The fossil record of camelids demonstrates a late divergence between Bactrian camel and dromedary

Denis Geraads (1) , Gilles Didier (2) , Andrew Barr (3) , Denné Reed (4) , Michel Laurin (1)

1 CR2P - Centre de Recherche en Paléontologie - Paris
2 IMAG - Institut Montpelliérain Alexander Grothendieck
3 GU - Georgetown University [Washington]
4 University of Texas at Austin [Austin]

A new compilation of the Old World fossil record of the Camelidae and a recent phylogenetic analysis allow a new assessment of the timing of the diversification in that taxon. Using a recent implementation of the fossilized birth-death process, we show that the divergence between Bactrian camel and dromedary has a peak probability density around 1 Ma and probably occurred less than 2 million years ago. These dates are much younger than molecular estimates, which place the divergence between the dromedary and the Bactrian camel between 4 and 8 million years ago. Calibration problems in molecular dating seems to explain much of this difference.

Mots clés: Mammalia; Camelidae; phylogeny; Pleistocene; divergence time; fossil record; birth-and-death models; Africa

Domaines: Paléontologie; Evolution [q-bio.PE]

Denis Geraads, Gilles Didier, Andrew Barr, Denné Reed, Michel Laurin. The fossil record of camelids demonstrates a late divergence between Bactrian camel and dromedary. Acta Palaeontologica Polonica, 2020, 65 (2), pp.251-260. ⟨10.4202/app.00727.2020⟩. ⟨hal-02895911⟩