Bisonalveus browni

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Bisonalveus browni

Fossil

Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Pantolesta
Family:	Pentacodontidae
Genus:	Bisonalveus
Species:	B. browni

Binomial name

Bisonalveus browni
Gazin, 1956

Bisonalveus browni is an extinct mammal, once believed to be related to the modern pangolin.

It was discovered in 1956 in Alberta, Canada. It is known primarily from fossil jaws dating back 60 million years ago, during the Palaeocene epoch. This ancient mammal was probably something like our modern shrews.

Interestingly, the canine teeth in Bisonalveus have grooves that may have been used for delivering a venomous bite. The canines that would contain venom do not correspond with the lower jaw, rendering these teeth as deadly fangs, as in many species of poisonous snakes. There are few modern mammals that are venomous. The male platypus has a hollow foot spur attached to a venom sac. The only other venomous mammals are four species of shrew and the two species of solenodon which have venomous saliva, and the slow loris which has poison glands on its arms. Possibly like the modern solenodon, Bisonalveus bit its victims to inject its toxic saliva and buried the remains in a cache for later consumption. However, because other nonvenomous mammals, such as baboons and other primates, have similar grooves some scientists have questioned whether these grooves truly indicate venom delivery.

[edit] References

Folinsbee K, Muller J, Reisz RR (2007) "Canine grooves: morphology, function, and relevance to venom" Journal of Vertebrate Paleontology 27:547-551.

Fox RC, Scott CS (2005). "First evidence of a venom delivery apparatus in extinct mammals". Nature 435 (7045): 1091–3. doi:10.1038/nature03646. PMID 15973406

Orr CM, Delezene LK, Scott JE, Tocheri MW, Schwartz GT (2007) "The comparative method and the inference of venom delivery systems in fossil mammals" Journal of Vertebrate Paleontology 27:541-546.