Researchers at Louisiana State University have discovered a new genus and species on a remote, mountainous island in Indonesia. This new discovery is the third new genus described by this group of scientists since 2012, and identifies a rodent with features never seen by the scientific community before.
The animal is a shrew rat with a large, flat, pink nose and forward-facing nostrils for which they named the Hog-nosed rat, or Hyorhinomys stuempkei.
With extremely large ears, long hind legs that may be used for hopping, long white incisors and very long urogenital hairs, the Hog-nosed rat is so genetically different from any other species that the scientists described it as a new genus.
Long incisors are a trait of shrew rats. But the Hog-nosed rat has especially long incisors. Another distinct characteristic of the Hog-nosed rat is that it lacks a jaw muscle attachment point found in most mammals called the coronoid process on the dentary bone.
The loss of the coronoid process indicates a weak jaw musculature and a diet that does not require vigorous chewing. The scientists found that the new species eats earthworms and beetle larvae.
The island of Sulawesi in Indonesia is geographically complex, mountainous and challenging to scientifically sample. Little research has been conducted on the island since the early 20th century.
The study site for this discovery was a moss-covered habitat on Mt. Dako at about 1,600 meters elevation and a two-day trek from the nearest village.
The scientists described the Few-toothed shrew rat, or Paucidentomys vermidax, in 2012. One of the reasons why scientists have thought that rodents have been evolutionarily successful is they have incisors for gnawing and molars for grinding.
In 2014, the scientists described the Sulawesi water rat, Waiomys mamasae, which was known to villagers and their guides but not to the scientific community. Villagers use this animal as a talisman to protect their homes against fire.
These animals are new species within new genera, because the animals could not be placed within any existing group. After sequencing the DNA from the specimens, the scientists had the molecular evidence to confirm the species’ unique distinctions.