New anomalies and pathologies in the caudal region of the lizard’s axial skeleton

Abstract

Currently, more than 58 skeletal anomalies and pathologies are known in the recent Squamata reptiles. In this paper, eight pathologies of a complex nature are described in Agamidae and Lacertidae: Paralaudakia caucasia (Eichwald, 1831) and Lacerta agilis Linnaeus, 1758. Description of tail pathologies was carried out based on the analysis of X-ray images and on the results of computer microtomography. In the specimen of P. caucasia (ЗИН 19116.1) complete ablation of the caudal vertebra was revealed, which provoked the detachment of chevron and the proliferation of soft tissues. In some Agamidae, after pseudoautotomy, partial ablation of the caudal vertebra occurs to promote wound healing. Complete ablation of the distal caudal vertebra has not been previously reported in literature. In females of L. agilis, deformation of the right transverse process of the vertebra with “false bifurcation” without the formation of a cartilaginous tube (VOLSU 98.2), scoliosis, hematoma and callus on the cartilaginous tube were noted, as well as the absence of an autotomy plane in the postpygal vertebra (ZIN 31549). An unusual pathology in L. agilis (ZIN 31549) is the absence of an autotomy plane in the postpigal vertebra and of its anterior neural spine. The loss of the plane of autotomy during ontogeny is characteristic of some Iguanidae, but it has not been previously noted in Lacertidae. The described cases of anomalies expand the spectrum of known pathologies in reptiles.