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Re: Reduced Consensus (Was: Afrotheria revisited)



Mickey Mortimer wrote:

I have a hard time imagining how mammalogists don't go insane with so many major groups of mammals that have utterly unknown relationships. That never happens with dinosaurs.

Well, not the <non-avian> ones, anyway. ;-)

Neornithean relationships are a total mess. Despite (or maybe because of) molecule-based phylogenies.

But mammalogists have asioryctitheres, leptictids, anagaloids, zhelestids, dinoceratans, xenungulates, astrapotheres, litopterns, notungulates, arctostylopids, etc. etc.. Madness.

There is hope, but it's a war of attrition. Many studies on placental relationships are very narrowly focused - not just in the number of taxa that are covered, but also in that these studies tend to focus only on certain parts of the skeleton. Apart from the study you discussed, there's also (for example) a recent study which proposed that arctostylopids were related to Glires based principally on tarsal morphology (Missiaen et al., 2006; Naturwissenschaften 93: 407-411). I'm not saying that this is necessarily a bad idea, because it leads to some very interesting hypotheses. However, those same hypotheses can only be rigorously tested in the context of much larger phylogenetic analyses. The latter throw the net much wider by including more anatomical characters drawn from a larger spectrum of taxa. This ensures that competing phylogenetic hypothese are implicitly tested.


Cheers

Tim

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