X is for Xenosaurus newmanorum, Newman's knob scaled lizard
This prehistoric-looking lizard is part of an ancient family, Xenosauridae, which diverged from all other living reptiles more than 85 million years ago. To put this in perspective, our family, Hominidae, split from all other primates less than 20 million years ago!
Xenosaurids are unusual amongst lizards as they are viviparous, giving birth to live young, whereas most lizards lay eggs. Females are ‘pregnant’ for up to 12 months and there is evidence they provide maternal care for their offspring!
It is found in the Neotropics and the Nearctic and is an ambush predator. A major threat is forest conversion for coffee plantations, which is destroying their natural habitat. This species is also mistaken for the venomous Heloderma lizards, with which it is sympatric, and persecuted by local people.