[D] Amtosaurus archibaldi [Su]
Cretaceous Late Turonian Coniacian
Ornithischia Thyreophora Eurypoda Ankylosauria Ankylosauridae
Bissekt Formation, Dzharakuduk, Uzbekistan
Bissektipelta archibaldi (Parrish & Barrett, 2004) > Amtosaurus archibaldi (Averianov, 2002)
Known material, braincase, teeth, osteoderms.
Holotype: ZIN PH 1/6, nearly complete braincase. Discovered in September 1998 by Oleg Turuk during field work of the joint Usbek-Russian-Britisch-American-Project (URBAC-98).
Diagnosis: Differing from Amtosaurus magnus in having three (rather than two) exits for N. hypoglossus (XII), smaller angle between ventral surfaces of basisoccipital and basisphenoid (90 degrees rather than 120 degrees), and more caudally placed basispterygoid processes (Averianov, 2002)
Parrish & Barrett, 2004 pointed out that Amtosaurus magnus should be regarded a nomen dubium as Ornithischia indeterminate. However, they regarded A. archibaldi as a valid taxon, characterized by an autapomorphic feature of the skull roof, and they refered this species to the new genus Bissektipelta.