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Re: utahraptor conemporaries and more



Lewis LaRosa wrote-

> can anyone give me a little info on utahraptor's environment? it's
> contemporaries? i need help for a series of illustrations. if you have any
> links or photos please e-mail me.

Yellow Cat Member of Cedar Mountain Formation (Barremian)
Nedcolbertia justinhofmanni
Richardoestesia sp. (Kirkland and Parrish 1995)
Utahraptor ostrommaysorum
undescribed Camarasaurid (Britt, Stadtman, Scheetz and McIntosh 1997)
Cedarosaurus weiskopfae
undescribed Titanosaurid (Britt, Stadtman, Scheetz and McIntosh 1997)
Gastonia burgei
undescribed Polacanthid
Sauropelta edwardsi
Iguanodon ottingeri
undescribed Iguanodontid

> can anyone send me info on the unnamed brachiosaur i've heard that
coexisted
> with utahraptor? as well as eolambia, and the unnamed iguanodont,
> ankylosaur, nodosaur, and dromaesaur?

The only brachiosaur from that formation is Cedarosaurus.
Cedarosaurus Tidwell, Carpenter and Brooks 1999
C. weiskopfae Tidwell, Carpenter and Brooks 1999
Barremian, Eearly Cretaceous
Yellow Cat Member of Cedar Mountain Formation, Utah, US
Holotype- (DMNH 39045) (adult) eight dorsal vertebrae (100-260 mm), several
incomplete dorsal ribs, twenty-five caudal vertebrae (92-117 mm), several
chevrons, proximal scapulae, coracoids, sternal plates, humerus (1.38 m),
radius (812 mm), ulna, metacarpal IV (428 mm), pubes, proximal ischia,
femora (1.395 m), tibia (~884 mm), metatarsal I (152 mm), metatarsal II (201
mm), metatarsal V, pedal phalanx II-1, three pedal unguals, gastroliths
Diagnosis- proximal caudal vertebrae with deeply concave anterior faces and
lack well developed hyposphenes, mid-caudalk vertebrae with sharp ridge
extending axially along neural arch, deltopectoral crest placed more
distally than Brachiosaurus, Pleurocoelus and Texas "Pleurocoelus", humerus
more robust than Brachiosaurus,
Description- humerofemoral ratio .98,
Comments- Some material referred to Pleurocoelus belongs to this species.
Reference- Tidwell, Carpenter and Brooks, 1999. "New sauropod from the Lower
Cretaceous of Utah, USA," Oryctos 2: 21-37.

Eolambia lived later, in the Cenomanian.

undescribed Iguanodontid (Kirkland, Lucas and Estep 1998)
Barremian, EC
Yellow Cat Member of Cedar Mountain Formation, Utah, US
Description- sail-backed
Comments- Brooks Britt wrote (1997)- We have collected over 1400 bones at
the Dalton Wells quarry near Moab and have found no evidence of more then
one ornithopod.  We consideer the maxilla with teeth described by Galton and
Jensen as Iguanodon ottingeri to be a juvenile.  We have elements of at
least two adult individuals showing I. ottingeri attained a length of 30
feet.  The Dalton Wells taxon differs from the european Iguanodons and shows
some similarities to Iguanodon lakotaensis, but the details remain to be
worked out.  I received a sizeable grant from the Dinosaur Society to
conduct two months of field work and research trips this year and hope to
have more details in the near future.

I've never heard of any ankylosaurids from the Yellow Cat Member, nor any
unnamed nodosaurids or dromaeosaurids.

> were acrocanthosaurus, astrodon, and euhelopus contemporaries? if so, i'd
> appreciate any information on astrodon and euhelopus as well as links or
> photos of fossils or skeletal reconstructions.

No.  Acrocanthosaurus and Astrodon/Pleurocoelous lived later
(Aptian-Albian), while Euhelopus lived earlier (Kimmeridgian?) in China.

> also, regarding utahraptor, the few bits of the skull that were found that
> i've seen are from the dentary. how does the morphology of the skull
compare
> to deinonychus, velociraptor and other dromaesaurs? is the skull deeper?
is
> it upturned or does it slope down as deinonychus' apparently did?

Actually, no dentary remains are known.  All we have is the premaxilla,
nasal and quadratojugal.  Of these only the premaxilla has been described.
Judging the shape of the skull solely based on this, it may have been low
like Velociraptor's, but not as elongate.

Mickey Mortimer