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Condylarths (TINGAMARRA REVISITED)




Darren,
If McKenna and Bell had made a clean break of it, and just abandoned the name Condylartha, we wouldn't have people still tempted to use it as a wastebasket for forms like Tingamarra (which is probably not closely related to any of the old condylarth groups).
That is why I completely abandoned the name Condylarthra. Didolodontiformes as sister group to a Litopterniform-Notounguliform clade. Phenacodontiformes close to both Perissodactyliformes and the whole meridiungulate complex. Mesonychiformes as outgroup to whales, Arctocyoniformes and Hyopsodontiformes further out in the cetartiodactyl complex.
If 5 separate orders is oversplit, so be it, but I thought this was better than dribbling out the cladification process as McKenna seems to be doing (and confusing matters more by holding onto a useless term like Condylarthra). After 7 years, I really need to recode the whole mess and incorporate recent molecular work (and hadn't heard about Bubulodentata), but once I decided Condylarthra was a hopelessly confusing mess, I just completely did away with it.
-----So it goes, Ken
P.S. Thecodontia (Thecodontiformes) is a candidate for demolition, and once I split it, I will abandon the term totally (clean break). Most people think this is overdue, but Condylarthra was far worse in my opinion.
*******************************************************
From: darren.naish@port.ac.uk
Reply-To: darren.naish@port.ac.uk
To: dinosaur@usc.edu
Subject: TINGAMARRA REVISITED
Date: Fri, 18 May 2001 15:15:38 +0100

On metatherians 'vs' placentals, Tim wrote...

> To add to that, a tooth (named _Tingamarra porterorum_) from the early
> Eocene of Murgon in southeastern Queensland, Australia, has been
> regarded as pertaining to a "condylarth".

I deliberately avoided mention of _Tingamarra_ because it's status as a
putative basal ungulate (or condylarth or whatever) is by no means
certain. This I learnt from Tom Rich who mentioned similarities the
specimen has with _Slaughteria_, a basal tribosphenid (or possible
metatherian) from North America.

_Australian Journal of Mammalogy_ (I think) recently ran a huge
multi-author review paper of the Australian mammal fossil record. The
same doubts about _Tingamarra_ were mentioned in there too, though
I forget under which heading _Tingamarra_ was discussed (possibly
the bit at the end about problematica - e.g. Owen's Australian elephants
[_Elephas australis_ etc.]). As usual I'm at university and the paper is
at home.

> I haven't heard anything recently on the affinities of _Tingamarra_,
> especially in light of the "break-up" of the Condylarthra.

Obviously the traditional concept of Condylarthra is in trouble as it's
horribly paraphyletic. McKenna and Bell however recognised a more
restrictive group of this name which includes phenacodontids,
ectoconids, periptychids, mioclaenids and (IIRC) didolodontids.
Didolodontids supposedly share ?tooth characters with basal litopterns
though, so even this doesn't work - - in their introduction McKenna
and Bell do say though that they can accept 'a tolerable amount of
paraphyly' (or something similar). Periptychids and mioclaenids were
recently united in the Bubulodentata by... no, drat, can't remember....
(possibly David Archibold).

"I was going to vote for the Apathy Party, but I just can't be bothered"

DARREN NAISH
PALAEOBIOLOGY RESEARCH GROUP
School of Earth & Environmental Sciences
UNIVERSITY OF PORTSMOUTH
Burnaby Building
Burnaby Road                           email: darren.naish@port.ac.uk
Portsmouth UK                          tel (mobile): 0776 1372651
P01 3QL                                tel (office): 023 92842244
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