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Therizinosauroid dinosaurs from Upper Cretaceous of Uzbekistan

Ben Creisler

A new paper:

Hans-Dieter Sues &  Alexander Averianov (2016) [2015]
Therizinosauroidea (Dinosauria: Theropoda) from the Upper Cretaceous
of Uzbekistan.
Cretaceous Research 59: 155–178


Therizinosauroid dinosaurs are reported from the Cenomanian and
Turonian of Uzbekistan.
Two distinct therizinosauroid morphotypes can be distinguished in the
Bissekty Formation.
They are less derived than the Late Cretaceous therizinosaurids from
Mongolia and China.


Skeletal remains of indeterminate therizinosauroid dinosaurs are
present in the Cenomanian Khodzhakul Formation and common in the
Turonian Bissekty Formation of Uzbekistan. At least two taxa are
present in the Bissekty Formation based on different frontal and
humerus morphotypes. Phylogenetic analysis based on a dataset with 348
morphological characters and including all known therizinosaurian taxa
places the Bissekty taxa as derived non-therizinosaurid
therizinosauroids. The Bissekty therizinosauroids are more derived
than Alxasaurus elesitaiensis in the extensive pneumatization of the
postcranial axial skeleton, the absence of teeth in the anterior
portion of the dentary, the weak development or even absence of pits
for the collateral ligaments on the manual phalanges, and the
subtriangular medial aspect of the distal end of the humerus, with the
entepicondyle positioned well medial to the ulnar condyle. They are
less derived than Therizinosauridae in the presence of a basisphenoid
recess, the absence of pneumatic openings on the anterior caudal
vertebrae, the distal end of metacarpal III not being ginglymoid in
dorsal view, and the separation of the femoral head from the neck of
that bone by a raised ventral rim.