Project aims

Osteoderms are bony elements that are expressed in the skin of a few disparate groups of tetrapods (in crocodiles, turtles, armadillos, and some lizard and frog species) – but not in other taxa. In humans, osteoderms are frequent complications of injury and symptomatic of a few rare inherited disorders. 

Osteoderms spark interest because they are ecologically relevant (they are likely to function in body protection, thermoregulation and water budget maintenance, in mineral storage) but at the same time exhibit an unusually binary distribution (i.e., they are expressed completely, or not at all). The latter element facilitates research into the genomic substrate of the trait. 

One species of cordylid lizard, Hemicordylus capensis, uniquely displays intraspecific variation in osteoderms: the trait has evolved repeatedly and therefore is present in some populations, but not in others. The species thus offers exceptional opportunities for learning how, why and when this remarkable trait evolves. 

Hemicordylus capensis

With this project, we aim to resolve those issues through a thoroughly integrated approach combining state-of-the-art genomicfunctional morphological and ecological techniques. We will also explore if we can extrapolate the findings on this study system to other taxa that (occasionally) express osteoderms, including humans. The project will allow a rare complete view of the evolution of an ecologically relevant phenotypic characteristic with a remarkably discontinuous variation and an unusually disparate taxonomic distribution.

Project team

In order to get to the bottom of the osteoderm issue, researchers from different backgrounds have joined forces. 

Interested in joining the team? We are currently looking for two PhD students! Follow the links below.