Research paper

A new estiracostern dinosaur (Ornithopoda: Ankylopollexia) from the Lower Cretaceous of Spain

C/ Almazán 17, 42004, Soria, Spain.
Corresponding author

C/ Almazán 17, 42004, Soria, Spain.

C/ Almazán 17, 42004, Soria, Spain.

C/ Almazán 17, 42004, Soria, Spain.


The Zorralbo I site from the Lower Cretaceous (upper Hauterivian/lower Barremian of the Golmayo Formation), located in Golmayo municipality (Soria, Spain), has yielded diverse material belonging to four types of dinosaurs: ornithopods, ankylosaurids (Polacanthus sp.), sauropods (Titanosauriform) and theropods (Allosauroidea and Dromaeosauridae), crocodiles (Goniopholis sp.) and an undetermined turtle. In this paper, we analyze the material belonging to a new iguanodontian dinosaur, a medium-sized quadrupedal specimen (9-10 m long) weighing three tonnes, that exhibits a number of morphological and biometric features that set it apart from already known iguanodontians: 1) the coronoid process is a prolongation of the dentary, being the last dental alveolus in front the coronoid process instead of at its base; 2) the length of the scapula is six times its distal width and seven times its minimum width; 3) the acromial process is facing the posterior protuberance; 4) in the humerus, the inner tuberosity is not aligned with the ulnar condyle and the radial condyle sits above the ulnar condyle; 5) in the ulna, the distal end is wider than the proximal end and it is mace-shaped; 6) in the radius, the distal end is also mace-shaped; 7) the carpus is made up of three components (carpals I, II and III, radiale and intermediale) (ulnare and carpal IV) (carpal V); 8) the phalangeal formula is 1-3-3-2- (3-4); the width of the wrist is equivalent to 70 % of the hand length; 9) straight prepubis without distal widening or grooves and in the base of the post-pubic ramus, the obturator foramen is open and semi-covered by a mesial flat bone plate. The combination of these features and the differences between this specimen and all other iguanodontian genera to which it has been compared lead to the conclusion that it is indeed a new genus within this dinosaur group. We propose the name Magnamanus soriaensis nov. gen. nov. sp.

Keywords: Magnamanus soriaensis, Iguanodontia, Lower Cretaceous, Iberian Range, Spain.

How to cite: Fuentes Vidarte, C., Meijide Calvo, M., Meijide Fuentes, F. & Meijide Fuentes, M. 2016. Un nuevo dinosaurio estiracosterno (Ornithopoda: Ankylopollexia) del Cretácico Inferior de España. [A new estiracostern dinosaur (Ornithopoda: Ankylopollexia) from the Lower Cretaceous of Spain]. Spanish Journal of Palaeontology, 31 (2), 407-446.

Received 12 May 2015, Accepted 6 August 2016, Published 31 December 2016

(Spanish only)