Usefulness of postpygal caudal vertebrae and osteoderms for skeletochronology in the limbless lizard Anguis veronensis Pollini, 1818 (Squamata: Sauria: anguidae).

In this study the authors tested the usefulness of postpygal caudal vertebra and osteoderms for the assessment of individual age in the limbless lizard Anguis veronensis POLLINI 1818, employing skeletochronological method. The results showed that osteoderm-based skeletochronology was unreliable since within any specimen examined the number of lines of arrested growth (LAG) varies between different osteoderms, and even within osteoderms. On the contrary, the skeletocronology was to some degree applicable to the neural arch of the caudal vertebra, as the LAG number was roughly stable in all neural arch per animal studied. Assuming that one LAG is formed per year, the oldest individual in the present study was 9 years old. However, age underestimation due to bone remodeling that completely destroyed the LAGs cannot be ruled out. Therefore, caution interpretation is required in the skeletochronological age estimation of Anguis if caudal vertebrae are analyzed.