Almost toothless rodent survives on soft prey

[Nipuna]

CHEW over this evolutionary story. Rodents, which account for nearly 40 per cent of living mammal species, owe much of their success to their teeth - yet one rodent has got rid of most of its gnashers.

Paucidentomys vermidax was discovered in Indonesia last year by Jacob Esselstyn of McMaster University in Hamilton, Ontario, Canada, and his colleagues. It has no molars, and its incisors are shaped for gripping food rather than gnawing (Biology Letters, DOI: 10.1098/rsbl.2012.0574).

Esselstyn found that the rodent's stomach was packed with the remains of earthworms. He thinks it might live entirely on soft-bodied animals, which would explain why it would not need so many teeth.