Thursday, February 20, 2020

[Mammalogy • 2020] Ichthyomys pinei • A New Species of Crab-eating Rat of the Genus Ichthyomys (Rodentia, Cricetidae, Sigmodontinae) from Ecuador

Ichthyomys pinei
 de Córdova, Nivelo-Villavicencio, Reyes-Puig, Pardiñas & Brito, 2020

Pine’s Crab-eating Rat | Rata Cangrejera de Pine  || DOI: 10.1515/mammalia-2019-0022
Illustration: Glenda Pozo-Zamora 

Based on two adult specimens collected in the Río León (Azuay, Ecuador), we describe a new highland species of a small crab-eating rat of the genus Ichthyomys Thomas (Rodentia, Cricetidae, Ichthyomyini). It is distinguishable from Ichthyomys hydrobates (Winge, 1891), the species phenetically closest to it, by its smaller size, bicolored tail (unicolored in I. hydrobates), broad and heavily fringed hindfoot (narrower and moderately fringed in I. hydrobates), and several craniodental traits (e.g. rostrum short broad; nasals anteriorly truncated; interorbital region narrow; supraorbital margins smoothly rounded; supraorbital foramina small, zygomatic plate very narrow; incisors opisthodont; length of M3 half that of M2). The new species occurs in the western Andes in southern Ecuador and is allopatric with Ichthyomys stolzmanni Thomas, 1893, which also has a bicolored tail but is larger. The new species brings the number of Ecuadorean Ichthyomys to four, Ecuador thus becoming the country with the greatest diversity of Ichthyomyini (four genera and eight species).

Keywords: Andes; biodiversity; Ichthyomyini; morphology; Neotropics; new species; taxonomy

Figure 2: Dorsal and ventral views of stuffed study skins of Ecuadorean species of Ichthyomys, including
(A, B) adult female Ichthyomys pinei, sp. nov. (MZUA 234, holotype); (C, D) adult male I. stolzmanni (MECN 4914); (E, F) adult male I. tweedii (MECN 12229); (G, H) adult male I. hydrobates (MEPN 5834). Scale=10 mm.

Illustration: Glenda Pozo-Zamora 

Family Cricetidae Fischer, 1817
Subfamily Sigmodontinae Wagner, 1843
Tribe Ichthyomyini Vorontsov, 1959

Genus Ichthyomys Thomas, 1893

Ichthyomys pinei sp. n.  
Pine’s Crab-eating Rat or Rata Cangrejera de Pine

Etymology: This species is named in honor of Ronald H. Pine (Lawrence, KS, USA). Dr. Pine has engaged in vertebrate surveys in various countries in five continents, and has published numerous scholarly articles, mostly focused on Latin American bats, rodents and marsupials. The species epithet is formed from the surname “Pine”, taken as a noun in the genitive case, with the Latin suffix “i” (ICZN 31.1.2).

Javier Fernández de Córdova, Carlos Nivelo-Villavicencio, Carolina Reyes-Puig, Ulyses F.J. Pardiñas and Jorge Brito. 2020. A New Species of Crab-eating Rat of the Genus Ichthyomys, from Ecuador (Rodentia, Cricetidae, Sigmodontinae). Mammalia.  DOI: 10.1515/mammalia-2019-0022

Scientists discover a new crab-eating rat species in Ecuador via @DG_Discoveries