Originally Posted by Kess73
It also possibly begs another question about some of the larger extinct marine reptiles if they were viviparous. Were all of them air breathers?
I'm pretty sure they were all air breathers XD Although, who knows? Some sea snakes can obtain much of their oxygen from water... so maybe mosasaurs, relatives to sea snakes, could do the same? It would be helpful if they were say, waiting in ambush underwater for some unsuspecting prey to swim about... I think there's one kind of mosasaur, the Goronyosaurus, that shows some adaptations hinting at a sit and wait predatory lifestyle...
But I would expect even these mosasaurs to need surfacing on a regular basis, like the sea snakes themselves.
I insist, the question here is, why did prehistoric sea reptiles become viviparous, but sea turtles and sea iguanas did not? I can imagine sea iguanas are not as ancient, so maybe that's the reason, but, sea turtles have been around since the Jurassic... why didn´t they become viviparous or ovoviviparous during all that time?