Dating an impressive Neotropical radiation: Molecular time estimates for the Sigmodontinae (Rodentia) provide insights into its historical biogeography

Nematodes Associated With Mammals in the Great American Biotic Interchange (Gabi)

“…These include nematodes of the Helligmonellidae, Spiruridae and Syphaciinae (Quentin 1969, Quentin 1971, DuretteDesset 1985, Hugot 1988. Species of these taxa are associated with cricetid rodents, which are an important faunal element of GABI, in that they apparently invaded South America from North America once, and their diversification into approximately 400 species accelerated since the Miocene (Parada et al 2013). The taxonomic decisions and interpretation of the evolutionary relationships of Heligmonellidae, Spiruridae and pinworms of the subfamily Syphaciinae (Quentin 1969, Quentin 1971, Durette-Desset 1985, Hugot 1988, was influenced by their putative specificity to their hosts, most of which were known only from their original description.…”

“…The study of extant mammal diversity and distribution, in combination with the study of the rich fossil record throughout North and South America, has enabled biologists to document the net effects of GABI on mammalian dispersion, diversification and extinction (Webb 1978, Simpson 1980, Borrero 2008. In particular, scientists have estimated dates of the impressive adaptive diversification of South American Cricetidae (Parada et al 2013, Leite et al 2014; identified signals of mass extinction in Didelphiomorpha in the Miocene (Jansa et al 2014); studied the Holocene expansion of South American species into North America (Arteaga et al 2012, Feng et al 2016…”

A new species of fish-eating rat, genus Neusticomys (Sigmodontinae), from Ecuador

“…Several morphological features differentiate them from other sigmodontines and as such have been interpreted as supporting the monophyly of the tribe (Voss 1988). Recent phylogenetic analyses, based on nuclear DNA sequences which include representatives of only two ichthyomyine genera (Rheomys and Neusticomys), have questioned the monophyly of the tribe (Martínez et al 2012;Parada et al 2013;Salazar-Bravo et al 2013). However, a recent inspection of the sequence of Neusticomys (EU649036) indicates that it may be a chimeric sequence that includes a fragment retrieved from an oryzomyine.…”

A study in contrasts: two extensive Neotropical radiations

“…At least for the Octodontoidea, the most speciose superfamily of caviomorph, this radiation was rooted in the Southern Andes and Patagonia and unfolded south-to-north (Upham and Patterson, 2012). On the other hand, the sigmodontines are sister to the Central American tylomyinestheir divergence began in the mid-to-late Miocene (9-12 Mya), and they colonized South American landscapes northto-south, as a leading element of the Great American Biotic Interchange that also brought squirrels, pocket gophers and pocket mice, deer, and peccaries (Parada et al, 2013;Leite et al, 2014). These differences in historical, geographic, and ecological context pose numerous interesting questions for transcriptomic analysis.…”