Patterns of survival and recovery following the Cenomanian-Turonian (Late Cretaceous) mass extinction in the Western Interior Basin, United States

2005 ◽  
pp. 277-298 ◽  
Author(s):  
Peter J. Harries ◽  
Erle G. Kauffman
Keyword(s):  
United States ◽  
Late Cretaceous ◽  
Mass Extinction ◽  
Western Interior Basin

The late Cenomanian oyster Lopha staufferi () – the oldest ribbed oyster in the Upper Cretaceous of the Western Interior of the United States

2016 ◽  
Vol 66 (4) ◽  
pp. 609-626
Author(s):  
Stephen C. Hook ◽  
William A. Cobban
Keyword(s):  
United States ◽  
New Mexico ◽  
Late Cretaceous ◽  
Upper Cretaceous ◽  
The United States ◽  
The North ◽  
West Central ◽  
Dakota Sandstone ◽  
Western Interior Basin ◽  
Interior Volume

Abstract Lopha staufferi (Bergquist, 1944) is a medium-sized, ribbed, Late Cretaceous oyster with a slightly curved axis and a zigzag commissure; it appears suddenly and conspicuously in upper Cenomanian rocks in the Western Interior Basin of the United States. At maturity, the ribs on both valves thicken into steep flanks that allow the oyster to increase interior volume without increasing its exterior footprint on the seafloor. Lopha staufferi is the first (earliest) ribbed oyster in the Late Cretaceous of the Western Interior, but has no ancestor in the basin. It disappears from the rock record as suddenly as it appeared, leaving no direct descendent in the basin. In the southern part of the basin where it is well constrained, L. staufferi is restricted stratigraphically to the upper Cenomanian Metoicoceras mosbyense Zone (= Dunveganoceras conditum Zone in the north). Lopha staufferi has an unusual paleogeographic distribution, occurring in only two, widely scattered areas in the basin. It has been found at several localities near the western shoreline of the Late Cretaceous Seaway in west-central New Mexico and adjacent Arizona, and in localities 1,900 km (1,200 mi) to the northeast near the eastern shoreline in northeastern Minnesota, but nowhere in between. In west-central New Mexico and adjacent Arizona, L. staufferi is a guide fossil to the Twowells Tongue of the Dakota Sandstone.

Description of new dyrosaurid specimens from the Late Cretaceous–Early Paleogene of New Jersey, United States, and comments on Hyposaurus systematics

2019 ◽  
Vol 32 (10) ◽  
pp. 1377-1393
Author(s):  
Rafael Gomes de Souza ◽  
Beatriz Marinho Hörmanseder ◽  
Rodrigo Giesta Figueiredo ◽  
Diogenes de Almeida Campos
Keyword(s):  
United States ◽  
New Jersey ◽  
Late Cretaceous ◽  
Early Paleogene

scholarly journals A new paleoecological look at the Dinwoody Formation (Lower Triassic, western USA): intrinsic versus extrinsic controls on ecosystem recovery after the end-Permian mass extinction

2013 ◽  
Vol 87 (5) ◽  
pp. 854-880 ◽  
Author(s):  
Richard Hofmann ◽  
Michael Hautmann ◽  
Hugo Bucher
Keyword(s):  
United States ◽  
Environmental Stress ◽  
Beta Diversity ◽  
Mass Extinction ◽  
Western United States ◽  
Ecosystem Recovery ◽  
Diversity Pattern ◽  
Marine Habitats ◽  
Low Diversity ◽  
Permian Mass Extinction

The Dinwoody Formation of the western United States represents an important archive of Early Triassic ecosystems in the immediate aftermath of the end-Permian mass extinction. We present a systematic description and a quantitative paleoecological analysis of its benthic faunas in order to reconstruct benthic associations and to explore the temporal and spatial variations of diversity, ecological structure and taxonomic composition throughout the earliest Triassic of the western United States. A total of 15 bivalve species, two gastropod species, and two brachiopod species are recognized in the study area. The paleoecological analysis shows that the oldest Dinwoody communities are characterized by low diversity, low ecological complexity and high dominance of few species. We suggest that this low diversity most likely reflects the consequences of the mass extinction in the first place and not necessarily the persistence of environmental stress. Whereas this diversity pattern persists into younger strata of the Dinwoody Formation in outer shelf environments, an increase in richness, evenness and guild diversity occurred around the Griesbachian–Dienerian boundary in more shallow marine habitats. This incipient recovery towards the end of the Griesbachian is in accordance with observations from other regions and thus probably represents an interregional signal. In contrast to increasing richness within communities (alpha-diversity), beta-diversity remained low during the Griesbachian and Dienerian in the study area. This low beta-diversity reflects a wide environmental and geographical range of taxa during the earliest Triassic, indicating that the increase of within-habitat diversity has not yet led to significant competitive exclusion. We hypothesize that the well-known prevalence of generalized taxa in post-extinction faunas is primarily an effect of reduced competition that allows species to exist through the full range of their fundamental niches, rather than being caused by unusual and uniform environmental stress.

Hadrosaurid migration: inferences based on stable isotope comparisons among Late Cretaceous dinosaur localities

Paleobiology ◽  
2009 ◽  
Vol 35 (2) ◽  
pp. 270-288 ◽  
Author(s):  
Henry C. Fricke ◽  
Raymond R. Rogers ◽  
Terry A. Gates
Keyword(s):  
Oxygen Isotope ◽  
Late Cretaceous ◽  
Tooth Enamel ◽  
Isotope Ratios ◽  
Isotopic Signatures ◽  
Oxygen Isotope Ratios ◽  
Drinking Waters ◽  
Carbon And Oxygen Isotope ◽  
Western Interior Basin ◽  
Major Alteration

Stable carbon and oxygen isotope ratios were measured for carbonate in samples of hadrosaurid tooth enamel and dentine, and gar scale ganoine and dentine from five geologically “contemporaneous“ (two-million-year resolution) and geographically distant late Campanian formations (Two Medicine, Dinosaur Park, Judith River, Kaiparowits, and Fruitland) in the Western Interior Basin. In all cases, isotopic offsets were observed between enamel and dentine from the same teeth, with dentine being characterized by higher and more variable carbon and oxygen isotope ratios. Isotopic offsets were also observed between gar ganoine and hadrosaur enamel in all sites analyzed. Both of these observations indicate that diagenetic overprinting of enamel isotope ratios did not entirely obfuscate primary signals. Decreases in carbon and oxygen isotope ratios were observed in hadrosaur enamel from east to west, and overlap in isotope ratios occurred only between two of the sampled sites (Dinosaur Park and Judith River Formations).The lack of isotopic overlap for enamel among localities could be due to diagenetic resetting of isotope ratios such that they reflect local groundwater effects rather than primary biogenic inputs. However, the large range in carbon isotope ratios, the consistent taxonomic offsets for enamel/ganoine data, and comparisons of enamel-dentine data from the same teeth all suggest that diagenesis is not the lone driver of the signal. In the absence of major alteration, the mostly likely explanation for the isotopic patterns observed is that hadrosaurids from the targeted formations were eating plants and drinking waters with distinct isotopic ratios. One implication of this reconstruction is that hadrosaurids in the Late Cretaceous of the Western Interior did not migrate to an extent that would obscure local isotopic signatures.

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.

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