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MAMMAL PHYLOGENY, WHAT'S HAPPENING?
Just a few quick comments on the recent posts about new theories in
Be aware that many of the very strange new groupings (e.g.
chrysochlorid + tethythere + tubulidentate clade) have previously
been proposed by de Jonks and others in review papers (e.g. there was
a good one in _TREE_ in '98) and are based predominantly on molecular
characters. A lot of this stuff is under heavy fire.
Hedgehogs outside placentals is not likely on the morphological
evidence: erinaceomorphs have good insectivoran characters that
include the unique absence (!) of the jugal (Butler (1988) in
Benton _Phylogeny of the Tetrapods Vol. II_). But then, molecules vs.
morphology.. hardly an unfamiliar debate is it?
Thewissen and Madar's new paper on primitive cetacean ankles is not
the first report of this discovery, as they covered it in _Nature_
395 (together with Hussain) last year. Taking bats out of Archonta is
doubtless going to be very controversial (though it has been
contested before - Honeycutt and Adkins in their _Ann. Revi. Earth
Planet. Sci._ overview), but note that Szalay has been vocal about
the reality (or otherwise) of Beard's Primatomorpha clade (see
Szalay and Lucas 1996).
Affinities between pangolins and carnivorans have previously been
noted (I think I recall a mention in Novacek's 'shaking the tree'
(_Nature_ 356)) based on the ontogeny of some lateral braincase
bones. Who knows what South American 'meridiungulates' are..?
Interesting, though, that pyrotheres are uintatheres have been united
by Spencer Lucas as the Pyrotheriamorpha, a clade that may fall into
the anagalidans (so, yes, dinoceratans are 'giant horned bunnies')
(Cifelli (1993) regarded this as unlikely).
Consensus? Not yet I think.