I saw this while out on the Coyote Highway:
Archive for the ‘Rodents’ Category
A gray squirrel drey
Posted in Rodents, wildlife, tagged Eastern gray squirrel, gray squirrel on November 25, 2012| 1 Comment »
A new species of nearly toothless, worm-eating rat discovered on Sulawesi
Posted in New species, Rodents, wildlife, tagged Paucidentomys vermidax., shrew rat on August 22, 2012| 7 Comments »
You’ll not see another rodent with a skull like this.
All other rodents known to science have chisel-shaped incisors that meet in the front. These teeth grow continuously, and their continuous grinding keeps them sharp and pointed.
All other rodents know to science have molars for grinding down food.
This rodent has neither of these features.
This all sounds bizarre, but this skull belongs to a new species of rat that was discovered on the Indonesian island of Sulawesi.
This animal was just described to science yesterday in the journal Biology Letters.
If one looks closely at the skull, one can see that it has no molars– at all.
This is very weird for a rodent.
It has incisors. The bottom incisors look very much like those of normal rodents, chisel-shaped, but the top incisors are little fangs.
This new species captured by a team of researchers who set up “pitfall traps”– buried buckets that are level with ground that allow small animals to fall in.
The researchers caught two of them, but they didn’t know until they examined the skull of a dead specimen that they had such weird dentition.
These rats live in high-elevation forests that are covered in moss.
The rats have evolved to live entirely on earthworms.
Earthworms aren’t very hard, so the rats have lost their rodent dentition.
Their teeth are now “worm grabbers.”
Their only purpose is to catch the worm, when the rat sucks it out of the ground with its long muzzle.
The species has been give the name Paucidentomys vermidax. Paucidentomys means “few-toothed mouse,” and verimdax means “worm-eater.”
This new species, which has not yet been given a common name, is closely related to the shrew rats that are found only on Sulawesi and the Philippines. Indeed, this animal is itself a new species of shrew rat. Shrew rats are largely insectivorous in their diet. They still have the typical rodent dentition. They have simply evolved into the shrew’s ecological niche.
This one, however, has become quite specialized to eating only worms.
It’s really unique among all rodents.
No other species of rodent has evolved such bizarre dentition to accommodate such a specialized diet.
Evolution produces lots of bizarre things.
But this is one of the most bizarre.
From a lineage that has produced the most diverse and successful order of mammals on the planet largely through its peculiar dentition, a species has evolved that has totally lost that defining characteristic of its order.
No longer can we say that all rodents have grinding incisors and molars.
We can only say all rodents but one.
And that’s this little shrew-like creature from Sulawesi.
The few-toothed, worm-eating mouse!




The Guinea pig is a popular first pet for many children, but the identity of its wild ancestor remains unclear.








