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Re: Therizinosauroid apomorphies
From: "Timothy Williams" <firstname.lastname@example.org>
To: email@example.com, firstname.lastname@example.org
Subject: Re: Therizinosauroid apomorphies
Date: Mon, 03 Apr 2000 16:17:00 EDT
True, some therizinosaur characters are characteristic of sauropodomorphs
(e.g. foot, pelvis - especially the ilium).
From what I can tell of _Alxasaurus_ and _Beipiaosaurus_, the ilium is not
very like that of other therizinosauroids where the ilium is known. In fact
the ilium of _Beipiaosaurus_ is described as unlike that of other
therizinosauroids by its describers.
therizinosaurs are NOT sauropodomorphs but theropods,
I've come to agree with you here, but I don't know that they form a
monophyletic group within theropods.
True, some other characters are characteristic of ornithischians (e.g.
mandible, with the lateral "shelf" and inset tooth row - suggestive of
"cheeks"; opisthopubic pelvis, also seen in eumaniraptorans).
Point well taken.
There are a whole lot of good apomorphic therizinosaur characters seen in
the skull and postcranium of these beasties, including morphology of the
humerus and (as George mentioned) the distinctive, laterally-compressed,
The claw character isn't that great. It seems mostly to characterize
So far, though, my list has grown to at least two good diagnosing
1. Mandibular shelf
2. Humerus with large internal tubercle.
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