recently extinct groups

["A.P. Hazen" <a.hazen@philosophy.unimelb.edu.au>]

Tommy Tyrberg wrote:
	"There are actually quite a few extinct high-level taxa
	that are potentially within range for sequencing, i e became
	extinct in the Late Pleistocene or Holocene. These are
	the ones I can think of:"
with a list of Theropod taxa (that gets a dinosaur reference into 
this post!) and the mammal "families":
Diprotodontidae
Thylacoleonidae
Palorchestidae
.
Megatheriidae
Mylodontidae
.
Macraucheniidae
Toxodontidae
Mesotheriidae
.
Gompotheriidae
Mammutidae
Stegodontidae
   The  first  three are Australian  marsupials: I think people would 
be very surpised if molecular evidence didn't show tham all to  be 
diprotodontian (that is, closer to  kangaroos, wombats and Australian 
possums than to, say, dasyuromorphs).  The next two are Xenarthrans, 
"ground sloths" by ecotype: I assume no one would expect them not to 
be closer to living tree-sloths than to, say, armadillos.  The next 
three are South American endemic "ungulates":  I share Tyrberg's 
sense that these might be the most interesting from a phylogenetic 
perspective.  The last three are Proboscidean, and I think  thre is a 
general view about their relationships (among themselves and  to the 
living  Elephantidae) that most proboscideologists would be VERY 
surprised to find  contradicted.
   Another taxon from the  Holocene  about which serious 
phylogenetic doubts have arisen is Paleoycteropus: originally 
described as a Tubulidentate (as the  name suggests), but 
subsequently argued  to be "ordinally" distinct from all other known 
mammals (and given its own "order", Bibimalagaysia).
   (I have put scare quotes around terms that devout cladists might 
find objectionable.)

Allen Hazen
Philosophy Department
University of Melbourne