Geochronology of calcite‐filled joints, southeast Canada: Insight into Late Cretaceous deformation of eastern North America

Terra Nova ◽  
2020 ◽  
Vol 32 (6) ◽  
pp. 425-433
Author(s):  
Jennifer Spalding ◽  
David A. Schneider ◽  
Julie Brown
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Eastern North America ◽  
Insight Into

Late Santonian megaspore floras from the Gulf Coastal Plain (Georgia, USA)

2011 ◽  
Vol 85 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Richard Lupia
Keyword(s):  
New Species ◽  
North America ◽  
Late Cretaceous ◽  
Coastal Plain ◽  
Eastern North America ◽  
Gulf Coastal Plain ◽  
Two New Species ◽  
Western Interior Basin ◽  
Heterosporous Ferns

Fossil megaspore floras from the Late Cretaceous of North America have been studied extensively, but primarily from the Western Interior Basin. Two new megaspore floras are described from eastern North America along the Gulf Coastal Plain. Cumulatively, 10 genera and 16 species of megaspores are recognized from Allon, Georgia and along Upatoi Creek, Georgia (both late Santonian in age, ~84 Ma). Megaspores identified have affinities to both heterosporous lycopsids, e.g., Erlansonisporites, Minerisporites, and Paxillitriletes, and to heterosporous ferns, e.g., Ariadnaesporites, and Molaspora. Lycopsid megaspores are more diverse than fern megaspores in the Allon and the Upatoi Creek floras. Two new species—Erlansonisporites confundus n. sp. and Erlansonisporites potens n. sp.—are proposed.

Osteology and phylogeny of small-bodied hadrosauromorphs from an end-Cretaceous marine assemblage

2020 ◽  
Vol 191 (1) ◽  
pp. 180-200
Author(s):  
Chase Doran Brownstein
Keyword(s):  
New Jersey ◽  
North America ◽  
Late Cretaceous ◽  
Eastern Coast ◽  
Eastern North America ◽  
Post Mortem ◽  
Western North America ◽  
Dominant Group ◽  
Dinosaur Extinction ◽  
Depositional Setting

Abstract The timing of non-avian dinosaur decline is one of the most debated subjects in dinosaur palaeontology. Dinosaur faunas from the last few million years of the Mesozoic appear far less diverse than those from earlier in the Cretaceous, a trend that could suggest non-avian dinosaur extinction occurred gradually. However, the limited nature of the latest Cretaceous dinosaur record outside western North America has obscured patterns in dinosaur diversity just before the extinction. Here, I describe two associated skeletons and several isolated fossils recovered from the New Egypt Formation of New Jersey, a latest Maastrichtian unit that underlies the K–Pg boundary. The larger skeleton appears to be a small-bodied adult from a lineage outside Hadrosauridae, the dominant group of these animals during the Maastrichtian, that persisted along the eastern coast of North America. Smaller specimens are identifiable as juvenile hadrosauromorphs. These results substantiate an important assemblage of herbivorous dinosaurs from the poorly-known Cretaceous of eastern North America. The marine depositional setting for these skeletons demonstrates that proposed ecosystem preferences among hadrosauromorphs may be biased by post-mortem transportation, and the adult skeleton has implications for assessing the proposed relictual nature of Late Cretaceous eastern North American vertebrates.

scholarly journals The first reported ceratopsid dinosaur from eastern North America (Owl Creek Formation, Upper Cretaceous, Mississippi, USA)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3342 ◽  
Author(s):  
Andrew A. Farke ◽  
George E. Phillips
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Depositional Environment ◽  
Upper Cretaceous ◽  
Eastern North America ◽  
Western North America ◽  
Western Interior Seaway ◽  
Double Root ◽  
Union County ◽  
Dentary Tooth

Ceratopsids (“horned dinosaurs”) are known from western North America and Asia, a distribution reflecting an inferred subaerial link between the two landmasses during the Late Cretaceous. However, this clade was previously unknown from eastern North America, presumably due to limited outcrop of the appropriate age and depositional environment as well as the separation of eastern and western North America by the Western Interior Seaway during much of the Late Cretaceous. A dentary tooth from the Owl Creek Formation (late Maastrichtian) of Union County, Mississippi, represents the first reported occurrence of Ceratopsidae from eastern North America. This tooth shows a combination of features typical of Ceratopsidae, including a double root and a prominent, blade-like carina. Based on the age of the fossil, we hypothesize that it is consistent with a dispersal of ceratopsids into eastern North America during the very latest Cretaceous, presumably after the two halves of North America were reunited following the retreat of the Western Interior Seaway.

scholarly journals The first reported ceratopsid dinosaur from eastern North America (Owl Creek Formation, Upper Cretaceous, Mississippi, USA)

2017 ◽  
Author(s):  
Andrew A. Farke ◽  
George E. Phillips
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Depositional Environment ◽  
Upper Cretaceous ◽  
Eastern North America ◽  
Western North America ◽  
Western Interior Seaway ◽  
Double Root ◽  
Union County ◽  
Dentary Tooth

Ceratopsids (“horned dinosaurs”) are known from western North America and Asia, a distribution reflecting an inferred subaerial link between the two landmasses during the Late Cretaceous. However, this clade was previously unknown from eastern North America, presumably due to limited outcrop of the appropriate age and depositional environment as well as the separation of eastern and western North America by the Western Interior Seaway during much of the Late Cretaceous. A dentary tooth from the Owl Creek Formation (late Maastrichtian) of Union County, Mississippi, represents the first reported occurrence of Ceratopsidae from eastern North America. This tooth shows a combination of features typical of Ceratopsidae, including a double root and a prominent, blade-like carina. Based on the age of the fossil, we hypothesize that it is consistent with a dispersal of ceratopsids into eastern North America during the very latest Cretaceous, presumably after the two halves of North America were reunited following the retreat of the Western Interior Seaway.

scholarly journals The first reported ceratopsid dinosaur from eastern North America (Owl Creek Formation, Late Cretaceous, Mississippi, USA)

2017 ◽  
Author(s):  
Andrew A. Farke ◽  
George E. Phillips
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Depositional Environment ◽  
Eastern North America ◽  
Western North America ◽  
Western Interior Seaway ◽  
Double Root ◽  
Union County ◽  
Dentary Tooth

Ceratopsids (“horned dinosaurs”) are known from numerous specimens in western North America and Asia, a distribution reflecting the inferred subaerial link between the two landmasses during the Late Cretaceous. However, this clade was previously unknown from eastern North America, presumably due to limited outcrop of the appropriate age and depositional environment as well as the separation of eastern and western North America by the Western Interior Seaway during much of the Late Cretaceous. A dentary tooth from the Owl Creek Formation (late Maastrichtian) of Union County, Mississippi, represents the first reported occurrence of Ceratopsidae from eastern North America. This tooth shows a combination of features typical of Ceratopsidae, including a double root and a prominent, blade-like carina. Based on the age of the fossil, we hypothesize that it is consistent with a dispersal of ceratopsids into eastern North America during the very latest Cretaceous, after the two halves of North America were reunited following the retreat of the Western Interior Seaway.

FAUNAL RELATIONSHIPS BETWEEN EASTERN NORTH AMERICA AND EUROPE AS SHOWN BY INSECTS

1988 ◽  
Vol 120 (S144) ◽  
pp. 39-53 ◽  
Author(s):  
Gerald R. Noonan
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
North Atlantic ◽  
North American ◽  
Eastern North America ◽  
Western North America ◽  
The North ◽  
The North Atlantic ◽  
Fossil Data ◽  
Suitable Land

AbstractThe supercontinent of Pangaea, which once included most lands, fragmented during the Mesozoic. By the Late Cretaceous there were two northern land masses that were strikingly different from those of present day: Asiamerica consisting of present western North America and Asia; and Euramerica comprising Europe and eastern North America. Mild climates facilitated the spread of terrestrial organisms within each of these land masses, but epicontinental seas hindered movements between Europe and Asia and between eastern and western North America.The insects of Euramerica presumably once formed a fauna extending from eastern North America to Europe that differed from the fauna of Asiamerica. The opening of the North Atlantic separated insects in Europe from those in eastern North America. This produced vicarious patterns, with some insects of eastern North America now being more closely related phylogenetically to those of Europe than to those of western North America. Most groups of insects have not been examined for such trans-Atlantic vicariances, but studies reviewed in this paper suggest such relationships for some groups of Collembola, Hemiptera, Homoptera, Coleoptera, Diptera, and Hymenoptera.The last suitable land connections between Europe and eastern North America were severed approximately 20–35 million years ago. The insects separated by this severance evolved at different rates. Some groups split in this way have apparently undergone little evolution and have the same species on both sides of the North Atlantic, but other vicarious groups have differentiated into taxa that are now distinct at specific and supra-specific levels.The opening of the North Atlantic probably split both tropical- and temperate-adapted insects in Euramerica. However, without fossil data it is difficult to identify the biogeographical patterns resulting from such splitting of the tropical-adapted groups. Most presently recognized European and eastern North American vicarious patterns of insects were probably caused by division of Euramerica rather than dispersal across Beringia.

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