Toothed earthworm rat
| Toothed earthworm rat | ||||||||||||
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Indonesian postage stamp on the poorly toothed earthworm rat |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Paucidentomys | ||||||||||||
| Esselstyn , Achmadi & Rowe , 2012 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Paucidentomys vermidax | ||||||||||||
| Esselstyn, Achmadi & Rowe, 2012 | ||||||||||||
The toothed earthworm rat ( Paucidentomys vermidax ) is a rodent species from the mountain forest of the Indonesian island of Sulawesi that was first described in 2012 . The species is remarkable because it lacks the molars in the upper and lower jaw. The rodent species holotype and paratype was caught during a research excursion in the mountains of northern Sulawesi Selatan (South Sulawesi) and Sulawesi Barat (West Sulawesi). Paucidentomys vermidax is the only species of the monotypical genus Paucidentomys . The generic name means "little-toothed mouse", the epithet vermidax means "worm eater".
features
The tooth-poor earthworm-rat is a medium-sized rat-like rodent, which outwardly resembles a shrew and, compared to other Sulawesian shrew- like rodents, has a very elongated snout. The eyes are small, the ears are long. The fur is soft and thick, dark gray at the base and brown at the ends of the hair, resulting in a gray-brown fur color. The tail is about 20% longer than the length of the head and torso , thick, hairy and dark gray on the top and dirty whitish on the underside. The upper and lower jaw each have only two incisors and are otherwise completely toothless. The tooth formula of animals is:
The two upper incisors are short, with a higher point in front and a second, shorter point a little further back on the tooth. Both tips are connected by a sharp cutting edge. In the maxillary , remnants of the tooth sockets (alveoli) of the molars are visible under a thin layer of almost transparent bone tissue. One wing leg is missing. The lower jaw is long and delicate. There are no conspicuous starting points for the muscles. The incisors in the lower jaw are almost horizontal, single-pointed, sharp and thin.
Way of life
The paratype's stomach contained pieces of earthworms about 5 to 10 mm long, but no other remains of food. It is assumed that the toothless earthworm rat feeds exclusively on soft animal prey, possibly only earthworms. With its sharp incisors, Paucidentomys vermidax can cut the earthworms into pieces before they are swallowed. The tooth-poor earthworm rat is likely a terrestrial (on the ground) animal whose habitat is restricted to moist forests above an altitude of 1,500 meters.
literature
- Jacob A. Esselstyn, Anang Setiawan Achmadi, Kevin C. Rowe: Evolutionary novelty in a rat with no molars. In: Biology Letters. Vol. 8, No. 6, 2012, ISSN 0003-0090 , pp. 990-993, doi : 10.1098 / rsbl.2012.0574 .
- Jacob A. Esselstyn, Anang Setiawan Achmadi, Kevin C. Rowe: Online Supplementary Materials for: Evolutionary novelty in a rat with no molars. PDF; 3.82 MB .
Web links
- scinexx, Wednesday, August 22, 2012, Rat can neither chew nor gnaw, scientists discover rodents with unusual teeth in Indonesia