Palynology of the Hell Creek Formation (Upper Cretaceous, Maastrichtian) in northwestern South Dakota: Effects of paleoenvironment on the composition of palynomorph assemblages

2002 ◽  
Author(s):  
Timothy J. Kroeger
Keyword(s):  
South Dakota ◽  
Upper Cretaceous ◽  
Hell Creek Formation

New caenagnathid (Dinosauria: Theropoda) specimens from the Upper Cretaceous of North America and Asia

1993 ◽  
Vol 30 (10) ◽  
pp. 2255-2272 ◽  
Author(s):  
Philip J. Currie ◽  
Stephen J. Godfrey ◽  
Lev Nessov
Keyword(s):  
North America ◽  
South Dakota ◽  
Upper Cretaceous ◽  
New Genus ◽  
Food Type ◽  
New Genus And Species ◽  
Hell Creek Formation ◽  
Central Asian ◽  
Southern Alberta ◽  
Judith River Formation

New specimens of caenagnathid theropods are described from the Judith River Formation (Campanian) of southern Alberta, the Hell Creek Formation (Maastrichtian) of South Dakota, and the Bissekty Formation (Turonian) of Uzbekistan. With the exception of the Hell Creek specimen, and a vertebra from Alberta, all are from the symphysial regions of the lower jaws. Caenagnathids are rare and poorly known animals, and the described fossils preserve heretofore unknown features, including vascular grooves and foramina in the symphysial region, and the pattern of overlapping sutures between jaw elements. Most of the new specimens are different from the holotype of Caenagnathus collinsi Sternberg and may represent the second described species, Caenagnathus sternbergi. The two jaws from the Bissekty Formation are the first oviraptorosaurian jaws described from Uzbekistan and represent a new genus and species anatomically closer to Caenagnathus than to central Asian forms like Oviraptor, Conchoraptor and Ingenia. There are at least five characters that distinguish caenagnathid and oviraptorid jaws, but it is concluded that the length of the symphysial region must be used with caution. Jaw anatomy supports the idea that oviraptorids were well adapted for eating eggs, although their diet was probably not restricted to one food type.

scholarly journals The furculae of the dromaeosaurid dinosaurDakotaraptor steiniare trionychid turtle entoplastra

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1691 ◽  
Author(s):  
Victoria M. Arbour ◽  
Lindsay E. Zanno ◽  
Derek W. Larson ◽  
David C. Evans ◽  
Hans-Dieter Sues
Keyword(s):  
South Dakota ◽  
Upper Cretaceous ◽  
Theropod Dinosaur ◽  
Hell Creek Formation ◽  
Holotype Specimen

Dakotaraptor steiniis a recently described dromaeosaurid dinosaur from the Upper Cretaceous (Maastrichtian) Hell Creek Formation of South Dakota. Included within theD. steinihypodigm are three elements originally identified as furculae, one of which was made part of the holotype specimen. We show that the elements described asD. steini‘furculae’ are not theropod dinosaur furculae, but are rather trionychid turtle entoplastra referable to cf.Axestemys splendida. The hypodigm ofD. steinishould be adjusted accordingly.

scholarly journals The furculae of the dromaeosaurid dinosaur Dakotaraptor steini are trionychid turtle entoplastra

2015 ◽  
Author(s):  
Victoria M. Arbour ◽  
Lindsay E. Zanno ◽  
Derek W. Larson ◽  
David C. Evans ◽  
Hans-Dieter Sues
Keyword(s):  
South Dakota ◽  
Upper Cretaceous ◽  
Skeletal Remains ◽  
Theropod Dinosaur ◽  
Hell Creek Formation ◽  
Holotype Specimen

Dakotaraptor steini is a recently described dromaeosaurid dinosaur from the Upper Cretaceous (Maastrichtian) Hell Creek Formation of South Dakota. Included within the D. steini hypodigm are three elements originally identified as furculae: one which is part of the holotype specimen and two referred specimens. We show that the elements described as D. steini ‘furculae’ are not theropod dinosaur furculae, but rather trionychid turtle entoplastra. Given that the holotype 'furcula' is not referable to Dromaeosauridae and that the specimen is a disarticulated individual based on skeletal remains from a multitaxic bonebed, the holotype of Dakotaraptor steini is a chimera.

scholarly journals The furculae of the dromaeosaurid dinosaur Dakotaraptor steini are trionychid turtle entoplastra

2015 ◽  
Author(s):  
Victoria M. Arbour ◽  
Lindsay E. Zanno ◽  
Derek W. Larson ◽  
David C. Evans ◽  
Hans-Dieter Sues
Keyword(s):  
South Dakota ◽  
Upper Cretaceous ◽  
Skeletal Remains ◽  
Theropod Dinosaur ◽  
Hell Creek Formation ◽  
Holotype Specimen

Dakotaraptor steini is a recently described dromaeosaurid dinosaur from the Upper Cretaceous (Maastrichtian) Hell Creek Formation of South Dakota. Included within the D. steini hypodigm are three elements originally identified as furculae: one which is part of the holotype specimen and two referred specimens. We show that the elements described as D. steini ‘furculae’ are not theropod dinosaur furculae, but rather trionychid turtle entoplastra. Given that the holotype 'furcula' is not referable to Dromaeosauridae and that the specimen is a disarticulated individual based on skeletal remains from a multitaxic bonebed, the holotype of Dakotaraptor steini is a chimera.

Metatarsals of a large caenagnathid cf. Anzu wyliei (Theropoda: Oviraptorosauria) from the Hell Creek Formation in South Dakota, U.S.A.

2021 ◽  
Author(s):  
Kousuke Tsujimura ◽  
Makoto Manabe ◽  
Yumiko Chiba ◽  
Takanobu Tsuihiji
Keyword(s):  
South Dakota ◽  
Present Finding ◽  
Hell Creek Formation ◽  
Anatomical Information ◽  
Present Description ◽  
Bone Beds

Isolated metatarsals III and IV of a caenagnathid theropod likely referable to Anzu wyliei are described from a locality of the Hell Creek Formation in northwestern South Dakota of the U.S.A. These bones are missing from the holotype and only partial shafts have been described for a specimen referable to this species. Accordingly, the present description adds further anatomical information on this already well-known species of Caenagnathidae. The present finding also demonstrates the significance of isolated or fragmentary specimens found in multitaxic bone beds.

scholarly journals The Hell Creek Formation, Montana: A Stratigraphic Review and Revision Based on a Sequence Stratigraphic Approach

Geosciences ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 435
Author(s):  
Denver Fowler
Keyword(s):  
South Dakota ◽  
Lake Area ◽  
Sequence Stratigraphic ◽  
Hell Creek Formation ◽  
Accommodation Space ◽  
The North ◽  
Marine Influence ◽  
Sequence Boundaries ◽  
North And South ◽  
Upper Maastrichtian

The Upper Maastrichtian fluvial Hell Creek Formation of the Fort Peck Lake area, Montana (and regional equivalents) is notable for its vertebrate fossils and for the K-Pg mass extinction at or near its upper contact. Despite intense study, internal stratigraphy of the Hell Creek Formation is still poorly constrained, hindering study. This work reviews the stratigraphy of the Hell Creek Formation, as currently understood, and proposes important revisions to the recently proposed type section, particularly concerning complexity of the Hell Creek Formation basal contact. This work also subdivides the Montanan Hell Creek Formation into four 4th order depositional sequences, superimposed over a 3rd order marine transgression. Sequence boundaries are defined by four, laterally continuous disconformities formed by pauses in the creation of accommodation space, marked by overlying amalgamated channel complexes, or less commonly, correlative interfluve paleosols. Cyclicity in Montana may be correlative with similar 4th order cyclicity and marine influence documented in North and South Dakota, Alberta, and Saskatchewan. Magnetostratigraphy and new biostratigraphic data support correlation of the upper Montanan sequence with the North Dakotan Cantapeta tongue (and overlying fines) and Canadian Scollard and Frenchman Formations.

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