Shrew Shot Venom Through Blood-Red Teeth

One of the mandibles (part of the jaw) of the extinct shrew, Dolinasorex glyphodon, found in Spain. Foto: J. Trueba CREDIT:

Scientists have found the fossil remains in Spain of a new species of mega-shrew that was capable of shooting venom out of blood-colored teeth.

The researchers describe the extinct shrew, Dolinasorex glyphodon, as "giant." Its body mass reached only 2.1 ounces (60 grams), but that is about four times heavier than a modern, large-sized member of the same family of insect-eating shrews (the Soricidae), such as the water shrew (Neomys fodiens) which weighs in at around half an ounce (14 grams).

The remains also reveal that the red-toothed shrew was capable of "injecting toxic saliva" like snakes do, via a "narrow and conspicuous channel" located on the inside surface of its lower incisors, said Juan Rofes, lead author of a new study of the shrew and a researcher in the Paleontology Department at the University of Zaragoza (UNIZAR).

"This was a mechanism very similar to that of the modern solenodons and almiquis, which are close relatives of the shrews and live on the islands of Cuba and Haiti," Rofes told SINC, a Spanish science news and information service. The results of his study are in the April issue of the Zoological Journal of the Linnean Society.

The remains of the strange mammal were found in a deposit in Gran Dolina de Atapuerca, in Burgos, Spain, in layers that date to between 780,000 and 900,000 years ago. The site also is rich in fossils of early humans. The animal was more closely related to eastern Asian than European shrews, Rofes said. It could have arisen and evolved in eastern Asia and then migrated to the Iberian Peninsula, he said.

"To date, all the medium to large-sized Soricidae fossils discovered in the deposits of the Sierra de Atapuerca belonged to Beremendia fissidens, a species of … shrew that was distributed throughout Europe," Rofes said.

{{ video="LS_090519_shrew" title="" caption="" }}

• Video - Venomous Mega-Shrew Fossil in Spain
• Evolution's Most Extreme Mammals
• Top 10 Deadliest Animals