Total Evidence Phylogenetic Analysis Supports New Morphological Synapomorphies for Bovidae (Mammalia, Artiodactyla)

Abstract

Advances in gene sequencing technology have made it easier to generate large molecular datasets with novel DNA sequences for phylogenetic analysis. Because morphological data are difficult to collect and not required for molecular phylogenetic analyses, they are often excluded in studies of the systematic relationships of extant taxa. This fact is especially apparent in the Bovidae, the highly diverse, widespread clade of hoofed mammals most often characterized by the presence of permanent bony horn cores covered with keratin sheaths. Analyses of molecular data have reconstructed well-supported phylogenetic relationships within the clade. However, morphological data are also required to integrate fossil taxa into these studies, and may support different topologies when they are included in total evidence phylogenies. In this study, I performed a maximum likelihood phylogenetic analysis of a total evidence dataset including mitochondrial genomes, nine nuclear genes, and 196 morphological characters. The dataset comprises 156 species, 13 of which are fossil taxa, one of the most complete analyses of the family to date, and the first time many of the fossil species have been included in a total evidence analysis. Character optimizations on this topology produced seven synapomorphic morphological characters for Bovidae and multiple characters for each tribe. These analyses support the use of total evidence phylogenetics as a means of uncovering morphological characters that may serve as new synapomorphies and elucidate the systematic relationships of fossil species.