I've removed Category:Mammals from this template because it was making proper subcategorization impossible. As a general rule, it's a bad idea to include categories in templates because that automatically applies the category to any article to which the template is applied, without any possibility of editing it off an individual article without removing the template. Animals that have been categorized as members of a subgroup of mammals (such as Category:Marsupials) should not be redundantly grouped in the parent category as well (unless it is the article that defines the subgroup, such as marsupial). Postdlf 23:04, 25 Mar 2005 (UTC)
The older discussion from MediaWiki talk:Mammals, which I deleted, can be found here. --Ixfd64 19:21, 25 November 2005 (UTC)[reply]
Should extinct orders be added to the table? GCarty 09:55, 12 January 2006 (UTC)[reply]
Can anyone cite any legitimate reference anywhere that uses "Subclass Marsupialia" or "Subclass Placentalia"? --Aranae 03:24, 18 September 2006 (UTC)[reply]
Please see my comment at Talk:Prototheria. --Mathew5000 21:40, 25 August 2007 (UTC)[reply]
How come the template has reverted back from Australosphenida to Prototheria? Monotremes currently have no generally agreed subclass assignation. Australosphenida may still be controversial, but Prototheria is multiply ambiguous and obsolete. That is, it has had so many now-falsified uses that for practical purposes it can be considered defunct unless and until somebody can come up with a justification for its existence.
Admittedly, grouping by infraclasses wasn't perfect either: Australosphenida is often simply unranked, and the recent classifications like McKenna/Bell insert so many new nodes that they downgrade Theria, Metatheria and Eutheria to well below subclass or infraclass status. I don't know what the solution is, but Wikipedia generally follows Michael J. Benton's Vertebrate Palaeontology for the higher-level classification of vertebrates, and he shovels nearly everything mammalian into Subclass Mammaliformes—Infraclass Holotheria, but further down he has Superdivision Australosphenida—Division Monotremata, contrasting with Superdivision Theriimorpha—Division Theriiformes, the last of which includes Theria (as an infralegion), comprising Cohorts Marsupialia and Placentalia. Why not go with divisions and cohorts instead of subclasses and infraclasses? And leave Prototheria aside. Gnostrat (talk) 14:35, 25 June 2008 (UTC)[reply]
When you go with the template for rodents, extinct families will be shown. I think that everyone should help putting in the extinct mammalian orders if they want to, I already put a few.545lljkr (talk) 02:40, 22 October 2008 (UTC)[reply]