seeds and placentas won’t exist for a long age yet, and there’s no other way to reproduce outside of standing water bodies.
Did you mean to write ‘eggs’ rather than placentas? Land-dwelling animals evolved long before placentas did. And long before tetrapods did—arthropodes came on land first, as well as many other (“worm”) phyla such as nematodes and annelids—land ecology wouldn’t be the same without insects and earthworms!
Plants, too, can reproduce on land without seeds, and for a long time they did: witness the bryophytes (liverworts, mosses) and seed-less vascular plants such as the horsetail.
In any case, needing water temporarily for reproduction does not prevent adults from living on land. All life needs water in the end.
Yeah, my language is *at best* imprecise here, mostly in the interests of legibility and not dumping too much information in a sentence that was meant to direct your attention elsewhere. The technical term I was dancing around was “amniotes”, animals that develop an amniotic sac. Even that would have been wrong because it’s only concerned with vertebrate clades, which I wasn’t even thinking of at the time, so I appreciate you pointing that out and I’ve tweaked it slightly
(One brief correction, mosses and vascular ferns do indeed require standing water for reproduction- although they can take advantage of transient puddles and such when they have to. This limits them to low-lying areas, and it’s a primary reason that you don’t see fern forests around today the way you did back in the Carboniferous.)
Did you mean to write ‘eggs’ rather than placentas? Land-dwelling animals evolved long before placentas did. And long before tetrapods did—arthropodes came on land first, as well as many other (“worm”) phyla such as nematodes and annelids—land ecology wouldn’t be the same without insects and earthworms!
Plants, too, can reproduce on land without seeds, and for a long time they did: witness the bryophytes (liverworts, mosses) and seed-less vascular plants such as the horsetail.
In any case, needing water temporarily for reproduction does not prevent adults from living on land. All life needs water in the end.
Yeah, my language is *at best* imprecise here, mostly in the interests of legibility and not dumping too much information in a sentence that was meant to direct your attention elsewhere. The technical term I was dancing around was “amniotes”, animals that develop an amniotic sac. Even that would have been wrong because it’s only concerned with vertebrate clades, which I wasn’t even thinking of at the time, so I appreciate you pointing that out and I’ve tweaked it slightly
(One brief correction, mosses and vascular ferns do indeed require standing water for reproduction- although they can take advantage of transient puddles and such when they have to. This limits them to low-lying areas, and it’s a primary reason that you don’t see fern forests around today the way you did back in the Carboniferous.)