Talk:Mesonychid
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[edit] Order or suborder
I have reverted a recent change on Andrewsarchus mongoliensis where Mesonychia was listed as a suborder of Artiodactyla. There are two competing hypothesis concerning the nearest relatives of Mesonychia. The traditional morphological view suggests that they are related to whales. Under this view either Mesonychia, Cetacea, and Artiodactyla are separate orders, the order Cetacea (or Cete as seen in McKenna and Bell, 1997) includes a suborder Mesonychia, or Mesonychia is a suborder of Cetartiodactyla, an order uniting whales and artiodactyls.
Alternatively, recent molecular and morphological work suggests that whales evolved from within the "artiodactyls" and Mesonychia represents a close relative but a distinct group. Under this view either Mesonychia and Cetartiodactyla are distinct orders, or Mesonychia is the most basal suborder within the Cetartiodactyla. To my knowledge no authorities argue that the mesonychids are more closely related to artiodactyls than to cetaceans.
I think recognizing Mesonychia as a distinct order is consistent with any of these hypotheses for relationships and would be the most appropriate position for us to take. Alternatively, it could be treated as a suborder of Cete (Cetacea) if we accept the old morphological hypothesis, but I don't think that's the mainstream approach since the publication of the molecular findings. --Aranae 21:59, 11 October 2005 (UTC)
