Abstract

I use the well-corroborated tree of living vertebrates to measure the phylogenetic value of data typically used in paleontology: bones and teeth. In particular, I ask if the loss of non-fossilizable data causes taxa to occur in misleadingly basal positions. Adding morphology to DNA data sets usually increases congruence of resulting topologies to the well-corroborated tree, but this varies among morphological data sets. Extant taxa with a high proportion of missing morphological characters can greatly reduce phylogenetic resolution when analyzed together with fossils. While loss of data can lead to misleadingly basal positions for fossils, there is no evidence that is more frequent than other kinds of phylogenetic error. Morphology comprises the evidence held in common by living taxa and fossils, and phylogenetic analysis of fossils greatly benefits from inclusion of molecular and morphological data sampled for living taxa, whatever methods are used for phylogeny estimation.