New early late Miocene species of Vishnuonyx (Carnivora, Lutrinae) from the hominid locality of Hammerschmiede, Bavaria, Germany

Background Adaptive radiation, the evolution of ecological and phenotypic diversity from a common ancestor, is a central concept in evolutionary biology and characterizes the evolutionary histories of many groups of organisms. One such group is the Mustelidae, the most species-rich family within the mammalian order Carnivora, encompassing 59 species classified into 22 genera. Extant mustelids display extensive ecomorphological diversity, with different lineages having evolved into an array of adaptive zones, from fossorial badgers to semi-aquatic otters. Mustelids are also widely distributed, with multiple genera found on different continents. As with other groups that have undergone adaptive radiation, resolving the phylogenetic history of mustelids presents a number of challenges because ecomorphological convergence may potentially confound morphologically based phylogenetic inferences, and because adaptive radiations often include one or more periods of rapid cladogenesis that require a large amount of data to resolve. Results We constructed a nearly complete generic-level phylogeny of the Mustelidae using a data matrix comprising 22 gene segments (~12,000 base pairs) analyzed with maximum parsimony, maximum likelihood and Bayesian inference methods. We show that mustelids are consistently resolved with high nodal support into four major clades and three monotypic lineages. Using Bayesian dating techniques, we provide evidence that mustelids underwent two bursts of diversification that coincide with major paleoenvironmental and biotic changes that occurred during the Neogene and correspond with similar bursts of cladogenesis in other vertebrate groups. Biogeographical analyses indicate that most of the extant diversity of mustelids originated in Eurasia and mustelids have colonized Africa, North America and South America on multiple occasions. Conclusion Combined with information from the fossil record, our phylogenetic and dating analyses suggest that mustelid diversification may have been spurred by a combination of faunal turnover events and diversification at lower trophic levels, ultimately caused by climatically driven environmental changes. Our biogeographic analyses show Eurasia as the center of origin of mustelid diversity and that mustelids in Africa, North America and South America have been assembled over time largely via dispersal, which has important implications for understanding the ecology of mustelid communities.

Phylogenies underpin comparative biology as high-utility tools to test evolutionary and biogeographic hypotheses, inform on conservation strategies, and reveal the age and evolutionary histories of traits and lineages. As tools, most powerful are those phylogenies that contain all, or nearly all, of the taxa of a given group. Despite their obvious utility, such phylogenies, other than summary 'supertrees', are currently lacking for most mammalian orders, including the order Carnivora. Carnivora consists of about 270 extant species including most of the world's large terrestrial predators (e.g., the big cats, wolves, bears), as well as many of man's favorite wild (panda, cheetah, tiger) and domesticated animals (dog, cat). Distributed globally, carnivores are highly diverse ecologically, having occupied all major habitat types on the planet and being diverse in traits such as sociality, communication, body/brain size, and foraging ecology. Thus, numerous studies continue to address comparative questions within the order, highlighting the need for a detailed species-level phylogeny. Here we present a phylogeny of Carnivora that increases taxon sampling density from 28% in the most detailed primary-data study to date, to 82% containing 243 taxa (222 extant species, 17 subspecies). In addition to extant species, we sampled four extinct species: American cheetah, saber-toothed cat, cave bear and the giant short-faced bear. Bayesian analysis of cytochrome b sequences data-mined from GenBank results in a phylogenetic hypothesis that is largely congruent with prior studies based on fewer taxa but more characters. We find support for the monophyly of Carnivora, its major division into Caniformia and Feliformia, and for all but one family within the order. The only exception is the placement of the kinkajou outside Procyonidae, however, prior studies have already cast doubt on its family placement. In contrast, at the subfamily and genus level, our results indicate numerous problems with current classification. Our results also propose new, controversial hypotheses, such as the possible placement of the red panda (Ailuridae) sister to canids (Canidae). Our results confirm previous findings suggesting that the dog was domesticated from the Eurasian wolf (Canis lupus lupus) and are congruent with the Near East domestication of the cat. In sum, this study presents the most detailed species-level phylogeny of Carnivora to date and a much needed tool for comparative studies of carnivoran species. To demonstrate one such use, we perform a phylogenetic analysis of evolutionary distinctiveness (EDGE), which can be used to help establish conservation priorities. According with those criteria, and under one of the many possible sets of parameters, the highest priority Carnivora species for conservation of evolutionary diversity include: monk seals, giant and red panda, giant otter, otter civet, Owston's palm civet, sea otter, Liberian mongoose, spectacled bear, walrus, binturong, and the fossa. Published by Elsevier Inc.