New stegosaurian (Ornithischia, Thyreophora) remains from Jurassic-Cretaceous transition beds of Valencia province (Southwestern Iberian Range, Spain)

J. Company,J.I. Ruiz-omeñaca,X. Pereda Suberbiola

doi:10.5209/rev_jige.2010.v36.n2.10

Abstract

New stegosaurian remains have been recently recovered from the Jurassic-Cretaceous transition sandstones of the Villar del Arzobispo Formation (Tithonian-Berriasian) in the Valencia province, eastern Spain. Specimens consist of two partially articulated (or closely associated) postcranial skeletons. The Baldovar specimen is composed of appendicular bones (scapula, femur) and two pairs of dermal tail spines, two of them articulated with two distal caudal vertebrae. The second specimen, unearthed in the vicinity of La Yesa village, consists of dorsal vertebrae and ribs, fragments of caudal centra and an incomplete femur. The new specimens are tentatively referred to the clade Dacentrurinae and may belong to Dacentrurus on the basis of features observed on the dorsal vertebrae and caudal dermal spines. Stegosaurs are represented so far in the Jurassic-Cretaceous transition of Spain by Dacentrurus. The presence of other taxa (Stegosaurus, Miragaia) in Spain, recently documented in the Late Jurassic of Portugal, cannot be attested on the basis of the currently recorded material.

Highlights

Omosaurus armatus, from the Early Kimmeridgian of Wiltshire (England), was the first articulated stegosaur described in the world and is the type species of Dacentrurus
The Spanish fossils have been referred to Dacentrurus based mainly on the presence of cervical ribs fused to respective vertebrae and/or dorsal vertebrae provided with wider than longer centra, features considered at present as synapomorphies of the clade Dacentrurinae (Mateus et al, 2009)
In this paper we describe preliminarily new stegosaurian material from the Tithonian-Berriasian Villar del Arzobispo Formation cropping out near the villages of La Yesa and Baldovar (Valencia province, eastern Spain)

Summary

Introduction

From the Early Kimmeridgian of Wiltshire (England), was the first articulated stegosaur described in the world and is the type species of Dacentrurus. The Spanish fossils have been referred to Dacentrurus based mainly on the presence of cervical ribs fused to respective vertebrae and/or dorsal vertebrae provided with wider than longer centra, features considered at present as synapomorphies of the clade Dacentrurinae (Mateus et al, 2009). These materials should be restudied in order to clarify its referral to Dacentrurus, Miragaia or to another undefined dacentrurine (RuizOmeñaca et al, 2009). In this paper we describe preliminarily new stegosaurian material from the Tithonian-Berriasian Villar del Arzobispo Formation cropping out near the villages of La Yesa and Baldovar (Valencia province, eastern Spain). History Museum, London, UK; MCNV, Museo de Ciencias Naturales de Valencia, Spain; MPA, Museo Paleontológico de Alpuente, Valencia province, Spain; YPM: Yale Peabody Museum, New Haven, USA

Location and Geological setting

El Balsón specimen

Discussion

Barranco del Curro specimen

Conclusions