Anatomy, Morphometry and Radiography in the thoracic limb bones of the Patagonian Huemul Deer (Hippocamelus bisulcus)

Anatomy and computed tomography of the nasal cavity, nasal conchae, and paranasal sinuses of the endangered Patagonian huemul deer (Hippocamelus bisulcus)

This study explores for the first time the shape, volume, and configuration of nasal cavity structures of the endangered Patagonian huemul deer via computed tomography (CT). Three-dimensional (3D) reconstructions derived from data sets obtained from five Patagonian huemul deer skulls were analyzed. Using semiautomatic segmentation, 3D models were created of all the sinus compartments and nasal conchae. Volumetric measurements were taken of seven sinus compartments. The Patagonian huemul deer has a wide, large nasal cavity, with an osseous nasal aperture typical of cervids and a choana with characteristics that differentiate it from the pudu and roe deer. It also has six nasal meatuses and three nasal conchae, with the ventral nasal concha having the greatest volume and surface, which given its extension ensures a greater ability to humidify and heat the air. Further analysis showed the complex system of paranasal sinuses to be characterized by a rostroventral and interconnected group, where communication with the nasal cavity is common through the nasomaxillary opening, and a caudodorsal group that communicates with the nasal cavity through openings in the nasal meatuses. Our study of the endangered Patagonian huemul deer documents an intricate, and in some nasal cavity structures, unique morphological construction which may predispose it to higher rates of sinonasal afflictions due largely to its nasal complex anatomy, thus affecting its high cultural value.

Skull anatomy of the endangered Patagonian huemul deer(Hippocamelus bisulcus)

Studies of the normal skull anatomy of the Patagonian Huemul deer are scarce. Currently, the findings of bone lesions in the skull associated with metabolic imbalances are frequent in the literature. The objective of this study was to provide anatomical and morphometric data of the cranium and facies including a morphofunctional interpretation as a reference for clinical, ecomorphological and educational purposes. Five skulls were described, measured, scanned and digitally reconstructed. The presence of a caudal projection of the vomer bone, the absence of the facial tubercle and thin bones forming the cranial cavity were observed. Linear measurements allowed the skull to be classified as dolichocephalic, hyperlepten and ultra-dolichocranial. In conclusion, the Patagonian Huemul has a long head, an extremely long skull and a very narrow face. The thickness of the bones that made up the walls of the cranial cavity suggests chronic metabolic imbalances in response to mineral deficiency. The anatomical and morphometric data obtained in this study strongly emphasizes the relevance of considering the implementation of such management policies that aim at promoting an optimal nutritional context.

Functional limb anatomy in a refugee species: The endangered Patagonian huemul deer (Hippocamelus bisulcus)

Early naturalists already considered huemul rare, refuged and a stocky, short-legged mountain deer, 163 years before declared endangered (1972). Anatomically, huemul do not overlap with rock-climbers previously considered analogous, as corroborated in this paper by including additional huemul cases. Assertions that population declines are caused principally via livestock infections remain unfounded. Instead, osteopathology in multiple populations across 1,000 km, affecting 57% among dead and 86% among live specimens, may relate to micronutrient deficiencies. Historically classified a mountain deer, widespread osteopathology, micronutrient deficiencies and lack of recovery qualify huemul as a refugee species. Recovery strategies thus must include repopulating historical distribution sites.