Osteoderms as calcium reservoirs: Insights from the lizard Ouroborus cataphractus. Issue 3 (3rd May 2022)

• Record Type: Journal Article
• Authors: Broeckhoven, Chris; du Plessis, Anton
• Is Part Of: Journal of anatomy. Volume 241:Issue 3(2022)
• Page Start: 635
• Page End: 640
• Publication Date: 2022-05-03
• Subjects: bone mineral density -- bone resorption -- dermal bone -- micro‐computed tomography -- osteoclast -- reproduction -- sexual dimorphism; Anatomy -- Periodicals; 571.3
• DOI: 10.1111/joa.13683
• Languages: English
• ISSNs: 0021-8782

Abstract

Abstract: The functional significance of osteoderms—bony elements embedded in the dermis—remains a topic of much debate. Although many hypotheses have been put forward in the past, the idea that osteoderms can serve as calcium reservoirs has received little experimental attention thus far. In this study, we use micro‐computed tomography to investigate inter‐ and intrasexual variation in osteoderm density in the viviparous lizard Ouroborus cataphractus and conduct histochemical analyses to unravel the potential mechanism involved in mineral resorption from the osteoderms. Our results show that females have denser, more compact osteoderms than males of similar body sizes, regardless of the season during which they were collected and their reproductive state. Furthermore, a histochemical study demonstrates the presence of mononucleated TRAP‐positive cells in the vascular canals of the osteoderms. Based on the findings of this study, we suggest that the mineral storage hypothesis merits further attention as a candidate explanation for osteoderm evolution. Abstract : "The hypothesis that osteoderms can serve as calcium reservoirs has received little attention in past studies. Using density‐calibrated micro‐computed tomography, we demonstrate that female Armadillo lizards ( Ouroborus cataphractus ) have denser, more compact osteoderms than males of similar body sizes. Furthermore, a histochemical study reveales mononucleated TRAP‐positive cells in the vascular canals of the osteoderms."