The braincases of two glyptosaurines (anguidae, Squamata) and anguid phylogeny (2008)
Jack L. Conrad, Mark A. Norell
Glyptosaurines are an extinct clade of anguids whose remains are common in many Holarctic Paleogene and Cretaceous deposits. Despite their extensive fossil record (comprised mainly of scutes) the...
The Geology of Ukhaa Tolgod (Djadokhta Formation, Upper Cretaceous, Nemegt Basin, Mongolia) (2008)
Lowell Dingus, David B. Loope, Demberlyin Dashzeveg, Chuluun Minjin, Michael J. Novacek, ...
The lithostratigrahy and sedimentology of the fossiliferous Upper Cretaceous strata exposed in the Gobi Desert of Mongolia at Ukhaa Tolgod are described and mapped on aerial photos. Topographic...
Mark A. Norell, Ke-Qin Gao, Jack Conrad
Here we describe a new diminutive varanoid from the Late Cretaceous Djadoktha Formation of Omnogov, Mongolia. The new taxon, Ovoo gurval, was found in the Nemegt Basin at the locality of Little...
Uncertainty in the Age of Fossils and the Stratigraphic Fit to Phylogenies (2006)
The ages of first appearance of fossil taxa in the stratigraphic record are inherently associated to an interval of error or uncertainty, rather than being precise point estimates. Contrasting this...
JULIA A. CLARKE, MARK A. NORELL, DEMBERELYIN DASHZEVEG
A well-preserved nearly complete avian tarsometatarsus was collected by the 2002 expedition of the Mongolian Academy of Sciences from upper Eocene deposits exposed at the locality of Alag Tsav in the...
WALTER G. JOYCE, MARK A. NORELL
The Late Cretaceous continental deposits of Ukhaa Tolgod, Mongolia, have yielded remains of a new nanhsiungchelyid turtle, Zangerlia ukhaachelys, n.sp. This taxon is based on a single individual that...
A New Choristodere from the Cretaceous of Mongolia (2005)
DANIEL T. KSEPKA, KE-QIN GAO, MARK A. NORELL
The remains of a choristodere recently discovered at Two Volcanoes, a new locality in the Gobi Desert of Mongolia, are described in this paper. Consisting of a fairly complete skull and partial...
Although dinosaur fossils are common in the Early Cretaceous strata of Öösh, remains of other vertebrates are rare. Here we describe the first pterosaur fossil known from this locality. The...
A New Gobiosuchid Crocodyliform Taxon from the Cretaceous of Mongolia (2004)
We describe a new fossil crocodyliform, Zaraasuchus shepardi, found in the Cretaceous Red Beds of Zos Canyon (Gobi Desert, Mongolia). Z. shepardi shares numerous derived characters with Gobiosuchus...
A New Crocodyliform from Zos Canyon, Mongolia (2004)
Here we report on a new fossil crocodyliform from Cretaceous Redbeds in the Zos Canyon, Gobi Desert, Mongolia. This new taxon, Zosuchus davidsoni, is described based on the information provided by...
A Troodontid Dinosaur from Ukhaa Tolgod (Late Cretaceous Mongolia) (2004)
MARK A. NORELL, SUNNY H. HWANG
Here we describe a fragmentary troodontid specimen from the sublocality of Grangers Flats at the Late Cretaceous locality of Ukhaa Tolgod, Omnogov, Mongolia. This specimen is provisionally referred...
JULIA A. CLARKE, MARK A. NORELL
Small vertebrates have remained relatively poorly known from the Nemegt Formation, although it has produced abundant and well-preserved large dinosaur remains. Here we report three new avialan...
Ornithomimosaur Cranial Material from Ukhaa Tolgod (Omnogov, Mongolia) (2004)
DANIEL T. KSEPKA, MARK A. NORELL
The 1998 American Museum of Natural History–Mongolian Academy of Sciences expedition uncovered partial ornithomimosaur remains from the Xanadu sublocality at Uhkaa Tolgod. The specimen includes the...
An Early Ostrich Dinosaur and Implications for Ornithomimosaur Phylogeny (2003)
QIANG JI, MARK A. NORELL, PETER J. MAKOVICKY, KE-QIN GAO, SHU'AN JI, CHONGXI YUAN
A new ornithomimosaur from the Yixian Formation of Liaoning Province People's Republic of China is described. These beds are near the Jurassic-Cretaceous boundary. This specimen is interesting...
MARK A. NORELL, WARD C. WHEELER
Almost all phylogenetic studies utilizing fossils are faced with the problem of missing data. With the development of methods allowing total evidence phylogenies where fossils are combined with...
Osteology and Relationships of Byronosaurus jaffei (Theropoda: Troodontidae) (2003)
PETER J. MAKOVICKY, MARK A. NORELL, JAMES M. CLARK, TIMOTHY ROWE
The troodontid Byronosaurus jaffei is known from two specimens from adjacent localities in the Nemegt basin, Ömnögov Aimag, Mongolia. These specimens are composed of well-preserved cranial material...
ROBERT V. HILL, LAWRENCE M. WITMER, MARK A. NORELL
Here we report the occurrence of a juvenile ankylosaur from the Upper Cretaceous locality Ukhaa Tolgod in southern Mongolia. The locality is well known for its exquisitely preserved theropods,...
JULIA A. CLARKE, MARK A. NORELL
The avialan taxon Apsaravis ukhaana from the Late Cretaceous of southern Mongolia is completely described and its phylogenetic position is evaluated. Apsaravis ukhaana is from continental sandstones...
New Specimens of Microraptor zhaoianus (Theropoda: Dromaeosauridae) from Northeastern China (2002)
SUNNY H. HWANG, MARK A. NORELL, JI QIANG, GAO KEQIN
New specimens of the diminutive theropod dinosaur Microraptor zhaoianus are described. These specimens preserve significant morphological details that are not present or are poorly preserved in the...
JAMES M. CLARK, MARK A. NORELL, TIMOTHY ROWE
We describe the skull of the holotype of Citipati osmolskae, one of the best preserved oviraptorid skulls known. The skull preserves stapes and epipterygoids, and the mandible preserves a slender...
An Embryonic Oviraptorid (Dinosauria: Theropoda) from the Upper Cretaceous of Mongolia (2001)
MARK A. NORELL, JAMES M. CLARK, LUIS M. CHIAPPE
An embryonic oviraptorid skeleton is described within an egg from the Late Cretaceous Djadokha Formation of Ukhaa Tolgod, Mongolia. The specimen comprises the ventral part of the skull and most of...
Upper Cretaceous deposits at Ukhaa Tolgod and adjacent localities in the Mongolian Gobi Desert have yielded a large number of superbly preserved lizard specimens, including representatives of several...
Chiappe, Luis M., Ji, Shu-An., Ji, Qiang., Norell, Mark A.
89 p. : ill., map ; 26 cm.
Novacek, Michael J., Ferrusquia-Villafranca, Ismael., Wyss, Andre R., Norell, Mark A.
88 p. : ill. (1 col.), maps ; 26 cm.
Thesis (Ph.D.)--Yale University, 1988.
Nesbitt, Sterling J, Norell, Mark A
Living archosaurs comprise birds (dinosaurs) and crocodylians (suchians). The morphological diversity of birds and stem group dinosaurs is tremendous and well-documented. Suchia, the archosaurian...
Prey choice and cannibalistic behaviour in the theropod Coelophysis
Nesbitt, Sterling J, Turner, Alan H, Erickson, Gregory M, Norell, Mark A
Direct evidence of prey choice in carnivorous dinosaurs is rare in the fossil record. The most celebrated example pertains to purported stomach contents in the carnivorous dinosaur Coelophysis bauri,...
Erickson, Gregory M, Curry Rogers, Kristina, Varricchio, David J, Norell, Mark A, Xu, Xing
The timing of sexual maturation in non-avian dinosaurs is not known. In extant squamates and crocodilians it occurs in conjunction with the initial slowing of growth rates as adult size is...
Avian-like breathing mechanics in maniraptoran dinosaurs
Codd, Jonathan R, Manning, Phillip L, Norell, Mark A, Perry, Steven F
In 1868 Thomas Huxley first proposed that dinosaurs were the direct ancestors of birds and subsequent analyses have identified a suite of ‘avian’ characteristics in theropod dinosaurs. Ossified...