Talk:Miacids

From Wikipedia, the free encyclopedia

	Mammals Portal This article is within the scope of WikiProject Mammals, a project to improve Wikipedia's articles on Mammal-related subjects. Please participate by editing the article, and help us assess and improve articles to good and 1.0 standards, or visit the wikiproject page for more details.
Start	This article has been rated as start-class on the quality scale.
Low	This article has been rated as Low-importance on the importance scale.
	This article has been marked as needing immediate attention.
Assessment comments This article has been rated for quality and/or importance but has no comments yet. If appropriate, please review the article and then leave comments here to identify the strengths and weaknesses of the article and what work it will need.

[edit] Classification

New studies suggest that "Miacidae represents a paraphyletic array of stem taxa, basal to the Carnivora." See: Flynn, John J. and Gina D. Wesley-Hunt. (2005). “Phylogeny of the Carnivora: Basal Relationships Among the Carnivoramorphans, and Assessment of the Position of ‘Miacoidea’ Relative to Carnivora.” Journal of Systematic Paleontoly, Vol. 3, pp. 1-28. http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=285902 Valich 17:52, 13 February 2007 (UTC)

The Wikipedia Miacid article and [Carnivora]] article classifications need to be rewritten and regrouped to be more in accord with each other but it is difficult because of the evolutionary age distinctions. A major problem is the layman's association of carnivores with carnivora: carnivore does not equal carnivora. The first mammalian "meat eaters" were the Creodonta followed by Carnivoramorpha (an article to be written) and then the Carnivora. The Carnivoramorpha (basal to Carnivora) evolved into the Miacoidea†-Miacoid Group (65-45 Ma), that then split into two groups: Miacidae (paraphyletic) and Viverravidae. Traditionally, the Miacidae and the Viverravidae have been classified in the superfamily Miacoidea, from which the direct ancestors of the other two superfamilies arose. The Miacidae evolved into the Caniformia (Caniforms), so the ranking now is: Order Carnivora, Superfamily Miacoidea, Family Miacidae; then Suborder Caniformia. I think it should be "Order" Carnivoramorpha instead of Carnivora. The Amphicyonids were the first of the Caniforms to split off. The divergence age of the subclades Caniformia and Feliformian occurred during the Mid-Eocene (~43 mya).

I'm not sure how to reconcile this. The problem is that we're dealing with three distinct carnivore groups (Creodonts, Carnivoramorpha, and Carnivora) that existed in overlapping multiple-epoch time periods, but we have to stick to the 7 taxonomic levels, else it would get too complicated. A family in one order and a family in another order can be at a different level in terms of evolutionary timescale, so the classification has to be viewed in its context. Nevertheless, we have to strive for some consistency, or else make this context clear in the article for better understanding and no confusion.

Pinnipedia (Pinnipeds) derived from a common bearlike ancestor from the Caniformia group during the late Oligocene Epoch (~30-34 Ma), diverging ~25-27 Ma into the 3 families: Odobenidae (walruses), Otariidae (sea lions), and Phocidae (seals). "The pinnipeds are part of a clade, known as the Arctoidea, which also includes the bears and the superfamily Musteloidea. The Musteloidea in turn consists of the mustelids, procyonids, skunks and Ailurus. The dogs are the sister group to the entire arctoid assemblage; they were the first of the extant caniforms to split from the others." Valich 05:00, 15 February 2007 (UTC)