To discover interordinal relationships of living and fossil placental mammals and the time of origin of placentals relative to the Cretaceous-Paleogene (K-Pg) boundary, we scored 4541 phenomic characters de novo for 86 fossil and living species. Combining these data with molecular sequences, we obtained a phylogenetic tree that, when calibrated with fossils, shows that crown clade Placentalia and placental orders originated after the K-Pg boundary. Many nodes discovered using molecular data are upheld, but phenomic signals overturn molecular signals to show Sundatheria (Dermoptera + Scandentia) as the sister taxon of Primates, a close link between Proboscidea (elephants) and Sirenia (sea cows), and the monophyly of echolocating Chiroptera (bats). Our tree suggests that Placentalia first split into Xenarthra and Epitheria; extinct New World species are the oldest members of Afrotheria.

Bats (Chiroptera) represent one of the largest and most diverse radiations of mammals, accounting for one-fifth of extant species. Although recent studies unambiguously support bat monophyly and consensus is rapidly emerging about evolutionary relationships among extant lineages, the fossil record of bats extends over 50 million years, and early evolution of the group remains poorly understood. Here we describe a new bat from the Early Eocene Green River Formation of Wyoming, USA, with features that are more primitive than seen in any previously known bat. The evolutionary pathways that led to flapping flight and echolocation in bats have been in dispute, and until now fossils have been of limited use in documenting transitions involved in this marked change in lifestyle. Phylogenetically informed comparisons of the new taxon with other bats and non-flying mammals reveal that critical morphological and functional changes evolved incrementally. Forelimb anatomy indicates that the new bat was capable of powered flight like other Eocene bats, but ear morphology suggests that it lacked their echolocation abilities, supporting a 'flight first' hypothesis for chiropteran evolution. The shape of the wings suggests that an undulating gliding-fluttering flight style may be primitive for bats, and the presence of a long calcar indicates that a broad tail membrane evolved early in Chiroptera, probably functioning as an additional airfoil rather than as a prey-capture device. Limb proportions and retention of claws on all digits indicate that the new bat may have been an agile climber that employed quadrupedal locomotion and under-branch hanging behaviour.

We present the first estimate of the phylogenetic relationships among all 916 extant and nine recently extinct species of bats Mammalia: Chiroptera), a group that accounts for almost one-quarter of extant mammalian diversity. This phylogeny was derived by combining 105 estimates of bat phylogenetic relationships published since 1970 using the supertree construction technique of Matrix Representation with Parsimony (MRP). Despite the explosive growth in the number of phylogenetic studies of bats since 1990, phylogenetic relationships in the order have been studied non-randomly. For example, over one-third of all bat systematic studies to date have locused on relationships within Phyllostomidae, whereas relationships within clades such as Kerivoulinae and Murinae have never been studied using cladistic methods. Resolution in the supertree similarly differs among clades: overall resolution is poor (46.4%, of a fully bifurcating solution) but reaches 100% in some groups (e.g. relationships within Mormoopidae). The supertree analysis does not support a recent proposal that Microchiroptera is paraphyletic with respect to Megachiroptera, as the majority of source topologies support microbat monophyly. Although it is not a substitute for comprehensive phylogenetic analyses of primary molecular and morphological data, the bat supertree provides a useful tool for future phylogenetic comparative and macroevolutionary studies. Additionally, it identifies clades that have been little studied, highlights groups within which relationships are controversial, and like all phylogenetic studies, provides preliminary hypotheses that can form starting points for future phylogenetic studies of bats.

The phylogenetic and geographic origins of bats (Chiroptera) remain unknown. The earliest confirmed records of bats date from the early Eocene (approximately 51 Ma) in North America with other early Eocene bat taxa also being represented from Europe, Africa, and Australia. Where known, skeletons of these early taxa indicate that many of the anatomical specializations characteristic of bats had already been achieved by the early Eocene, including forelimb and manus elongation in conjunction with structural changes in the pectoral skeleton, hind limb reorientation, and the presence of rudimentary echolocating abilities. By the middle Eocene, the diversification of bats was well underway with many modern families being represented among fossil forms. A new phylogenetic analysis indicates that several early fossil bats are consecutive sister taxa to the extant crown group (including megabats), and suggests a single origin for the order, at least by the late Paleocene. Although morphological studies have long placed bats in the Grandorder Archonta, (along with primates dermopterans, and tree shrews), recent molecular studies have refuted this hypothesis, instead strongly supporting placement of bats in Laurasiatheria. Primitively, proto-bats were likely insectivorous, under-branch hangers and elementary gliders that exploited terminal branch habitats. Recent work has indicated that a number of other mammalian groups began to exploit similar arboreal, terminal branch habitats in the Paleocene, including multituberculates, eulipotyphlans, dermopterans, and plesiadapiforms. This may offer an ecological explanation for morphological convergences that led to the erroneous inclusion of bats within Archonta: ancestral archontan groups as well as proto-bats apparently were exploiting similar arboreal habitats, which may have led to concurrent development of homoplasic morphological attributes.

Explanations for rapid species' range expansions have typically been purely ecological, with little attention given to evolutionary processes. We tested predictions for the evolution of dispersal during range expansion using four species of wing-dimorphic bush cricket (Conocephalus discolor, Conocephalus dorsalis, Metrioptera roeselii, and Metrioptera brachyptera). We observed distinct changes in dispersal in the two species with expanding ranges. Recently colonized populations at the range margin showed increased frequencies of dispersive, long-winged (macropterous) individuals, compared with longer-established populations in the range core. This increase in dispersal appeared to be short-lived because 5-10 years after colonization populations showed similar incidences of macroptery to populations in the range core. These changes are consistent with evolutionary change; field patterns persisted when nymphs were reared under controlled environmental conditions, and range margin individuals reared in the laboratory flew farther than range core individuals in a wind tunnel. There was also a reproductive trade-off with dispersal in both females and males, which could explain the rapid reversion to lower rates of dispersal once populations become established. The effect of population density on wing morphology differed between populations from the range core (no significant effect of density) and expanding range margins (negative density dependence), which we propose is part of the mechanism of the changes in dispersal. Transient changes in dispersal are likely to be common in many species undergoing range expansion and can have major population and biogeographic consequences.

Beetle horns are enlarged outgrowths of the head or thorax that are used as weapons in contests over access to mates. Horn development is typically confined to males (sexual dimorphism) and often only to the largest males (male dimorphism). Both types of dimorphism result from endocrine threshold mechanisms that coordinate cell proliferation near the end of the larval period. Here, we map the presence/absence of each type of dimorphism onto a recent phylogeny for the genus Onthophagus (Coleoptera: Scarabaeidae) to explore how horn development has changed over time. Our results provide empirical support for several recent predictions regarding the evolutionary lability of developmental thresholds, including uncoupled evolution of alternative phenotypes and repeated fixation of phenotypes. We also report striking evidence of a possible developmental constraint. We show that male dimorphism and sexual dimorphism map together on the phylogeny; whenever small males have horns, females also have horns (and vice versa). We raise the possibility that correlated evolution of these two phenomena results from a shared element in their endocrine regulatory mechanisms rather than a history of common selection pressures. These results illustrate the type of insight that can be gained only from the integration of developmental and evolutionary perspectives.

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Pteropodidae is a diverse Old World family of non-echolocating, frugivorous and nectarivorous bats that includes the flying foxes (genus Pteropus) and allied genera. The subfamily Pteropodinae includes the largest living bats and is distributed across an immense geographic range from islands in East Africa to the Cook Islands of Polynesia. These bats are keystone species in their ecosystems and some carry zoonotic diseases that are increasingly a focus of interest in biomedical research. Here we present a comprehensive phylogeny for pteropodines focused on Pteropus. The analyses included 50 of the ∼63 species of Pteropus and 11 species from 7 related genera. We obtained sequences of the cytochrome b and the 12S rRNA mitochondrial genes for all species and sequences of the nuclear RAG1, vWF, and BRCA1 genes for a subsample of taxa. Some of the sequences of Pteropus were obtained from skin biopsies of museum specimens including that of an extinct species, P. tokudae. The resulting trees recovered Pteropus as monophyletic, although further work is needed to determine whether P. personatus belongs in the genus. Monophyly of the majority of traditionally-recognized Pteropus species groups was rejected, but statistical support was strong for several clades on which we based a new classification of the Pteropus species into 13 species groups. Other noteworthy results emerged regarding species status of several problematic taxa, including recognition of P. capistratus and P. ennisae as distinct species, paraphyly of the P. hypomelanus complex, and conspecific status of P. pelewensis pelewensis and P. p. yapensis. Relationships among the pteropodine genera were not completely resolved with the current dataset. Divergence time analysis suggests that Pteropus originated in the Miocene and that two independent bursts of diversification occurred in the Pleistocene in different regions of the Indo-Pacific realm.