H. et al 2012. The oldest-known amniotic embryos suggest vivparity in mesosaurs. Historical Biology 24 620–630. Modesto, S.P. (2006). "The cranial skeleton...

including turtles (Chelonia). Some other groups were anapsids, such as the mesosaurs. Pough F.H. et al. 2002. Vertebrate life, 6th ed. Prentice Hall, NJ. ISBN 0130412481...