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Origin and higher-level diversification of snakes: basal key-taxa and the Colubroidean Cenozoic radiation (Squamata)

Grant number: 18/11902-9
Support type:Scholarships abroad - Research
Effective date (Start): October 13, 2018
Effective date (End): October 12, 2019
Field of knowledge:Biological Sciences - Zoology
Principal Investigator:Hussam El Dine Zaher
Grantee:Hussam El Dine Zaher
Host: Michel Laurin
Home Institution: Museu de Zoologia (MZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
Local de pesquisa : Muséum National d'Histoire Naturelle, France  

Abstract

The main objective of this project is to study the patterns related to the origin and diversification of snakes, using in an unprecedented way a large sample of recent and fossil taxa and combining morphological and molecular data in a total evidence approach. This research will be conducted at the Muséum National d'Histoire Naturelle de Paris, in close collaboration with Dr. Michel Laurin, supervisor of this project, e Dr. Nour-Eddine Jalil, curator of the Fossil Reptiles collection. I intend to address two key points in snake evolutionary history: 1) their still controversial origin in the Cretaceous, and 2) their diversification in the Cenozoic. In order to achieve these objectives, I intend to study in detail the available Mesozoic and Cenozoic fossil record, with an emphasis on fossil key-taxa of snakes and squamates. I also intend to include new fossil snakes that are being described and combine the morphological data with the phylogenomic results produced recently by our team. In addition, I intend to estimate the time of divergence of snake clades during the aforementioned time interval, using indirect methods of tree calibration ("node dating methods") and methods of total evidence ("tip dating methods"). This latter approach has considerably improved our knowledge of vertebrate origin and diversification, and more advanced methods of direct tree calibration have recently been developed by Dr. Laurin's team. These methods should improve our understanding of the evolution of snakes by allowing us to produce estimations of rates of diversification and fossilization by combining results derived from tree topologies with temporal intervals of the fossils included in these trees.