The truly highlight of our research into viper venom has got to be the pair of Fea's vipers (Azemiops feae) we had living in our bedroom. The reason for their residing there was that they are very sensitive to heat and do best with an ambient temperature of about 22 degrees C. Good enough excuse for us to pop them into the bedroom and crank the air-conditioner.
Despite lacking the heat-seeking pits characteristic of the pit-vipers, the Fea's vipers actually are genetically right at the base of the pit-viper branch of the viper evolutionary tree. In fact, they may be able to do a bit of heat detection themselves.
An interesting titbit to emerge from our research has been that the venom profile of the Fea's viper is remarkably similar to that of the Wagler's viper (Tropidolaemus wagleri).
The vipers are the most ancient split off of the Colubroidea tree (Advanced snakes), splitting before even any of the 'colubrids'. They lack the 3FTx toxins, indictating that this toxin recruitment event came subsequently. However, present in the venoms of the vipers are a number of toxin types that are also found in the elapid and 'colubrid' venoms. We have recently worked out which toxin types are truly ancestral, predating even the vipers and consequently were present in the venom of the very first venomous snake! This work showed how the snakes assembled their chemical arsenal and provided insights into one of the most interesting adaptations in evolution.
