2006-09-04 20:35:25 · 7 answers · asked by pony 1 in Environment
Nobody knows. And that is the only real answer you wil get.
The first problemi s defining what a "land animal" is. Is a limpet a land animal? It an survive out of water for days at a time, but it has to return to the sea eventually.
How about an earthworm? Is that a land animal? And if they are then is an earthworm that lives in the mud on the bottom of a pond a land animal?
Probably the first land animals were flatworms. The difference between terrestrial and aquatic planarians is almost non-existent, and numerous species move between aquatic and terrestrial existence at will.
So it seems likely that planarians crawled out of the streams almost as soon as they evolved.
2006-09-04 21:11:00 · answer #1 · answered by Anonymous · 0⤊ 0⤋
First came insects, then walking fish, and amphibians.
Everything moved upwards in complexity then as a split occurred between cold blooded and warm blooded creatures. Swim fins developed into flying wings and tails.
Other swim fins developed into legs, then jointed legs, even with feet.
2006-09-06 04:42:44 · answer #2 · answered by zahbudar 6 · 0⤊ 1⤋
Molluscs.
2006-09-04 20:45:49 · answer #3 · answered by Keyring 7 · 0⤊ 0⤋
Snake?
2006-09-04 20:37:00 · answer #4 · answered by iLL_TeK_NeekZ 4 · 0⤊ 0⤋
Dinosaurs...
2006-09-04 20:36:48 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Reptiles. probably lizards of some sort.
2006-09-04 21:38:59 · answer #6 · answered by findingmyplace 1 · 0⤊ 0⤋
lung fish
2006-09-04 21:30:34 · answer #7 · answered by CARLOS_TINCO 2 · 0⤊ 0⤋