In the jaws of a titan: the jaws of giant canary lizards under study

In the Canary Islands there are currently only four species of giant lizards that belong to the sex roosterbut between 2.6 million years and 800,000 years ago a fifth species inhabited, goliath rooster, as revealed by the fossil record of the islands. With the arrival of the first humans to the Canary Islands, around 2,500 years ago, a drastic process of extinction began, which was accentuated with the colonization of Europeans around 600 years ago, as it meant the mass entry of catsdogs and herbivores that decimated populations of giant lizards.

Despite numerous studies on the biological aspects of this endemic insular genus whose current species are in danger of extinction, little is known about its anatomy.

Now, a study describes and compares the bones that make up the jaws of these giant lizards of the Canary Islands. leaning on x-ray microtomography Performed on different specimens, 3D models of the jaws were created, which allowed the analysis of the different bones while maintaining their anatomical layout. These models will allow in the future to carry out computational biomechanical studies to deepen the food ecology of these lizards.

The multidisciplinary team composed of members of the research groups Study of the Fossil and Current Fauna of the Canary Islands at the University of La Laguna, as well as Aragosaurus-IUCA from the University of Zaragoza, the Catalan Institute of Paleontology Miquel Crusafont, the National Council for Scientific Research and Técnicas (Argentina) and ICTP – International Center for Theoretical Physics of Trieste (Italy) analyzed jaws of the five species included in the genus rooster.

“Knowing in detail the anatomy of the jaws of the different current and extinct species of giant lizards will allow us to more accurately identify the species to which the remains we found belong, something essential to understand the evolution of this genus over time”, explains Sara Perez Martin, the researcher responsible for the study. The data obtained will also allow the analysis of differences between individuals of the same species due, for example, to ontogeny, that is, to their stage of development.

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3D models of the species. /PCI

Five species of giant lizard

The study includes the first osteological descriptions of the jaw of the Giant Lizard of La Gomera (gallotia bravoana) and the Tenerife Giant Lizard (Intermediate Galotia). The study carried out is fundamental not only to understand the evolution of this genus over time, but also to know its distribution and migratory patterns, data that are very necessary for the management of the preservation of current populations. The research was published in the international scientific journal Historical Biology.

The five giant species recorded by the genus rooster In order of sizes they are: goliath rooster, fossil species from the islands of Tenerife and El Hierro and the largest of them all; and the living species: Gran Canaria Giant Lizard (Gallotia Stehlini); Giant Iron Lizard (gallotia simonyi); Giant Lizard of La Gomera (bravoan galoty); and Tenerife Giant Lizard (Intermediate Galotia).