The poisons are variations on digestive enzymes, only turned up to 11 potency-wise. Lots of enzyme producing organs have bladders to store their output until needed, so that likely would have copy-pasted in at the same time, and there are several species of reptiles which are venomous, but don’t have fangs. There seems to be a progression of teeth near the venom entry point becoming longer and grooved, eventually culminating in fangs.
Digestion first, then pre-digestive saliva (your saliva has digestive enzymes too for that matter) then more potent saliva, then teeth to stuff it into the prey more effectively once it was strong enough to help with incapacitation and not just chewing, then more specialized saliva, then more specialized teeth. Pretty easy to see how it would have developed a piece at a time.
The poisons are variations on digestive enzymes, only turned up to 11 potency-wise. Lots of enzyme producing organs have bladders to store their output until needed, so that likely would have copy-pasted in at the same time, and there are several species of reptiles which are venomous, but don’t have fangs. There seems to be a progression of teeth near the venom entry point becoming longer and grooved, eventually culminating in fangs.
Digestion first, then pre-digestive saliva (your saliva has digestive enzymes too for that matter) then more potent saliva, then teeth to stuff it into the prey more effectively once it was strong enough to help with incapacitation and not just chewing, then more specialized saliva, then more specialized teeth. Pretty easy to see how it would have developed a piece at a time.