The present is (not necessarily) the key to the past: exploring the systematics, biogeography, and diversification of the amphisbaenians (Reptilia: Squamata)

Résumé fourni par la source

Abstract Extant Amphisbaenia are distributed across Africa, the Americas, the Middle East, and the Mediterranean. Because of their fossorial habits, amphisbaenian biogeography was traditionally explained by vicariance. However, recent DNA studies emphasize the importance of transoceanic dispersal. Here, we provide the first phylogenomic analysis of Amphisbaenia using high-throughput sequence data (390 loci) with a comprehensive taxon sample. We present a time-calibrated phylogeny to infer biogeographic history and identify key cladogenetic events shaping present-day amphisbaenian diversity and distribution. Additionally, we evaluate head shape evolution and its association with speciation rates. We revise the group’s classification and present morphological diagnoses for some lineages, leading us to describe two new families and two new subfamilies from Africa. We also propose one new family from Cuba and one new subfamily from the Caribbean, and resurrect the subfamily Leposterninae and the genera Phractogonus and Typhloblanus. Our phylogeny suggests divergence between amphisbaenians and their sister-group lacertids occurred at ∼120 Mya, followed by early divergence of Rhineuridae from remaining amphisbaenians at ∼111 Mya. Considering their distinct skull morphologies, the round-headed shape is inferred to be ancestral for all high-level groups. The shovel-headed shape appeared more recently and is linked to the highest evolutionary rates, suggesting it enabled rapid speciation and habitat dispersal.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.