Talk:River dolphin

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Hope I didn't muck up Rice's classification when reformatting the list. I might have because I don't understanding the foll:

"In the most recent classification (Rice, 1998) there are four families that make up the river dolphins. The Platanistidae is listed as the only extant family of the Platanistoidea superfamily. The previously accepted classification treated all four families as belonging to this superfamily"

Does this really mean Rice has a superfamily containing only one family? Can you have such a thing? Can anyone clarify? And please fix the list if I mucked up. Nurg 08:47, 28 Nov 2004 (UTC)

Only one extant family, so presumably there are extinct families in this superfamily. In any case, if there one superfamily, containing a group of families, then any one other family must be another superfamily by definition. jimfbleak 10:25, 28 Nov 2004 (UTC)

i've read it four times now, and it still doesn't make sense. there just can't be only one existing family Platanastidae in the superfamily Platanastoidea. if each river dolphin belongs to its own monotypic family (allowing for the exception of the ganges and indus, of course) as both charts show, then we're missing at least one more superfamily. but i don't think that's right. from what i can recall, all four were of late classified in one family in one superfamily -- this is what changed with rice in 1998. this isn't shown on the charts. am i confused, or is it really confusing? - Metanoid (talk, email) 11:01, 25 March 2008 (UTC)

ok, so i haven't found anything yet in reeves about previous classifications outside this: "The river dolphins are a disparate group of four species that have been classified in a number of different ways. Scientists have sometimes assigned them to one family, but the current convention is to view them as belonging to four separate families, each containing a single genus. The river dolphins share a few primitive cranial features, and all possess long narrow jaws, but they are otherwise quite distinct from each other. Only three of the four species actually live in rivers." (reeves guide to marine mammals of the world, 2002, p.299. - Metanoid (talk, email) 11:18, 25 March 2008 (UTC)

[edit] Taxonomy

It is perhaps not the best place to ask, but can anyone clarify for me term superfamily in context of Platanistoidea and river dolphins? Is Platanistoidea a monophyletic taxon? If yes, how could it occur that related species survived in so isolated and so wide distributed river habitats? If not, why all river dolphins have some features in common, particularly elongated snout? Convergent evolution? What does modern biology say about it?

Besides, taxonomy in River dolphin article shows that family Delphinidae, or ocean dolphins, is included into superfamily Platanistoidea, while taxonomy in Cetacea article treats superfamily Platanistoidea as being isometric to any other family (including Delphinidae). Which interpretation is correct? Clarifying this will help me to understand notions of sub-, super- and infra-taxons, because when I studied in school, there were no superfamilies or infraorders, and that was my last experience of formal biological education :). Verdi1 14:35, 7 May 2006 (UTC)

MEKONG RIVER DOLPHIN

Why is it not listed in here? Is there a reason?

http://www.mekongdolphin.org/irrawaddy_dolphin.htm

The Irrawaddy Dolphin is not a River dolphin, but is classed with the oceanic dolphins. See the article for the distinction. --Dante Alighieri | Talk 10:03, 29 December 2006 (UTC)

[edit] Mississippi River dolphin?

I remember reading a few years back about there being a species of Mississippi River dolphins, hunted to extinction in the 19th Century. I was not able to find a single corroborating source on the net. If anyone has information about this, either to corroborate their former existence or to debunk them as a myth, it would be a valuable addition to this article. Hzoi 09:06, 6 September 2007 (UTC)