretaceous, ichthyosaurs were abundant but not diverse. Here, we redescribe the holotype and referred specimen of ‘Platypterygius’ hauthali Huene (1927) from the Barremian of Argentinean Patagonia and compare its appendicular anatomy with that of a referred specimen from the Valanginian - Hauterivian of Chile. These specimens consist almost entirely of anterior appendicular elements, so we explore quantitatively the phylogenetic signal contained in the forefin of the ophthalmosaurids and include them in a new phylogenetic analysis. Our results support the revalidation of the genus Myobradypterygius Huene, 1927, for the reception of the materials previously assigned to ‘Pl.’ hauthali. Moreover, we found that forefin characters present a strong phylogenetic signal, highlighting the utility of these characters as a source of systematic information.