An Oxfordian Ichthyosauria (Reptilia) from Viñales, western Cuba: paleobiogeographic significance

Abstract

FIGURE 1. Map showing locaties near Vinales (Western Cuba) where Jurassic marine reptiles were found (simplified after Iturralde-Vinent and Norell, 1996). Black strips: main outcrops of the middle–late Oxfordian Jagua Formation. 1, ‘‘near Vinales’’; 2, Puerta del Ancon; 3, Laguna de Piedra; 4, Vinales town. Western Cuba has yielded significant material of Jurassic marine reptiles since very early in this century, when the Cuban naturalist Don Carlos de la Torre y Huerta discovered the first specimens from the area of Vinales (Alvarez Conde, 1957) (Fig. 1). It was some time before the fossil reptiles were partially described (R. De la Torre and Cuervo, 1939; R. De la Torre and Rojas, 1949; A. De la Torre, 1949; Colbert, 1969). The presence of ‘‘ichthyosaur remains’’ within this assemblage was first reported by R. De la Torre and Cuervo (1939) who described two new taxa: Sphaerodontes caroli and Ichthyosaurus torrei, but neither are now considered valid as the first was based on a fish, and the second has been reindentified as a plesiosaur (Iturralde-Vinent and Norell, 1996). In a later paper, R. De la Torre and Rojas (1949) described one species and two subspecies of ‘‘ichthyosaurs’’ but they refered the taxa to Cryptocleidus, a plesiosauroid genus. In fact, none of these species or subspecies are referable to Ichthyosauria (Iturralde-Vinent and Norell, 1996). Recently, a synopsis of the provenance and identity of Jurassic marine reptiles from Cuba has been published by IturraldeVinent and Norell (1996). In this paper, many of the early taxonomic designations have been revised, but no ichthyosaur remains could be identified. Some of the Jurassic fossil remains of marine reptiles from Cuba have been sent on loan to the Departamento de Paleontologia de Vertebrados of the Museo de la Plata (Argentina), as part of a joint research project between the Argentinian institution and the Cuban Museo Nacional de Historia Natural in Havana. Among these materials there is a specimen (MNHNH-P 3068) embedded in black limestone which, before preparation, was characterized by Iturralde-Vinent and Norell (1996) as a skull fragment of a large marine reptile composed of a few bone fragments surrounding extremely large scleral ossicles. According to these authors it represented the largest saurian specimen yet recovered from the Jurassic of Cuba. Further preparation of MNHNH-P 3068 at the Museo de la Plata allowed the identification of the skull bones preserved, among which there is the basioccipital that is of important taxonomic interest. With these elements the specimen can now be identified as an ichthyosaurian of the Ophthalmosauria (sensu Motani, 1999). This is the first Ichthyosaur properly identified from Cuba. The scope of the present paper is to describe the new specimen and analyze its paleobiogeographical significance. Abbreviations—MNHNH-P, Paleontological Collection of the Cuban Museo Nacional de Historia Natural.