Cedrorestes

Taxobox|
name = "Cedrorestes"
fossil_range = Early Cretaceous
regnum = Animalia
phylum = Chordata
classis = Sauropsida
superordo = Dinosauria
ordo = Ornithischia
subordo = Ornithopoda
infraordo = Iguanodontia
superfamilia = Hadrosauroidea
familia = ?Hadrosauridae
genus = "Cedrorestes"
genus_authority = Gilpin "et al"., 2007
subdivision_ranks = Species
subdivision =
* "C. crichtoni" (type)

"Cedrorestes" (meaning "Cedar mountain dweller", in reference to its discovery in the Cedar Mountain Formation) is a genus of possible basal hadrosaurid dinosaur from the Early Cretaceous of Utah. It is based on an incomplete skeleton which was found in the Barremian-age Yellow Cat Member of the Cedar Mountain Formation.

Discovery and history

"Cedrorestes" is based on DMNH 47994, 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.cite book |last=Gilpin |first=David |coauthors=DiCroce, Tony; and Carpenter, Kenneth |year=2007 |chapter=A possible new basal hadrosaur from the Lower Cretaceous Cedar Mountain Formation of Eastern Utah |editor=Carpenter, K. (ed.) |title=Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs |publisher=Indiana University Press |location=Bloomington and Indianapolis |pages=79-89 |isbn=0-253-34817-X]

This genus can be told apart from other iguanodontian ornithopods by its combination of a tall ilium, as is present in "Iguanodon"-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,cite book |last=Weishampel |first=David B. |authorlink=David B. Weishampel |coauthors=and Horner, Jack R. |editor= Weishampel, David B.; Osmólska, Halszka; and Dodson, Peter (eds.)|title=The Dinosauria |edition=1st |year=1990 |publisher=University of California Press |location=Berkeley |isbn=0-520-06727-4 |pages=534-561 |chapter=Hadrosauridae] 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.

The etymology of the generic name is, from Latin, "cedrus" ("cedr-"); "cedar" + Greek "oros-"; "mountain", 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".

Paleoecology and paleobiology

The Yellow Cat Member of the Cedar Mountain Formation is known for its dinosaurs, including the small coelurosaurian theropod "Nedcolbertia", the dromaeosaurid "Utahraptor", brachiosaurid sauropod "Cedarosaurus", and heavily armored ankylosaurid "Gastonia".cite book |last=Weishampel |first=David B. |authorlink=David B. Weishampel |coauthors=Barrett, Paul M.; Coria, Rodolfo A.; Le Loeuff, Jean; Xu Xing; Zhao Xijin; Sahni, Ashok; Gomani, Elizabeth, M.P.; and Noto, Christopher R. |editor=Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.)|title=The Dinosauria |edition=2nd |year= 2004|publisher=University of California Press |location=Berkeley |isbn=0-520-24209-2 |pages=517-606 |chapter=Dinosaur Distribution ]

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.Horner, John R.; Weishampel, David B.; and Forster, Catherine A. (2004). "Hadrosauridae". The Dinosauria, 2nd edition. 438–463.] cite book |last= Norman|first=David B. |editor= Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.)|title=The Dinosauria |edition=2nd |year= 2004|publisher=University of California Press |location=Berkeley |isbn=0-520-24209-2 |pages=413–437 |chapter=Basal Iguanodontia] 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. Detailed interpretations of the paleobiology of "Cedrorestes" must wait for the discovery of more extensive remains.

References

External links

* [http://dml.cmnh.org/2006Nov/msg00073.html Dinosaur Mailing List entry which announces the discovery]