Distributions of extinction times from fossil ages and tree topologies: the example of some mid-Permian synapsid extinctions

Gilles Didier (1) , Michel Laurin (2)

1 IMAG - Institut Montpelliérain Alexander Grothendieck
2 CR2P - Centre de Recherche en Paléontologie - Paris

Given a phylogenetic tree of extinct and extant taxa with fossils where the only temporal information stands in the fossil ages, we devise a method to compute the distribution of the extinction time of a given set of taxa under the Fossilized-Birth-Death model. Our approach differs from the previous ones in that it takes into account the possibility that the taxa or the clade considered may diversify before going extinct, whilst previous methods just rely on the fossil recovery rate to estimate confidence intervals. We assess and compare our new approach with a standard previous one using simulated data. Results show that our method provides more accurate confidence intervals. This new approach is applied to the study of the extinction time of three Permo-Carboniferous synapsid taxa (Ophiacodontidae, Edaphosauridae, and Sphenacodontidae) that are thought to have disappeared toward the end of the Cisuralian, or possibly shortly thereafter. The timing of extinctions of these three taxa and of their component lineages supports the idea that a biological crisis occurred in the late Kungurian/early Roadian.

Domaines: Evolution [q-bio.PE]

Gilles Didier, Michel Laurin. Distributions of extinction times from fossil ages and tree topologies: the example of some mid-Permian synapsid extinctions. 2021. ⟨hal-03258099v1⟩