A new sauropod dinosaur from the Middle Jurassic of the United Kingdom.

Phillip L Manning,Mike Romano,Victoria M Egerton,Anthony Fiorillo

doi:10.1371/journal.pone.0128107

Abstract

A new record of a sauropodomorph dinosaur is here described from the Middle Jurassic (Aalenian) Saltwick Formation of Whitby (Yorkshire), UK. A single caudal vertebra represents an early sauropodomorph and signifies the earliest recognised eusauropod dinosaur from the United Kingdom. The absence of pleurocoels and a narrow, dorsoventrally deep, but craniocaudally short centrum, suggests a primitive sauropodomorph. Distinct spinopostzygopophyseal laminae rise from the lateral margins of the postzygapophyses and pass caudally along what remains of the neural spine, a character unique to a subgroup of sauropods that includes Barapasaurus, Omeisaurus and other neosauropods and eusauropods. The lack of phylogenetically robust characters in sauropod caudal vertebrae usually makes it difficult to establish affinities, but the absence of mild procoely excludes this specimen from both Diplodocoidea and Lithostrotia. The vertebra cannot be further distinguished from those of a wide range of basal sauropods, cetiosaurids and basal macronarians. However, this plesiomorphic vertebra still signifies the earliest stratigraphic occurrence for a British sauropod dinosaur.

Highlights

The fossil remains of Middle Jurassic sauropods are extremely rare [1]
The collection of vertebrate and invertebrate fossil remains from below the mean high-tide mark are only restricted in a handful of localities in the UK (e.g. Lyme Regis, Jurassic Coast World Heritage site where local by-laws protect vertebrate fossils), that does not include the site in the current study
The pronounced ventral keel is unique to this sauropod and contrasts with the midline groove that occurs on the anterior caudals of basal sauropods such as Vulcanodon, Cetiosaurus, Omeisaurus, and Haplocanthosaurus, as well as from derived sauropod clades [1]

Summary

Introduction

The fossil remains of Middle Jurassic sauropods are extremely rare [1]. The major finds of Middle Jurassic sauropods are in China (Shunosaurus [2], Omeisaurus [3], Mamenchisaurus [4]), Argentina (Patagosaurus [5]), North Africa (Spinophorosaurus [6], and Jobaria [7]).) and Britain (Cetiosaurus [8]).The Middle Jurassic in northeast England has yielded only a few dinosaur bones from the rocks of undoubted Middle Jurassic age [9]. The fossil remains of Middle Jurassic sauropods are extremely rare [1]. The major finds of Middle Jurassic sauropods are in China (Shunosaurus [2], Omeisaurus [3], Mamenchisaurus [4]), Argentina (Patagosaurus [5]), North Africa (Spinophorosaurus [6], and Jobaria [7]).) and Britain (Cetiosaurus [8]). The Middle Jurassic in northeast England has yielded only a few dinosaur bones from the rocks of undoubted Middle Jurassic age [9]. Distal podial elements and vertebral centra were recovered from the Scarborough Formation at White Nab, Scarborough Bay [8,10,11]. The Scarborough Formation is a marine unit within the mainly terrestrial deposits of the Ravenscar Group. Neither publication included illustrations and only included the measurements of the centrum: eight inches craniocaudally long and nine inches wide [13]

Methods

Discussion

Conclusion