Talk:Placentation

Table
please create a table for placentations of common fruit types like tomato, peach, pawpaw — Preceding unsigned comment added by 62.24.111.243 (talk) 03:36, 21 July 2011 (UTC)

Evolution of placentation
The evolution of placentae is an important and interesting topic that could be included in this article. I believe there is a decent amount of research, enough at least for a small section (for squamata in particular). One example: Hill.1770 (talk) 22:22, 1 October 2014 (UTC)

Placentation not essential for live birth, and please take fishes and insects (and other taxa) into account
The article says, "As placentation is essential for live birth ..."

No, it is not. For instance, some shark offspring are fed unfertilized eggs while still unborn, and all ovoviparous organisms just develop using yolk and are released from the mother live and free-living, without the need for a placenta.

Speaking of sharks, how about placenta formation in live-bearing fishes such as the guppy family and marine half-beaks? How about the well-known placentation in male seahorses and pipefishes?

For that matter, how about insects such as aphids that are born live? (Aphids have a complex life cycle with alternation of generations. The majority of them are produced by cloning and born live. Sexual individuals are produced and the sexual females lay eggs which hatch externally.) I only have a few minutes this morning and can't locate a source on whether aphids have a placenta-equivalent structure, but this paper indicates that they do supply nutrition to the developing cloned organisms in parthenogenetic development.

In any case, my point is that this is a big topic and only a very short and unrepresentative, mammal-heavy sampling is present in the article. IAmNitpicking (talk) 14:00, 5 April 2016 (UTC)
 * @ you make a number of good points. The best person to rectify this is you. Please feel free to edit the article to make sure that it includes this information. If there's anything I can do to help this happen, please let me know. --Tom (LT) (talk) 23:06, 5 April 2016 (UTC)