[D] Zupaysaurus rougieri [Su] [sG] [T]
Describer
Arcucci and Coria, 2003
Time
Triassic Late Rhaetian Hettangian
Classification
Saurischia Theropoda Tetanurae
Diet
Carnivore
Fossilsite
Los Colorados Formation, La Rioja Province, Argentina
Info
Genus - Typespecies - Skull
Holotype: PULR-076, including a nearly complete skull (estimated total length: 45cm), several vertebrae (representing presacral and sacral series), and fragmentary limb material. The name; Zupaysaurus derives from \\\\\\\'zupay\\\\\\\', meaning \\\\\\\'devil\\\\\\\' in the Quechua native language. The species name honors Dr Guillermo Rougier.
The most prominent feature of the skull is the paired parasagittal crests, formed exclusively from the nasals (not the nasals and lacrimals, as in coelophysoids). These were very thin. Additional cranial ornamentation is expressed in the form of a rugose, laterally-projecting lacrimal ridge.
The premaxilla is not known, but the maxilla has a conspicuous step at its anterior edge. The maxilla bears an alveolar ridge (apparently a primitive theropod feature; it is also seen in Eoraptor and [coelophysids]). The antorbital fenestra is oval-shaped, and the fossa very large (> 25%), and the maxilla tooth row ends in front of the orbit. The dentition is poorly preserved, though the fourth maxilary tooth is the largest. The authors estimate up to 24 four teeth in the jaws (15 in the maxilla). The lower jaw shows an intramandibular hinge.
The neck of Zupaysaurus was rather long, based on the length of the cervical centra. The tibia is trasversely expanded distally, as in tetanurans. The astragalus and calcaneum are fused to each other, but not to the tibia; and the astragalus has an anteriorly positioned ascending process. Arcucci and Coria propose Zupaysaurus as the most primitive known tetanuran theropod.
Arcucci and Coria, 2003
Time
Triassic Late Rhaetian Hettangian
Classification
Saurischia Theropoda Tetanurae
Diet
Carnivore
Fossilsite
Los Colorados Formation, La Rioja Province, Argentina
Info
Genus - Typespecies - Skull
Holotype: PULR-076, including a nearly complete skull (estimated total length: 45cm), several vertebrae (representing presacral and sacral series), and fragmentary limb material. The name; Zupaysaurus derives from \\\\\\\'zupay\\\\\\\', meaning \\\\\\\'devil\\\\\\\' in the Quechua native language. The species name honors Dr Guillermo Rougier.
The most prominent feature of the skull is the paired parasagittal crests, formed exclusively from the nasals (not the nasals and lacrimals, as in coelophysoids). These were very thin. Additional cranial ornamentation is expressed in the form of a rugose, laterally-projecting lacrimal ridge.
The premaxilla is not known, but the maxilla has a conspicuous step at its anterior edge. The maxilla bears an alveolar ridge (apparently a primitive theropod feature; it is also seen in Eoraptor and [coelophysids]). The antorbital fenestra is oval-shaped, and the fossa very large (> 25%), and the maxilla tooth row ends in front of the orbit. The dentition is poorly preserved, though the fourth maxilary tooth is the largest. The authors estimate up to 24 four teeth in the jaws (15 in the maxilla). The lower jaw shows an intramandibular hinge.
The neck of Zupaysaurus was rather long, based on the length of the cervical centra. The tibia is trasversely expanded distally, as in tetanurans. The astragalus and calcaneum are fused to each other, but not to the tibia; and the astragalus has an anteriorly positioned ascending process. Arcucci and Coria propose Zupaysaurus as the most primitive known tetanuran theropod.