PALEOENVIRONMENTAL RECONSTRUCTION OF THE UPPER CRETACEOUS HELL CREEK FORMATION OF THE WILLISTON BASIN, MONTANA, USA: IMPLICATIONS FROM THE QUANTITATIVE ANALYSIS OF UNIONOID BIVALVE TAXONOMIC DIVERSITY AND MORPHOLOGIC DISPARITY

Palaios ◽  
2007 ◽  
Vol 22 (1) ◽  
pp. 24-34 ◽  
Author(s):  
H. SCHOLZ ◽  
J. H. HARTMAN
Keyword(s):  
Quantitative Analysis ◽  
Upper Cretaceous ◽  
Taxonomic Diversity ◽  
Williston Basin ◽  
Paleoenvironmental Reconstruction ◽  
Hell Creek Formation

Redescription of Ankylosaurus magniventris Brown 1908 (Ankylosauridae) from the Upper Cretaceous of the Western Interior of North America

2004 ◽  
Vol 41 (8) ◽  
pp. 961-986 ◽  
Author(s):  
Kenneth Carpenter
Keyword(s):  
North America ◽  
Upper Cretaceous ◽  
The Body ◽  
Body Armor ◽  
Hell Creek Formation ◽  
South Central

The armor-plated dinosaur Ankylosaurus magniventris is redescribed based on specimens from the Hell Creek Formation of northeastern Montana, USA., Lance Formation of Wyoming, USA., and from the Scollard Formation of south-central Alberta, Canada. Except for brief descriptions, most of these specimens have not been described in detail. Ankylosaurus is one of the largest known ankylosaurids, having an estimated length of up to 6.25 m (20.5 ft). It is characterized by a long, low skull having very prominent cranial “horns” that project laterally or dorsolaterally. The body armor includes a large half-ring that sat across the base of the neck and shoulders and a large, low tail club.

The promise of taphonomy as a nomothetic discipline: taphonomic bias in two dinosaur-bearing faunas in North America

2021 ◽  
pp. 1-18
Author(s):  
Connor T. Leach ◽  
Emma Hoffman ◽  
Peter Dodson
Keyword(s):  
Upper Cretaceous ◽  
Upper Jurassic ◽  
Western United States ◽  
Morrison Formation ◽  
Faunal Assemblages ◽  
Hell Creek Formation ◽  
The World ◽  
Fossil Preservation ◽  
Dinosaur Fossil ◽  
Dinosaur Park Formation

The fossil record of dinosaurs is a rich, if biased, one with nearly complete skeletons, partial skeletons, and isolated parts found in diverse, well-studied faunal assemblages around the world. Among the recognized biases are the preferential preservation of large dinosaurs and the systematic underrepresentation of small dinosaurs. Such biases have been quantitatively described in the Upper Cretaceous (Campanian) Dinosaur Park Formation of Alberta, where large, nearly complete dinosaurs were found and described early in collecting history and small, very incomplete dinosaurs were found and described later. This pattern, apparently replicated in the Maastrichtian Hell Creek Formation of Montana, is so striking that it begs the question of whether this is a nomothetic principle for the preservation of dinosaur faunas elsewhere. We tested this hypothesis by analyzing the very well-studied dinosaur fauna of the Upper Jurassic (Kimmeridgian) Morrison Formation of the western United States. The Morrison Formation fails to show any correlation between body size and completeness, order of discovery, or order of description. Both large and small dinosaurs of the Morrison include highly complete as well as highly incomplete taxa, and both large and small dinosaurs were discovered and described early in collecting history as well as more recently. The differences in preservation between the Dinosaur Park Formation and the Morrison Formation are so striking that we posit a Dinosaur Park model of dinosaur fossil preservation and a Morrison model. Future study will show whether either or both represent durable nomothetic models for dinosaur fossil preservation.

New data on pachycephalosaurid dinosaurs (Reptilia: Ornithischia) from North America

1983 ◽  
Vol 20 (3) ◽  
pp. 462-472 ◽  
Author(s):  
Peter M. Galton ◽  
Hans-Dieter Sues
Keyword(s):  
United States ◽  
North America ◽  
Upper Cretaceous ◽  
New Genus ◽  
Biological Significance ◽  
The United States ◽  
Hell Creek Formation ◽  
Unusual Condition ◽  
Judith River Formation

In this paper several new significant specimens of pachycephalosaurid dinosaurs from Upper Cretaceous strata of Canada and the United States are described and figured. The domes of an unusual pachycephalosaurid from the Judith River Formation (Campanian) of Alberta show a slightly thickened frontal with an ornamentation of bony tubercles; they are referred to a new genus. A new genus of Pachycephalosauridae is described from the Hell Creek Formation (Maestrichtian) of Montana; it has horn-like projections on the squamosal. Sutural fusion between the quadrate and squamosal of Pachycephalosaurus is reported; this is an unusual condition among the Ornithischia. The biological significance of certain cranial features is considered.

Early Campanian Multituberculates (Mammalia: Allotheria) from the Upper Milk River Formation, Alberta

1971 ◽  
Vol 8 (8) ◽  
pp. 916-938 ◽  
Author(s):  
Richard C. Fox
Keyword(s):  
Late Cretaceous ◽  
North American ◽  
Upper Cretaceous ◽  
Sampling Error ◽  
Taxonomic Diversity ◽  
New Genus And Species ◽  
The North ◽  
Evolutionary Radiation ◽  
Mammalian Teeth ◽  
Milk River Formation

Mammalian teeth collected from the early Campanian Upper Milk River Formation, southernmost Alberta, document a hitherto unknown evolutionary radiation of Late Cretaceous ptilodontoid and taeniolabidoid multituberculates. New species of the ectypodontids Mesodma and Cimexomys, the ptilodontid Cimolodon, and the cimolomyid Meniscoessus are defined, and teeth possibly pertaining to a second species of Mesodma and two species of Cimolomys are described. A new genus and species with uncertain relationships to known multituberculate families, is tentatively classified in the Taeniolabidoidea. Among North American Late Cretaceous multituberculates, at least Mesodma, Cimexomys, Cimolodon, Cimolomys, and Meniscoessus are seen to be evolutionarily conservative during early Campanian to late Maestrichtian times. The effects of sampling error on relative taxonomic diversity at horizons in the North American Upper Cretaceous are discussed.

scholarly journals Gladius-bearing coleoids from the Upper Cretaceous Lebanese Lagerstätten: diversity, morphology, and phylogenetic implications

2015 ◽  
Vol 89 (1) ◽  
pp. 148-167 ◽  
Author(s):  
Romain Jattiot ◽  
Arnaud Brayard ◽  
Emmanuel Fara ◽  
Sylvain Charbonnier
Keyword(s):  
New Species ◽  
Fossil Record ◽  
Upper Cretaceous ◽  
Soft Part ◽  
Taxonomic Diversity ◽  
Phylogenetic Implications ◽  
Cretaceous Period ◽  
First Time ◽  
One New Species

AbstractGladius-bearing coleoids are rare in the fossil record. For the Cretaceous period, these cephalopods are mainly recorded in a few Lagerstätten in Lebanon (Haqel, Hajoula, En Nammoura, and Sahel Aalma). Here, we study 16 specimens of gladius-bearing coleoids from these Upper Cretaceous Lebanese Lagerstätten to investigate their taxonomic diversity. Besides two species that were already reported (Dorateuthis syriacaandGlyphiteuthis libanotica), one new species is identified in the Cenomanian site of Hajoula:Rachiteuthis acutalin. sp., as well as another form ofGlyphiteuthisfrom En Nammoura. Several studied specimens exhibit well-preserved soft-part characters. Among them, we document for the first time two transverse rows of sessile suckers inD.syriacaand we confirm the absence of tentacles, as well as the presence of a crop in this species. This strongly supports the phylogenetic proximity ofD.syriacawith modern vampyropods rather than with modern decabrachians. In turn, the similarity in gladius morphology between this taxon and modern squids is regarded as convergent.

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