Pecora

Abstract: This paper presents the first complete estimate of the phylogenetic relationships among all 197 species of extant and recently extinct ruminants combining morphological, ethological and molecular information. The composite tree is derived by applying matrix representation using parsimony analysis to 164 previous partial estimates, and is remarkably well resolved, containing 159 nodes (>80% of the potential nodes in the completely resolved phylogeny). Bremer decay index has been used to indicate the degree of certainty associated with each clade. The ages of over 80 % of the clades in the tree have been estimated from information in the literature. The supertree for Ruminantia illustrates which areas of ruminant phylogeny are still only roughly known because of taxa with controversial relationships (e.g. Odocoileini, Antilopinae) or not studied in great detail (e.g. Muntiacus). It supports the monophyly of the ruminant families and Pecora. According to this analysis Antilocapridae and Giraffidae constitute the superfamily Giraffoidea, which is the sister group of a clade clustering Bovoidea and Cervoidea. The position of several taxa whose systematic positions have remained controversial in the past (Saiga, Pelea, Aepycerus, Pantholops, Ammotragus, Pseudois) is unambiguously established. Nevertheless, the position of Neotragus and Oreotragus within the original radiation of the non-bovine bovids remains unresolved in the present analysis. It also shows that six successive rapid cladogenesis events occurred within the infraorder Pecora during the Oligocene to middle Pliocene, which coincided with periods of global climatic change. Finally, the presented supertree will be a useful framework for comparative and evolutionary biologists interested in studies involving the ruminants.

Abstract: The ruminants constitute the largest group of ungulates, with >190 species, and its distribution is widespread throughout all continents except Australia and Antarctica. Six families are traditionally recognized within the suborder Ruminantia: Antilocapridae (pronghorns), Bovidae (cattle, sheep, and antelopes), Cervidae (deer), Giraffidae (giraffes and okapis), Moschidae (musk deer), and Tragulidae (chevrotains). The interrelationships of the families have been an area of controversy among morphology, palaeontology, and molecular studies, and almost all possible evolutionary scenarios have been proposed in the literature. We analyzed a large DNA data set (5,322 nucleotides) for 23 species including both mito- chondrial (cytochrome b, 12S ribosomal RNA (rRNA), and 16S rRNA) and nuclear (•-casein, cytochrome P-450, lactoferrin, andfi-lactalbumin) markers. Our results show that the family Tragulidae occupies a basal position with respect to all other ruminant families, confirming the traditional view that separates Tragulina and Pecora. Within the pecorans, Antilocapridae and Giraffidae emerge first, and the families Bovidae, Moschidae, and Cervidae are allied, with the unexpected placement of Moschus close to bovids rather than to cervids. We used these molecular results to assess the homoplastic evolution of morphological characters within the Ruminantia. A Bayesian relaxed molecular clock approach based on the continuous autocorrelation of evolutionary rates along branches was applied to estimate the divergence ages between the major clades of ruminants. The evolutionary radiation of Pecora occurred at the Early/Late Oligocene transition, and Pecoran families diversified and dispersed rapidly during the Early and Middle Miocene. We propose a biogeographic scenario to explain the extraordinary expansion of this group during the Cenozoic era. (Bayesian relaxed clock; Bovidae; molecules; morphology; Moschidae; phylogeny; Ruminantia.)

Abstract: Nine additional sequences from representatives of different tribes of the family Bovidae were combined with six published artiodactyl sequences to provide orthologous mtDNA for investigation of bovid phylogeny and evolution. Each species was represented by a homologous 2.7-kilobase-pair stretch of mtDNA for the complete 12S and 16S rRNA genes and three adjacent tRNA genes. These data, when compared to other results, provided evidence for a monophyletic Bovidae and for two clades within the family: one including the tribes Boselaphini, Bovini, and Tragelaphini and another for an Antilopini/Neotragini grouping. All other intrafamilial relationships were only weakly supported. These sequence comparisons suggest that most bovid tribes originated early in the Miocene with all extant lineages present by approximately 16-17 million years ago. Thus, bovid tribes provide an example of rapid cladogenesis, following the origin of families in the infraorder Pecora.

Abstract: We sequenced 2.7 kilobase pairs of contiguous coding mitochondrial DNA from Antilocarpia americana (Antilocapridae), Capra hircus (Bovidae), and Tragulus napu (Tragulidae) and compared these to previously pusblished orthologues for other ruminant species. Phylogenetic analysis of these sequences provided no robust patterns of relationship for the four families of pecoran ruminants studied. This finding is consistent with the hypothesis that the pecoran families resulted from a rapid radiation in the Early Miocene to Late Oligocene