Cedrorestes crichtoni is a genus of iguanodontian dinosaur from the Early Cretaceous of Utah. It is based on an incomplete skeleton which was found in the Barremian age of the Cedar Mountain Formation. The type species is Cedrorestes crichtoni.
Discovery and history[]
The holotype (DMNH 47994) is a partial skeleton including rib fragments, a sacrum, the left ilium and a portion of the right, a right thighbone, the right third metatarsal, and fragments of ossified tendons. These remains were recovered from near the top of the Yellow Cat Member of the Cedar Mountain Formation, in east-central Utah. They were found scattered in a calcareous mudstone, and showed evidence of pre-burial damage, from weathering or trampling.[1]
This genus can be told apart from other iguanodontian ornithopods by its combination of a tall ilium, as is present in Iguanadon-like ornithopods, with a large lateral bony process above and behind the acetabulum and joint surface for the ischium, as is seen in hadrosaurids. David Gilpin and his coauthors, who described the specimen, noted that the lateral process has been considered diagnostic for hadrosaurids,[1][2] and interpreted the combination of anatomical characteristics in Cedrorestes as evidence that the genus was close to the division between hadrosaurids and iguanodontids. They placed their new genus in Hadrosauridae, as the earliest known hadrosaurid.[1]
The etymology of the generic name is, from Latin, cedrus after the Cedar Mountain formation, where the fossil was found + Greek suffix ending -etes; "dweller". The specific epithet crichtoni is after Michael Crichton, author of Jurassic Park and The Lost World. Other dinosaurs named after Michael Crichton is Crichtonsaurus and Crichtonpelta[1]
Paleoecology and paleobiology[]
The Yellow Cat Member of the Cedar Mountain Formation is known for its dinosaurs, including the small coelurosauriantheropod Nedcolbertia, the dromeosaurid Utahraptor, brachiosaurid sauropod Cedarosaurus, and heavily armored ankylosaurid Gastonia.[3]
Whether a basal hadrosaurid or derived non-hadrosaurid iguanodontian, Cedrorestes would have been a large herbivore capable of moving both bipedally or on all fours.[4][5] The structure of its hip indicates that it had hadrosaurid-like leg muscles, but the functional significance of the changes in leg muscles from the iguanodontian layout to the hadrosaurid layout, and resulting differences in movement (if any), are not yet understood.[1] Detailed interpretations of the paleobiology of Cedrorestes must wait for the discovery of more extensive remains.
Gallery[]
