Shell Microstructure and Ultrastructure in Late Cretaceous Crassatellinae (Bivalvia: Crassatellidae) from Western North America

2013 ◽  
pp. 329-329
Author(s):  
George L. Kennedy
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Western North America ◽  
Shell Microstructure

NOVEL INSECT HERBIVORY FROM THE LATE CRETACEOUS OF WESTERN NORTH AMERICA

2018 ◽  
Author(s):  
S. Augusta Maccracken ◽  
◽  
Ian M. Miller ◽  
Conrad C. Labandeira
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Insect Herbivory ◽  
Western North America

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.

scholarly journals Supplemental Material: Testing local and extraregional sediment sources for the Late Cretaceous northern Nanaimo basin, British Columbia, using 40Ar/39Ar detrital K-feldspar thermochronology

2021 ◽  
Author(s):  
V. Isava ◽  
et al.
Keyword(s):  
North America ◽  
Data Collection ◽  
Pacific Northwest ◽  
Late Cretaceous ◽  
Material Testing ◽  
Western North America ◽  
Sediment Sources ◽  
The Pacific ◽  
Step Heating ◽  
Collection Methods

<div>Table S1: Descriptions of each Nanaimo Group sample. Table S2: Description of K-feldspar separation method. Table S3: <sup>40</sup>Ar/<sup>39</sup>Ar data collection methods. Table S4: Nanaimo detrital K-feldspar <sup>40</sup>Ar/<sup>39</sup>Ar data. Table S5: K-feldspar <sup>40</sup>Ar/<sup>39</sup>Ar incremental-heating data from the Pacific Northwest. Table S6: Biotite and muscovite <sup>40</sup>Ar/<sup>39</sup>Ar incremental-heating data from samples from the Pacific Northwest. Table S7: Biotite K-Ar and <sup>40</sup>Ar/<sup>39</sup>Ar age database used to construct Figures 10, 11, and 12 for selected Cretaceous batholiths of western North America, including references. Table S8: References used to construct Figures 8, 10, 11, 12, and 13. Figure S1: <sup>40</sup>Ar/<sup>39</sup>Ar step-heating plots for K-feldspar, biotite, and muscovite from basement samples from the Pacific Northwest. <br></div>

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