A primitive therizinosauroid dinosaur from the Early Cretaceous of Utah.
Nature
; 435(7038): 84-7, 2005 May 05.
Article
em En
| MEDLINE
| ID: mdl-15875020
ABSTRACT
Therizinosauroids are an enigmatic group of dinosaurs known mostly from the Cretaceous period of Asia, whose derived members are characterized by elongate necks, laterally expanded pelves, small, leaf-shaped teeth, edentulous rostra and mandibular symphyses that probably bore keratinized beaks. Although more than a dozen therizinosauroid taxa are known, their relationships within Dinosauria have remained controversial because of fragmentary remains and an unusual suite of characters. The recently discovered 'feathered' therizinosauroid Beipiaosaurus from the Early Cretaceous of China helped to clarify the theropod affinities of the group. However, Beipiaosaurus is also poorly represented. Here we describe a new, primitive therizinosauroid from an extensive paucispecific bonebed at the base of the Cedar Mountain Formation (Early Cretaceous) of east-central Utah. This new taxon represents the most complete and most basal therizinosauroid yet discovered. Phylogenetic analysis of coelurosaurian theropods incorporating this taxon places it at the base of the clade Therizinosauroiden, indicating that this species documents the earliest known stage in the poorly understood transition from carnivory to herbivory within Therizinosauroidea. The taxon provides the first documentation, to our knowledge, of therizinosauroids in North America during the Early Cretaceous.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Esqueleto
/
Dinossauros
/
Fósseis
Limite:
Animals
País/Região como assunto:
America do norte
Idioma:
En
Revista:
Nature
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Estados Unidos