A pathological Late Pleistocene canid from San Sidero (Italy): implications for social- and feeding-behaviour

Multiple cranial pathologies in spotted hyaenas, Crocuta crocuta

Spotted hyaenas are generally considered to have resilience against injuries and pathogens, and the incidence of pathologies is scarcely reported. However, it is important for ecological studies and conservation efforts to have a clear overview of the physical threats that can occur in the life of a species. The present paper describes and interprets several osteopathologies in the crania of the spotted hyaena, Crocuta crocuta, in the collections of the Royal Museum for Central Africa (RMCA) in Tervuren, Belgium. Of the fifty-two specimens from central Africa examined, twenty-three (i.e., 44 %) of them showed evidence of pathologies, including injuries, congenital pathologies, and disease. Selected specimens were scanned using Computed Tomography and their internal cranial structures were studied. Here we describe and discuss the different types of pathologies evident in the crania of these hyaenas: craniosynostosis, microtia, osteomyelitis and periodontitis, as well as a trauma indicated by cranial fractures, dental fractures, and bite puncture marks. Some pathologies reported herein are novel for hyaenas, and there are some instances of multiple pathologies in the same individual. Implications of these pathologies, including the social interactions of hyenas, conservational threats, as well as biased data sampling, are highlighted. This study improves our knowledge of disease and trauma experienced by hyaenids, and provides a better understanding of their biology, and the potential threats faced by these iconic animals. This case study offers a comparative base for similar studies in other carnivorans, to clarify the pathological background of apex predators.

Computed tomography reveals hip dysplasia in the extinct Pleistocene saber-tooth cat Smilodon

Reconstructing the behavior of extinct species is challenging, particularly for those with no living analogues. However, damage preserved as paleopathologies on bone can record how an animal moved in life, potentially reflecting behavioral patterns. Here, we assess hypothesized etiologies of pathology in a pelvis and associated right femur of a Smilodon fatalis saber-toothed cat, one of the best-studied species from the Pleistocene-age Rancho La Brea asphalt seeps, California, USA, using visualization by computed tomography (CT). The pelvis exhibits massive destruction of the right hip socket that was interpreted, for nearly a century, to have developed from trauma and infection. CT imaging reveals instead that the pathological distortions characterize chronic remodeling that began at birth and led to degeneration of the joint over the animal's life. These results suggest that this individual suffered from hip dysplasia, a congenital condition common in domestic dogs and cats. This individual reached adulthood but could not have hunted properly nor defended territory on its own, likely relying on a social group for feeding and protection. While extant social felids are rare, these fossils and others with similar pathologies are consistent with a spectrum of social strategies in Smilodon supported by a predominance of previous studies.

Synchrotron radiation reveals the identity of the large felid from Monte Argentario (Early Pleistocene, Italy)

We describe here a partial skull with associated mandible of a large felid from Monte Argentario, Italy (Early Pleistocene; ~1.5 million years). Propagation x-ray phase-contrast synchrotron microtomography of the specimen, still partially embedded in the rock matrix, allows ascribing it reliably to Acinonyx pardinensis, one of the most intriguing extinct carnivorans of the Old World Plio-Pleistocene. The analysis of images and 3D models obtained through synchrotron microtomography – here applied for the first time on a Plio-Pleistocene carnivoran – reveals a mosaic of cheetah-like and Panthera-like features, with the latter justifying previous attributions of the fossil to the extinct Eurasian jaguar Panthera gombaszoegensis. Similarly, we reassign to A. pardinensis some other Italian materials previously referred to P. gombaszoegensis (sites of Pietrafitta and Ellera di Corciano). The recognition of Panthera-like characters in A. pardinensis leads to reconsidering the ecological role of this species, whose hunting strategy was likely to be different from those of the living cheetah. Furthermore, we hypothesise that the high intraspecific variation in body size in A. pardinensis can be the result of sexual dimorphism, as observed today in all large-sized felids.