Anatomy

Postcrania

Theropoda

Sauropoda

Biology

Cretaceous

Phalanx

Paleontology

Taxon

Journal of Vertebrate Paleontology

ABSTRACT Recent collecting efforts (1993 to present) in the Upper Cretaceous (Maastrichtian) Maevarano Formation of northwestern Madagascar have yielded numerous specimens of the medium-sized abelisauroid theropod Majungasaurus crenatissimus (Depéret, 1896) Lavocat, 1955. Exquisite preservation, coupled with near-complete articulated or associated skeletons, has allowed an assessment of individual skeletal variation in this taxon, including a preliminary analysis of osteopathology in a non-tetanuran theropod. Importantly, Majungasaurus is the first abelisauroid theropod for which comprehensive pathology data are available. In a survey of 181 postcranial skeletal elements from a minimum of 21 individuals, abnormalities were identified in eight elements from a minimum of four individuals. These include a pedal phalanx with a mediolateral diaphyseal expansion of unknown etiology, a dorsal vertebra with a small exostosis, a caudal vertebra with probable idiopathic ossification of vertebral ligaments, and a pathologically truncated series of distal caudal vertebrae. The latter occurrence represents the first identified caudal truncation in a predatory dinosaur and only the second documented occurrence among non-avian dinosaurs.

PATHOLOGY IN<i>MAJUNGASAURUS CRENATISSIMUS</i>(THEROPODA: ABELISAURIDAE) FROM THE LATE CRETACEOUS OF MADAGASCAR

PATHOLOGY INMAJUNGASAURUS CRENATISSIMUS(THEROPODA: ABELISAURIDAE) FROM THE LATE CRETACEOUS OF MADAGASCAR