Solenodons–the Last Poison Fanged Mammals

The Cuban Solenodon, Solenodon cubanus (photo by Dr. Jorge Brocca)

Ferrebeekeeper has written about the ancient and eccentric platypus, the most poisonous mammal left on the planet.  In that article we alluded to the other poisonous genus of mammals, the solenodons.  Although they are not quite as ancient and strange as the monotremes (the platypus and the echidna), solenodons are still extremely old and weird.  The genus consists of only two species, the Hispaniolan Solenodon (Solenodon paradoxus) and the Cuban Solenodon (Solenodon cubanus), both of which weigh about 1 kg (2.2 lb). Resembling large shrews, the creatures belong to the order Soricomorpha along with other small insectivorous creatures like shrews and true moles–however the solenodons are quite distinct from these familiar creatures and future taxonomy may break the order apart.  Paleozoologists believe that Solenodons evolved in the late Cretaceous (about 70 to 80 million years ago), when the dinosaurs still ruled the planet. A population of the creatures split off from the ancestors of moles, and shrews (perhaps when the Caribbean islands rafted away from Central America due to tectonic movement).

Solenodons excavate burrows where they live together in family units containing up to eight members.  They use their elongated cartilaginous snouts for hunting arthropods and small lizards.  In addition to long proboscis-like snouts, solenodons have naked scaly tails, beady eyes, and coarse dark fur (so they are probably not dethroning red pandas and kittens in terms of glossy calendar sales anytime soon).  The mammary glands of Solenodons are not located in the same location as those of other mammals but are found near the tail–almost on the creatures’ buttocks. This is not even the most unusual feature of the strange animals. The zoology website, thelastsurviors.org, describes the unique features of solenodon saliva and teeth

…most notably the deep grooves in their lower incisors, which act as channels to inject venomous saliva into their prey. The name ‘solenodon’ means ‘grooved tooth’. Solenodons are the only living mammals with a dental venom delivery system, which is more typical of snakes. However, several ancient fossil mammals also show similar dental characteristics, suggesting that this kind of venom delivery was once much more common but has been lost in all other living mammals.

Unique toxic saliva and grooved injector teeth do not seem to have helped the poor solenodons.  Invasive mongooses and feral cats swept through the populations of Hispaniolan and Cuban solenodons and both species were reported extinct in the twentieth century. Happily, in both instances, the reports were wrong. The Hispaniolan solenodon was believed to be functionally extinct until 1907, when it was found living in the interior jungles and mountains of Hispaniola (although it may be extinct in deforested Haiti). Cuban solenodons were declared extinct in 1970 but then found in the dense eastern jungles  Although both species are now protected, it is unclear whether the last poison fanged mammal can compete against vigorous invaders.

The Hispaniolan Solenodon (Solenodon paradoxus)

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