INTERSPECIFIC VARIATION AMONG CANARY GIANT LIZARDS (Gallotia) BASED ON X-RAY MICROCOMPUTED TOMOGRAPHY OF THE MANDIBLE

SARA PÉREZ-MARTÍN; JOSEP FORTUNY; CAROLINA CASTILLO RUIZ; PENÉLOPE CRUZADO CABALLERO

Congreso; 2nd Palaeontological Virtual Congress; 2020

The genus Gallotia includes omnivorous lizards of small to giant size, all of them endemic to theCanary Islands. There are six giant species, four of them extant (G. simonyi, G. stehlini, G. bravoanaand G. intermedia) and two extinct (G. goliath and G. auaritae). They are distributed naturallythroughout all the islands of the archipelago except Lanzarote and Fuerteventura (in the latter, G. stehlini was introduced by human activity). The species extinctions were most probablycaused by anthropic action, and three of the extant species (all except G. stehlini) are seriouslythreatened. In this work, mandibles belonging to the six extant and fossil giant lizard speciesfrom the Canary Islands are studied. X-ray microcomputed tomography is performed, generatinghigh-resolution 3D models of each mandibular bone. A morphological description and detailedosteological comparison has been undertaken. The main objective is to establish key featuresand characters in order to clarify the taxonomy of the Gallotia species. Potential interspecific diagnostic features have been identified, such as the form and direction of the retroarticular process, the presence/absence of an S-shaped crest in the coronoid and the degree of fusion between the surangular and the articulate, among others. The data obtained are the first step towards combining paleontological and biological information to perform phylogenetic analyses as well as (paleo-)ecological studies and to assess their implications for the management and conservation of the canary giant lizards.