How Common Are Lesions on the Tails of Sauropods? Two New Pathologies in Titanosaurs from the Late Cretaceous of Argentine Patagonia

Abstract

Studies of the paleopathology of the vertebrae provide an interesting, oblique approach to their paleobiology and even paleoethology. They tell us about possible ethological causes such as accidental blows with objects, social interactions within a group, and defense against predators, etc. There are numerous works on the anatomical and phylogenetic aspects of sauropod dinosaurs, and in recent years paleopathological studies have also increased. Here, we describe the injuries recorded in the caudal vertebrae of two indeterminate titanosaurids, and undertake a compilation and analysis of the pathological fossil record worldwide, focusing on the tails of sauropods. Two pathologies have been identified as present in the indeterminate titanosaurids under study: a possible case of spondyloarthropathy in MAU-Pv-LI-601, and a case of suppurative spinal osteomyelitis in MAU-Pv-LJ-472/1. Both titanosaurids are from Gondwana. In the world registry of pathologies associated with the tails of sauropod dinosaurs, it is observed that titanosaurs are the sauropods with the highest percentage of diagnosed pathologies (69% including the two new records from the province of Neuquén) and that all of these have been described in Gondwanan specimens.

New information on paleopathologies in non-avian theropod dinosaurs: a case study on South American abelisaurids

“…It is recovered in 3.5% of the sample, and only in Allosaurus fragilis and Elemgasem nubilus [ 45 , 74 ]. However, spondyloarthropathy is the most represented pathology along the caudal portion, an outcome in accordance with its record among sauropod dinosaurs [ 54 ]. The presence of congenital malformations is reported in almost 3% of the sample, being Aucasaurus the oldest record among non-avian theropods with this pathology so far.…”

“…In this work, we have carried out a macroscopic description of the pathological bones for each specimen and use the paleohistology and alternatively CT-scan to assess the modification of the internal microstructure and then to understand the response of the bones affected by maladies. So far, pathological specimens from South America were reported only among ornithopod, sauropodomorph, and tetanuran dinosaurs [ 31 , 38 , 46 – 54 ], but none for non-tetanuran theropods. Here we present the first study on paleopathologies for the clade Brachyrostra (Theropoda, Ceratosauria), and at the same time the third one for the clade Abelisauridae after the works on Majungasaurus .…”