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Re: Condylarths (TINGAMARRA REVISITED)
> Ken Kinman writes:
> > Well I'll agree that Ungulata is probably polyphyletic. But who
> >put zhelestids outside of Placentalia?
> This is a huge surprise to me too! David, please, what is your source?
No paper is yet published, but:
M. J. Novacek: New eutherian mammal from the Late Cretaceous of Mongolia and
its bearing on the origins of the modern placental radiation, JVP 20(3) SVP
Meeting Abstracts September 2000, p. 61A
"A new eutherian mammal has been recovered from [...] has a strikingly
bunodont dentition. Associated with the maxilla is a left exoccipital, and
incomplete postcrania. The teeth show diagnostic eutherian traits. However,
these teeth contrast with the sectorial cheek teeth that characterize most
Cretaceous eutherians from Central Asia, including the Asioryctitheria and
the Zalambdalestidae. The molars are [...] most like the molars of
zhelestids, particularly *Parazhelestes* and *Eoungulatum*, from the
Coniacian [oho!] of Uzbekistan. The only other mammal from Red Rum
[Kholboot] is a zalambdalestid, represented by two damaged skulls and
several fragmentary jaws and postcrania. Nonetheless, the broad dimensions
of the heavily worn cheek teeth in these fossils closely resemble the new
dentition and seem notably different from the transverse cheek teeth of
described zalambdalestids. This suggests the possibility that the new
dentition is assignable to a new taxon of zalambdalestid. Such an assignment
in combination with the striking dental similarity between the Red Rum taxon
and zhelestids suggests that the latter, which are presently unknown from
skulls, are closely related to zalambdalestids. This argument would either
undermine the proposed affinity between zhelestids and ungulates, or
indicate a close affinity of a zhelestid-zalambdalestid clade with
ungulates. Acceptance of the first hypothesis, which we favor, would
_ELIMINATE ALL EVIDENCE_ for the presence of ungulates or other members of
the crown group Placentalia in the Mesozoic of Asia [my emphasis]. This
further underscores the discrepancy between fossil evidence and molecular
clock estimates for the placental radiation."
BTW, the same issue has an abstract about the K-T:
John W. Hoganson: Additional evidence for the extinction of cartilaginous
fish at the end of the Cretaceous from the marine Breien Member
(Maastrichtian) of the Hell Creek Formation, North Dakota. p. 49A
Confirms J. D. Archibald's findings that all cartilaginous fish died out
there at the K-T, and later in the Paleocene other species immigrated.
> >Are you also
> >saying that Kennalestids, Cimolestids, and Leptictids are are not
> >crown-group placentals??
Well, I don't know. Are Leptictidae known from the Cretaceous (not something
like the Bug Creek Formation, I mean)?
Where is *Kennalestes* put? Somewhere near *Zalambdalestes* (I'm purely
guessing), which is outside Placentalia?
Guillermo W. Rougier, John R. Wible & Michael J. Novacek: Implications of
*Deltatheridium* specimens for early marsupial history, Nature 396, 459 --
463 (3 December 1998) shows Eutheria as (*Prokennalestes* + (*Otlestes* +
(Asioryctitheres + Placentals))) (and all Mesozoic metatherians outside
Marsupialia). This is probably all I have.
> David may mean that these familes do not belong to any extant order. This
> AFAIK is true.
Sure, but this alone doesn't mean much.