godot - 2010-05-04
As far as I can tell, not even cynodonts, so our last shared ancestor with these fellas is at least 256 mya.
Its remarkable just how many times placental viviparity has independently evolved in worms, scorpions, some sharks, some lizards, including these skinks, and subclass theria among mammals. Like the eyeball, it seems to be such a useful innovation, reinvented so many times, that I would not at all be suprised if the first extraterrestrial technological species we meet also bears live young.
|