Dental paleopathology in fossil rhinoceroses: etiology and implications

Abstract

The identification and interpretation of paleopathological findings in the dentition of mammals have the potential to shed light on disturbed development and stress conditions. In combination with knowledge about the timing of dental development, dental pathologies can provide a unique opportunity to reconstruct specific phases in the life history of fossil taxa, as well as animal-environment interactions. The dental ontogeny of the extinct rhinoceros Prosantorhinus germanicus from the Miocene is well-known from an exceptionally preserved sample of juvenile dentaries. Two of the represented juvenile individuals each revealed a dental anomaly, which were analyzed macroscopically and via X-ray tomography in this study. One specimen documents decreased dental wear of deciduous cheek teeth, mandibular bone resorption as well as abnormal cemental deposition. At an early age, the extinct juvenile rhinoceros probably was affected by a gingival infection resulting from an accumulation of bacterial plaque. This led to a chronic gingivitis and eventually may have caused periodontitis. Furthermore, it suffered from inflammation-induced hypercementosis. Another specimen revealed an abnormal reduction in thickness of enamel in the deciduous cheek tooth. The enamel hypoplasia indicates stress experienced during the prenatal period. During a phase of environmental stress (e.g. increased fluoride exposure) or physiological stress (e.g. malnutrition) the function of the secretory ameloblasts was disrupted in the developing embryo. The present work shows that the analysis of dental paleopathologies is a useful means for retrospective assessment of specific phases in the life history of extinct animals. This adds to the picture of the living conditions of the extinct rhinoceros P. germanicus.

A Model for Dental Age Verification Using Ultrastructural Imaging for Modern and Fossil Representatives of the Rhinocerotidae Family

“…For the examined tooth, histological characterization of its dental structures was undertaken, and on the occlusal surface areas and points of the anatomical build of the crown were identified, according to the terminology recommended by Fortelius [ 36 ], Prat [ 37 ], Antoine et al [ 38 ], and Böhmer et al [ 39 ] ( Figure 4 ).…”

“…During this process of preparation and preservation, of the mandible mandibula, a photographic documentation was made (Figure 2) together with an X-ray in lateral projection (Figure 3). For the examined tooth, histological characterization of its dental structures was undertaken, and on the occlusal surface areas and points of the anatomical build of the crown For the examined tooth, histological characterization of its dental structures was undertaken, and on the occlusal surface areas and points of the anatomical build of the crown were identified, according to the terminology recommended by Fortelius [36], Prat [37], Antoine et al [38], and Böhmer et al [39] (Figure 4).…”

“…were identified, according to the terminology recommended by Fortelius [36], Prat [3 Antoine et al [38], and Böhmer et al [39] ( Figure 4).…”

Dientes Fósiles de Carcharocles megalodon : La Colección del Museo Universitario de Chieti (Italia). Parte II: Análisis Paleopatológico

“…ej. : Capasso & D'Anastasio, 2001;D'Anastasio et al, 2002;Böhmer & Rössner, 2018). En el caso de los condrictios (Chondrichthyes), también conocidos como peces cartilaginosos, entre los que recordamos especies vivas como tiburones, rayas y mantarrayas, y especies extintas como el tiburón megalodonte, los dientes constituyen casi exclusivamente el registro fósil conservado de esta clase de vertebrados acuáticos, precisamente a causa de la naturaleza cartilaginosa de su esqueleto.…”

Mini‐series: palaeopathology – a fresh look at ancient diseases in the fossil record

“…concerning the interaction between individual animals and populations with their (changing) environment. This topic is addressed in the contribution of Böhmer & Rösner () that presents pathologies in the deciduous teeth of two juvenile Miocene rhinoceroses. One of the reported pathologies, a reduction in thickness of enamel (linear enamel hypoplasia) indicates that the animal underwent a phase of stress.…”