SSU ribosomal sequences of trypanosomes from Brazilian cattle and water buffalo were used to infer phylogenetic relationships between non-pathogenic T. theileri and allied species parasitic in artiodactyls. T. theileri trypanosomes from distinct geographical regions in Brazil and from other countries were tightly clustered into the ‘clade T. theileri’ distant from the ‘T. brucei clade’ of pathogenic parasites of artiodactyls, and also distinct from trypanosomes of other mammals. The existence of this monophyletic assemblage (T. theileri clade) composed only by isolates from artiodactyl species justifies the continued recognition of the subgenus T. (Megatrypanum) with T. theileri as its type species. Phylogenies based on SSU and ITS1 ribosomal sequences produced the same branching pattern with isolates from different mammalian hosts clustered in 5 lineages: A, related to water buffalo; B, C and D, to cattle; E, to fallow deer. The pattern of host specificity allied to some congruence between host and parasite phylogenies suggested association of these trypanosomes with their respective hosts. Segregation of cattle isolates into three lineages revealed an overall geographical structure. Moreover, positioning of trypanosomes infecting tabanids in the T. theileri clade is consistent with the role of these flies as important vectors of these trypanosomes.

Despite the biological and economic importance of the Cetartiodactyla, the phylogeny of this clade remains controversial. Using the supertree approach of matrix representation with parsimony, we present the first phylogeny to include all 290 extant species of the Cetacea (whales and dolphins) and Artiodactyla (even-toed hoofed mammals). At the family-level, the supertree is fully resolved. For example, the relationships among the Ruminantia appear as (((Cervidae, Moschidae) Bovidae) (Giraffidae, Antilocapridae) Tragulidae). However, due to either lack of phylogenetic study or contradictory information, polytomies occur within the clades Sus, Muntiacus, Cervus, Delphinidae, Ziphiidae and Bovidae. Complete species-level phylogenies are necessary for both illustrating and analysing biological, geographical and ecological patterns in an evolutionary framework. The present species-level tree of the Cetartiodactyla provides the first opportunity to examine comparative hypotheses across entirely aquatic and terrestrial species within a single mammalian order.

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.

Much of the narial anatomy of the enigmatic antelope Saiga tatarica has been described by previous workers. However, the anatomy of the nasal cavity and the causally associated osteological correlates of proboscis structure require closer attention, because these data are integral for both a more comprehensive understanding of saiga functional morphology and more robust reconstructions of proboscis structure in fossil taxa. Saiga and outgroup specimens were subjected to X-ray computed tomographic (CT) imaging, gross dissection and skeletonization. The nasal cavity of saiga is characterized by an enlarged nasal vestibule and basal conchal fold. Many structures (e.g. turbinates, lateral cartilages, mucosal folds, nasolacrimal duct) are retracted caudally to a small area in the caudodorsal part of the nasal cavity proper. The enlarged vestibule is associated laterally and ventrally with paired sacs. The nasal septum is largely membranous and contains a large patch of cavernous tissue that serves as a dynamic baffle modifying the flow of inspired air. Bones comprising the narial margin have modified attachment sites for buccinator group muscles and the reduced lateral cartilages. The premaxilla is greatly modified by the enlarged musculature associated with nasolabial fusion. Maintenance of the topological relationships of narial structures compared to bovid outgroups has resulted in a nasal cavity with much larger area for seromucous glands of the vestibule as well as narial musculature capable of controlling the aperture of the nasal cavity. Maxillolabial muscles and the lateralis nasi act together both to compress the nasal cavity and to control the dilation of the nostrils such that air flow through the cavity is highly modified relative to bovid outgroups. The lateral vestibular recess is an outpocketing of the nasal vestibule that produces supplementary seromucous secretions and seems to have no homologue among outgroups. The enlarged nasal vestibule, lateral vestibular recess, repositioned basal fold, and septal cavernous mass are regarded as a coordinated adaptation to dusty habitats, such that nasal air flow can be dynamically regulated allowing for collection of inspired particulates in the vestibule and thus cleansing of air destined for the lungs.

The facial region of moose Alces alces is highly divergent relative to other cervids and other ruminants. In particular, the narial region forms an expanded muzzle or proboscis that overhangs the mouth. The nose of moose provides a case study in the evolution of narial novelty within a phylogenetically well-resolved group (Cervidae). The function of the nasal apparatus of moose remains enigmatic, and new hypotheses are proposed based on our anatomical findings. Head specimens of moose and outgroup taxa were subjected to medical imaging (CT scanning), vascular injection, gross anatomical dissection, gross sectioning, and skeletonization. Moose noses are characterized by highly enlarged nostrils accompanied by specialized musculature, expanded nasal cartilages, and an increase in the connective-tissue pad serving as the termination of the alar fold. The nostrils are widely separated, and the rhinarium that encircles both nostrils in outgroups is reduced to a tiny central patch in moose. The dorsal lateral nasal cartilage is modified to form a pulley mechanism associated with the levator muscle of the upper lip. The lateral accessory nasal cartilage is enlarged and serves as an attachment site for musculature controlling the aperture of the nostril, particularly the lateralis nasi, the apical dilatators, and the rectus nasi. Bony support for narial structures is reduced. Moose show greatly enlarged nasal cartilages, and the entire osseocartilaginous apparatus is relatively much larger than in outgroups. The nasal vestibule of moose is very large and houses a system of three recesses: one rostral and one caudal to the nostrils, and one associated with the enlarged fibrofatty alar fold. As a result of the expanded nasal vestibule, osseous support for the nasal conchae (i.e. turbinates) has retracted caudally along with the bony nasal aperture. The nasoturbinate and its mucosal counterparts (dorsal nasal concha and rectal fold) are reduced. The upturned maxilloturbinate, however, is associated with an enlarged ventral nasal concha and alar fold. Moose are the only species of cervid with these particular characteristics, indicating that this anatomical configuration is indeed novel. Although functional hypotheses await testing, our anatomical findings and published behavioural observations suggest that the novel narial apparatus of moose probably has less to do with respiratory physiology than with functions pertaining specifically to the nostrils. The widely separated and laterally facing nostrils may enhance stereolfaction (i.e. extracting directional cues from gradients of odorant molecules in the environment), but other attributes of narial architecture (enlarged cartilages, specialized musculature, recesses, fibrofatty pads) suggest that this function may not have been the evolutionary driving force. Rather, these attributes suggest a mechanical function, namely, an elaborated nostril-closing system.

We studied movements of white-lipped peccaries (Tayassu pecari, Artiodactyla, Tayassuidae) throughout the Osa Peninsula and their use by local people during 1997–2000, using interview techniques. We draw five main conclusions: 1) White-lipped peccaries living on the Osa Peninsula range within Corcovado National Park for most of the year. 2) Peccaries travel beyond the Park boundaries to the north and south-east of the Peninsula at the end of the wet season when a fruit shortage occurs in Corcovado. 3) The local people hunt peccaries as the herds move through the Peninsula. 4) Current small herd sizes observed by locals in the Peninsula and by researchers in the Park may indicate a decline of the peccary population. 5) Peccaries constitute neither an important source of food nor a source of cash income for local people. We suggest that sustainable use of peccaries in this region is neither realistic nor necessary. Instead of trying to legalize and regulate hunting, effective systems to control illegal hunting should be implemented, especially outside the Park boundary from October to January when the animals are on the move.