Palaeos:		Amniota
The Vertebrates		Amniota

Amniota

REPTILIOMORPHA
|
`--AMNIOTA
    |--Casineria
    |--Westlothiana
    `--Crown Amniota
       |--Sauropsida (= Reptilia)
       |  |--ANAPSIDA
       |  `--EUREPTILIA 
       `--SYNAPSIDA

The amniote egg was one of evolution's great success stories, because it allowed land animals to reproduce separately from water. We don't really know when the transition from amphibian (dependemnt on water) to reptile (totally terrestrial) occurred, but it was sometime during the early Carboniferous period, not long after the evolutionary radiation of the amphibians (tetrapods). Indeed, it seems like proto-reptiles were among the first of these many lineages to diverge, and a number of lineages, of various stages of advancement, co-existed with traditional amphibians for many millions of years. It was only when the climate became drier and the great swamps dissappeared that the reptiles had an advantage over their amphibious brethren. Here we continue the story of these proto-reptiles, and speculate on when they made the transition from reptile-like amphian to amphibian-like proto-reptile. MAK111108