Cocodrilos del Cretácico inferior de Galve (Teruel, España)

Abstract

The description of new material from the Lower Cretaceus of the Galve Syncline (province of Teruel, Spain) belonging to several outcrops, confirms the presence of the following Metamesosuchian crocodiles: Goniopholis, Thenosuchus and Bemissartia. These taxa had been identified based on isolated teeth (Estes & Sanchiz, 1982; Buscalioni & Sanz, 1984) and by means of a whole specimen Bemissartia (Buscalioni et al., 1984). The postcraneal remains coming from the outcrop called Rocha-Pelejón (RPAH) (unit 3/4, Díaz et al., 1984; Díaz & Yébenes, in this volume) have been identified as Mesosuchia indel. Proximal and distal epiphyseal rests of stylopods and zeugopods compose the studied material. Morphological comparations between Mesosuchia and Eusuchia are also discused. A few features are proposed to be shared among some Mesosuchia, such as Trematochampsidae and Goniopholididae, that are not present in the Eusuchia. These characters are: lesser inclination, in those Mesosuchia, of the proximal end, lesser development of the proximal femoral end respect to the shaft; the presence of an anterior prominence in the proximal outline of the tibia and the humeral head with a marked steps like outline. The described craneal rest from Galve's outcrops, Cabezo Sta. Bárbara (CBP) (unit 5, Díaz et al., 1984) and Rocha-Pelejón (RPAH), are identified as cf. Goniopbolis sp. and Goniopbolis cf crassidens, respectively. The present apomorphies which are exposed as the presence of the character (considering Tecodonts Proterosuchia+Erythrosuchia as the out-group) are interpreted from the material available: a) hypapophises of the first dorsal centra; b) ventral scutes; e) exoccipitals getting the occipital condyle; d) a dorso-ventral ridge in the basioccipital along the sagital plane; e) basisphenoids hidden in palatal view; f) maxillary wall depth low and g) finally, maxillary festooning. These apomorphic character-states are shared with some Mesosuchia: Goniopholididae, Bemissartidae and Trematochampsidae. A phenetic comparation between the studied material and the Lower Cretaceous British specimens, belonging to Goniopbolis, shows that Galve exemplars are closer to Goniopholidids. 64 isolated vertebral centra found in most oC Galve's outcrops (Pelejón, PH, unit 3/4, Díaz et al., 1984; Colladico-Blanco, CBH, unit 4; Barranco Poyales-Cerrada Roya, PBCH, unit 511; Rocha-Pelejón, RPAH; Partida-Poyales, PYH, unit 5II; Cerrada Roya Mina, CR, unit 5I y Cabezo Sta. Bárbara fit well with the identifications that had been proposed with isolated teeth. Three diferent types of centra are described: procoelous and semi-procoelous which have been atributed to the Metamesosuchia Theriosuchus or/and Bemissartia. Anphicoelous are separated into several morphotypes. None of the features proposed seems to be significative, and perphaps either the appreciated diversity or variability could be supported in ontogenetical and/or individual factors.