Amniotic egg appears very early in reptilian evolution. Egg has several special extra-embryonic membranes, which allow it to develop on land independent of water. Just as significant as evolution of ...

Mr. Howard recounts the diversity of ways fertilization is achieved in different species, an evolved array of techniques and structures ... the crucial egg membranes, notably the amniotic sac ...

Eggs, in their simplest form as female reproductive cells, existed long before chickens. The breakthrough came with the evolution of hard-shelled amniotic eggs, which appeared around 325 million ...

Amniotic egg appears very early in reptilian evolution. Egg has several special extra-embryonic membranes, which allow it to develop on land independent of water. Just as significant as evolution of ...