Hog-nosed rat discovery in Sulawesi, Indonesia

This 1 October 2015 is about a newly discovered rat species in Sulawesi, Indonesia.

A hog-nosed shrew rat (Rodentia: Muridae) from Sulawesi Island, Indonesia

Jacob A. Esselstyn, Anang S. Achmadi, Heru Handika, Kevin C. Rowe

29 September 2015

Abstract

We document a new genus and species of shrew rat from the north peninsula of Sulawesi Island, Indonesia. The new taxon is known only from the type locality at 1,600 m elevation on Mt. Dako, in the district of Tolitoli.

It is distinguished from all other Indonesian murines by its large, flat, pink nose with forward-facing nares. Relative to other Sulawesi murines, the species has extremely large ears (~ 21% of head and body length), very long urogenital hairs, prominent and medially bowing hamular processes on the pterygoid bones, extremely long and procumbent lower incisors, and unusually long articular surfaces on the mandibular condyles.

Morphologically, the new taxon is most similar to a group of endemic Sulawesi rats known commonly as “shrew rats.” These are long faced, carnivorous murines, and include the genera Echiothrix, Melasmothrix, Paucidentomys, Sommeromys, and Tateomys. Our Bayesian and likelihood analyses of DNA sequences concatenated from 5 unlinked loci infer the new shrew rat as sister to a clade consisting of Melasmothrix, Paucidentomys, and Echiothrix, suggesting that Sulawesi shrew rats represent a clade.

The Sulawesi water rat, Waiomys mamasae, was sister to the shrew rats in our analyses. Discovery of this new genus and species brings known shrew rat diversity on Sulawesi to 6 genera and 8 species. The extent of morphological diversity among these animals is remarkable considering the small number of species currently known.