Those two evolutionary improvements needed the development that is previous of fertilization. Simply put, the deposition of semen by the male to the female’s reproductive tract additionally the sperm’s subsequent penetration for the ovum had been necessary prior to the shelled egg could occur.
The deposition of the male’s sperm ins > penis (as in turtles order Testudines and crocodiles order Crocodylia, or Crocodilia) or hemipenes (as in lizards and snakes order Squamata) in living reptiles. Your penis is a homologue of this penis that is mammalian and its own existence in reptiles suggests that this organ arose at the beginning of the development of this amniotes and ahead of the beginning of reptiles and synapsids. Continue reading “The development of amniotic development while the shelled egg enabled vertebrates to be completely terrestrial”