I went back to the computer and found this:
The evolution of mammals within the synapsid lineage (mammal-like-reptiles) was a gradual process that took approximately 70 million years, beginning in the mid-Permian. By the mid-Triassic, there were many species that looked like mammals, and the first true mammals appeared in the early Jurassic. The earliest known marsupial, Sinodelphys, appeared 125 million years ago in the early Cretaceous, around the same time as Eomaia, the first known eutherian (member of placentals' "parent" group); and the earliest known monotreme, Teinolophos, appeared two million years later. After the Cretaceous-Tertiary extinction wiped out the non-avian dinosaurs (birds are generally regarded as the surviving dinosaurs) and several other mammalian groups, placental and marsupial mammals diversified into many new forms and ecological niches throughout the Tertiary, by the end of which all modern orders had appeared.
And... as i suspected, we have a common ancestor...(i've got a dinosaur vertebra of a thescelosaurus that looks almost exactly like a human vertebra; i'm going to show it to my orthopedic doctor the next time i go in)....
The first fully terrestrial vertebrates were amniotes â€” their eggs had internal membranes that allowed the developing embryo to breathe but kept water in. This allowed amniotes to lay eggs on dry land, while amphibians generally need to lay their eggs in water (a few amphibians, such as the Surinam toad, have evolved other ways of getting round this limitation). The first amniotes apparently arose in the late Carboniferous from the ancestral reptiliomorphs.
Within a few million years two important amniote lineages became distinct: mammals' synapsid ancestors and the sauropsids, from which lizards, snakes, crocodilians, dinosaurs and birds are descended.
Last edited by Knoted4ever
on Thu, Mar 24 2011, 01:48 AM, edited 1 time in total.
Illinois_______ (excerpt from E. E. Cummings: "How many winds make wonderful... and is luck The skeleton of life")