Cunninghamia taylorii sp. nov., a Structurally Preserved Cupressaceous Conifer from the Upper Cretaceous (Campanian) Horseshoe Canyon Formation of Western North America

2013 ◽  
Vol 174 (3) ◽  
pp. 471-488 ◽  
Author(s):  
Rudolph Serbet ◽  
Benjamin Bomfleur ◽  
Gar W. Rothwell
PLoS ONE ◽  
2014 ◽  
Vol 9 (9) ◽  
pp. e108804 ◽  
Author(s):  
Victoria M. Arbour ◽  
Michael E. Burns ◽  
Robert M. Sullivan ◽  
Spencer G. Lucas ◽  
Amanda K. Cantrell ◽  
...  

2020 ◽  
Vol 57 (4) ◽  
pp. 542-552 ◽  
Author(s):  
Ramon S. Nagesan ◽  
James A. Campbell ◽  
Jason D. Pardo ◽  
Kendra I. Lennie ◽  
Matthew J. Vavrek ◽  
...  

Western North America preserves iconic dinosaur faunas from the Upper Jurassic and Upper Cretaceous, but this record is interrupted by an approximately 20 Myr gap with essentially no terrestrial vertebrate fossil localities. This poorly sampled interval is nonetheless important because it is thought to include a possible mass extinction, the origin of orogenic controls on dinosaur spatial distribution, and the origin of important Upper Cretaceous dinosaur taxa. Therefore, dinosaur-bearing rocks from this interval are of particular interest to vertebrate palaeontologists. In this study, we report on one such locality from Highwood Pass, Alberta. This locality has yielded a multitaxic assemblage, with the most diagnostic material identified so far including ankylosaurian osteoderms and a turtle plastron element. The fossil horizon lies within the upper part of the Pocaterra Creek Member of the Cadomin Formation (Blairmore Group). The fossils are assigned as Berriasian (earliest Cretaceous) in age, based on previous palynomorph analyses of the Pocaterra Creek Member and underlying and overlying strata. The fossils lie within numerous cross-bedded sandstone beds separated by pebble lenses. These sediments are indicative of a relatively high-energy depositional environment, and the distribution of these fossils over multiple beds indicates that they accumulated over multiple events, possibly flash floods. The fossils exhibit a range of surface weathering, having intact to heavily weathered cortices. The presence of definitive dinosaur material from near the Jurassic–Cretaceous boundary of Alberta establishes the oldest record of dinosaur body fossils in western Canada and provides a unique opportunity to study the Early Cretaceous dinosaur faunas of western North America.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3342 ◽  
Author(s):  
Andrew A. Farke ◽  
George E. Phillips

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.


Author(s):  
Andrew A. Farke ◽  
George E. Phillips

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.


2015 ◽  
Vol 52 (4) ◽  
pp. 250-260 ◽  
Author(s):  
Federico Fanti ◽  
Philip J. Currie ◽  
Michael E. Burns

The Grande Prairie region (Alberta, Canada) includes some of the richest Cretaceous fossil sites in North America, including the recently described bonebed of Pachyrhinosaurus lakustai at the Pipestone Creek locality. Here we describe a new multi-taxa, ceratopsian-dominated bonebed from the region, integrating taphonomic, radioisotopic, and paleoecological data. The bonebed can be traced for 107 m and has been excavated over an area of 40 m2 with an average bone density of 30–50 elements/m2. The new bonebed occurs within Unit 4 of the upper Campanian Wapiti Formation, and 40Ar/39Ar dating provides an age of 71.89 ± 0.14 Ma, thus making the site equivalent in age to the upper Drumheller Member of the lower Horseshoe Canyon Formation of central Alberta. About 88% of vertebrate remains are ceratopsian, and dromaeosaurid, hadrosaurid, troodontid, and tyrannosaurid remains have also been identified. Juvenile material, although scarce, indicates an assemblage of individuals of different ages. Specimens showed no strong preferred two-dimensional orientation but are clearly sorted vertically. Taphonomic and sedimentological interpretation support a complex pre-burial history of preserved elements as well as a depositional setting characterized by persistent waterlogged conditions as those typical of large oxbow lakes or marshy/swampy areas, as well as lacustrine settings within an alluvial plain. Being located more than 450 km inland from the paleo-coastline, the new bonebed represents one of the farthest-known inland occurrence of centrosaurines in North America, further supporting the presence of large aggregations of ceratopsian far from the coastal lowlands of the Western Interior Seaway.


2017 ◽  
Author(s):  
Andrew A. Farke ◽  
George E. Phillips

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.


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