Abstract

Paleontological and neontological systematics seek to answer evolutionary questions with different datasets. Phylogenies and divergence times estimated from exclusively extant or inclusive extant and extinct taxa frequently conflict. Until recently, it was not possible to combine the data from paleontology and neontology to simultaneously estimate evolutionary relationships and divergence times. We used two methods to estimate the phylogeny and divergence times for living and fossil primates, the tip-dating (TD) and fossilized birth-death process (FBD). We collected new morphological data, especially focusing on the living and extinct endemic primates of Madagascar, the lemurs. We combined the morphological data with published DNA sequences to infer a near-complete (88% of lemurs) time-calibrated phylogenies. The results suggest that primates originated around the Cretaceous-Tertiary boundary, slightly earlier than indicated by the fossil record and later than previously inferred from molecular data alone. We infer both novel relationships among extinct lemurs, and strong support for relationships that were previously unresolved. Dates inferred with TD were significantly earlier than those inferred with FBD and estimates with FBD were consistent under different fossil date priors. This is the first study to combine morphological and DNA sequence data from extinct and extant primates to infer evolutionary relationships and divergence times, and our results shed light on questions of primate evolution that could not be addressed before.