Discussion from the WSED Facebook group (you have to be a member to read posts):
Do venomous snakes have salivary glands other than the obvious ones attached to the fangs? If so, does the saliva contain the same structures as their venom?
Snakes have many different salivary glands. The venom glands evolved from a salivary gland. Some snakes had a fusion of salivary and venom and a separation, but that is a bit messy evolution work currently. In short though, venomous snakes have both. Which is why it is silly when people say something is not venomous, but it has “modified toxic saliva”. Venom is “modified toxic saliva”. So if you say rear-fanged snakes have “toxic saliva”…you should be saying front-fanged do as well.
~ Mace Montana
“They have normal mucosal salivary glands in the soft tissues of their mouths to aid in swallowing.”
We know that the venom glands are subset of modified glands – but the typical glands haven’t changed. The evolutionary selection pressure that guided the adaption of the venom glands didn’t really change the pressures to need to lubricate the esophagus and upper airways.
~ Griffin McDaniels