On the phylogeny of Mustelidae subfamilies: analysis of seventeen nuclear non-coding loci and mitochondrial complete genomes

<p>Abstract</p> <p>Background</p> <p>Mustelidae, as the largest and most-diverse family of order Carnivora, comprises eight subfamilies. Phylogenetic relationships among these Mustelidae subfamilies remain argumentative subjects in recent years. One of the main reasons is that the mustelids represent a typical example of rapid evolutionary radiation and recent speciation event. Prior investigation has been concentrated on the application of different mitochondrial (mt) sequence and nuclear protein-coding data, herein we employ 17 nuclear non-coding loci (>15 kb), in conjunction with mt complete genome data (>16 kb), to clarify these enigmatic problems.</p> <p>Results</p> <p>The combined nuclear intron and mt genome analyses both robustly support that Taxidiinae diverged first, followed by Melinae. Lutrinae and Mustelinae are grouped together in all analyses with strong supports. The position of Helictidinae, however, is enigmatic because the mt genome analysis places it to the clade uniting Lutrinae and Mustelinae, whereas the nuclear intron analysis favores a novel view supporting a closer relationship of Helictidinae to Martinae. This finding emphasizes a need to add more data and include more taxa to resolve this problem. In addition, the molecular dating provides insights into the time scale of the origin and diversification of the Mustelidae subfamilies. Finally, the phylogenetic performances and limits of nuclear introns and mt genes are discussed in the context of Mustelidae phylogeny.</p> <p>Conclusion</p> <p>Our study not only brings new perspectives on the previously obscured phylogenetic relationships among Mustelidae subfamilies, but also provides another example demonstrating the effectiveness of nuclear non-coding loci for reconstructing evolutionary histories in a group that has undergone rapid bursts of speciation.</p

A review of the fossil record of turtles of the clade Pan-Carettochelys

Turtles of the total clade Pan-Carettochelys have a relatively poor fossil record that extends from the Early Cretaceous. The clade is only found in Asia during the Cretaceous, but spreads to Europe and North America during the Eocene. Neogene finds are restricted to Europe, Africa and Australia, whereas the only surviving species, Carettochelys insculpta, lives in New Guinea and the Northern Territories of Australia. The ecology of fossil pan-carettochelyids appears similar to that of the extant C. insculpta, although more primitive representatives were likely less adapted to brackish water. Current phylogenies only recognize three internested clades: Pan- Carettochelys, Carettochelyidae and Carettochelyinae. A taxonomic review of the group concludes that of 25 named taxa, 13 are nomina valida, 7 are nomina invalida, 3 are nomina dubia, and 2 are nomina nuda

Skeleton of an unusual cat-sized marsupial relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian: 44-43 million years ago) of Turkey

We describe a near-complete, three-dimensionally preserved skeleton of a metatherian (relative of modern marsupials) from the middle Eocene (Lutetian: 44–43 million years ago) Lülük member of the Uzunçarşıdere Formation, central Turkey. With an estimated body mass of 3–4 kg, about the size of a domestic cat (Felis catus) or spotted quoll (Dasyurus maculatus), it is an order of magnitude larger than the largest fossil metatherians previously known from the Cenozoic of the northern hemisphere. This new taxon is characterised by large, broad third premolars that probably represent adaptations for hard object feeding (durophagy), and its craniodental morphology suggests the capacity to generate high bite forces. Qualitative and quantitative functional analyses of its postcranial skeleton indicate that it was probably scansorial and relatively agile, perhaps broadly similar in locomotor mode to the spotted quoll, but with a greater capacity for climbing and grasping. Bayesian phylogenetic analysis of a total evidence dataset comprising 259 morphological characters and 9kb of DNA sequence data from five nuclear protein-coding genes, using both undated and “tip-and-node dating” approaches, place the new taxon outside the marsupial crown-clade, but within the clade Marsupialiformes. It demonstrates that at least one metatherian lineage evolved to occupy the small-medium, meso- or hypo-carnivore niche in the northern hemisphere during the early Cenozoic, at a time when there were numerous eutherians (placentals and their fossil relatives) filling similar niches. However, the known mammal fauna from Uzunçarşıdere Formation appears highly endemic, and geological evidence suggests that this region of Turkey was an island for at least part of the early Cenozoic, and so the new taxon may have evolved in isolation from potential eutherian competitors. Nevertheless, the new taxon reveals previously unsuspected ecomorphological disparity among northern hemisphere metatherians during the first half of the Cenozoic

CarniFOSS: A database of the body mass of fossil carnivores

Motivation Body mass is one of the most important determinants of animal ecology. Unlike other important traits it is also readily inferable from fossils and it is therefore one of the only traits that can be directly analysed and compared between fossil and contemporary communities. Despite this, no comprehensive database of the body mass of larger clades of extinct species exists. Analysis of fossils has therefore been restricted to small clades or to smaller, potentially biased, subsets of species. We here describe CarniFoss, an open-access database of body masses of all 1,322 extinct species of non-pinniped Carnivoramorpha and two related extinct groups of carnivorous mammals, Hyaenodonta and Oxyaenidae. Main types of variables contained We gathered lengths of teeth of fossil and extant species and body mass for extant species and a few of the best-known fossil species. Following this we estimated body mass for all species through phylogenetic imputation. Spatial location and grain Global, terrestrial. Time period and grain We collected data on all known species within the focal groups. The known species all lived in the Palaeogene, Neogene or Quaternary (i.e., the last 66 Myr). Major taxa and level of measurement We searched for data on reported tooth size of all described species of Carnivoramorpha (excluding pinnipeds) and selected extinct related groups (Hyaenodonta and Oxyaenidae). We combined this with measured body mass for all extant species and inferred body mass based on long-bones for selected extinct species, as well as a species-level phylogeny including all extant and extinct species in the group, and inferred the body mass for all species using phylogenetic imputation. Software format Data are provided as a series of .csv files, with all metadata in a separate PDF file

Systematics and paleobiology of Carnivora and Hyaenodonta from the lower Miocene of Buluk, Kenya

Early Miocene carnivorous mammals from Buluk, Kenya, are described and discussed. Four taxa belonging to Hyaenodonta and four belonging to Carnivora are identified. Members of Hyaenodonta include Hyainailouros sulzeri, Hyainailouros cf. napakensis, a third taxon about the size of Leakitherium, represented only by postcranial material, and a fourth taxon represented by an edentulous jaw, in the size range of Sectisodon. Members of Carnivora include a new species of Cynelos jitu, which represents the largest species of Cynelos known. The first m2 of Cynelos macrodon is described, and the differentiation of this species from Cynelos ginsburgi and Cynelos peignei is confirmed. A third carnivoran species is represented by a mandibular fragment attributed to a viverrid similar to Mioprionodon, and a fourth taxon is represented by a feliform distal humerus, the size of that of a small cat. An ecomorphological guild structure analysis reveals that the Buluk carnivore have estimated body sizes spanning from 100 kg. Three very large species (>100 kg), and another two in the 30–100 kg range are present, while only two taxa are present in the 3–10 kg category. Carnivores in the 1–3 kg and the 10–30 kg categories are absent. Locomotor pattern could be obtained for only four taxa, and all are characterized by terrestrial locomotion. A minimum of three dietary classes (insectivorous, carnivorous, scavenging) are represented. The co-occurrence of multiple very large carnivores is not uncommon in early Miocene faunas, but the taphonomy of Buluk may also contribute to the favored preservation of larger and terrestrially adapted animals

An aberrant amphicyonid mammal from the latest Eocene of the Bose Basin, Guangxi, China

A new genus and species of an amphicyonid from the Bose Basin of Guangxi, south China, is short-jawed with relatively bunodont cheek teeth that are characterized by reduction in cusp number. This taxon is the oldest record of an amphicyonid from south Asia and possibly for all of Asia. Despite its antiquity, it is derived in the development of brachygnathy and differs from other early amphicyonids that have shortened faces. Evidently brachygnathy was established in this species without loss of p1-2 or m2-3, which became single-rooted from a primitive double-rooted condition

An aberrant amphicyonid mammal from the latest Eocene of the Bose Basin, Guangxi, China

A new genus and species of an amphicyonid from the Bose Basin of Guangxi, south China, is short−jawed with relatively bunodont cheek teeth that are characterized by reduction in cusp number. This taxon is the oldest record of an amphicyonid from south Asia and possibly for all of Asia. Despite its antiquity, it is derived in the development of brachygnathy and differs from other early amphicyonids that have shortened faces. Evidently brachygnathy was established in this species without loss of p1–2 or m2–3, which became single−rooted from a primitive double−rooted condition