MAMMAL PHYLOGENY, WHAT'S HAPPENING?

[darren.naish@port.ac.uk]

Just a few quick comments on the recent posts about new theories in 
mammalian phylogeny.

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.

DARREN NAISH
darren.naish@port.ac.uk