scholarly journals Detailed outcrop measured sections of the Horseshoe Canyon Formation, Red Deer and Rosebud rivers, Drumheller area, southern Alberta

1999 ◽  
Author(s):  
A P Hamblin
2020 ◽  
Vol 57 (10) ◽  
pp. 1220-1237 ◽  
Author(s):  
David A. Eberth ◽  
Sandra L. Kamo

The non-marine Horseshoe Canyon Formation (HCFm, southern Alberta) yields taxonomically diverse, late Campanian to middle Maastrichtian dinosaur assemblages that play a central role in documenting dinosaur evolution, paleoecology, and paleobiogeography leading up to the end-Cretaceous extinction. Here, we present high-precision U–Pb CA–ID–TIMS ages and the first calibrated chronostratigraphy for the HCFm using zircon grains from (1) four HCFm bentonites distributed through 129 m of section, (2) one bentonite from the underlying Bearpaw Formation, and (3) a bentonite from the overlying Battle Formation that we dated previously. In its type area, the HCFm ranges in age from 73.1–68.0 Ma. Significant paleoenvironmental and climatic changes are recorded in the formation, including (1) a transition from a warm-and-wet deltaic setting to a cooler, seasonally wet-dry coastal plain at 71.5 Ma, (2) maximum transgression of the Drumheller Marine Tongue at 70.896 ± 0.048 Ma, and (3) transition to a warm-wet alluvial plain at 69.6 Ma. The HCFm’s three mega-herbivore dinosaur assemblage zones track these changes and are calibrated as follows: Edmontosaurus regalis – Pachyrhinosaurus canadensis zone, 73.1–71.5 Ma; Hypacrosaurus altispinus – Saurolophus osborni zone, 71.5–69.6 Ma; and Eotriceratops xerinsularis zone, 69.6–68.2 Ma. The Albertosaurus Bonebed — a monodominant assemblage of tyrannosaurids in the Tolman Member — is assessed an age of 70.1 Ma. The unusual triceratopsin, Eotriceratops xerinsularis, from the Carbon Member, is assessed an age of 68.8 Ma. This chronostratigraphy is useful for refining correlations with dinosaur-bearing upper Campanian–middle Maastrichtian units in Alberta and elsewhere in North America.


2010 ◽  
Vol 47 (9) ◽  
pp. 1197-1211 ◽  
Author(s):  
Darren H. Tanke ◽  
Philip J. Currie

After many years of taxonomic uncertainty, Albertosaurus was established as a new genus in 1905, the year Alberta became a province of Canada. Gorgosaurus is a closely related tyrannosaurid from the Judithian beds of southern Alberta that was subsequently synonymized with Albertosaurus. Although most researchers consider the genera as distinct, there has been considerable confusion over the temporal and geographic range of Albertosaurus. Albertosaurus sarcophagus is only known from 13 skulls and (or) skeletons of varying completeness, and one (possibly two) bonebeds, all from the Horseshoe Canyon Formation (Campanian–Maastrichtian) of Alberta. Many of the major Albertosaurus specimens are scientifically compromised due to poor collection techniques, incomplete locality and stratigraphic information, politics, vandalism, accidents, gunplay, and landowner issues. The background of each specimen is discussed to eliminate some of the sources of confusion and to document how much of each specimen is preserved.


2014 ◽  
Vol 51 (11) ◽  
pp. 992-1006 ◽  
Author(s):  
Phil R. Bell ◽  
Nicolás E. Campione

The Danek Bonebed (Horsethief Member, Horseshoe Canyon Formation, Late Campanian) is dominated by the remains of at least 12 Edmontosaurus regalis. Skeletal remains of a tyrannosaurid and ceratopsid are also known. The predominantly disarticulated remains were interred on a periodically inundated floodplain and, although the cause of death is unknown, a sudden, catastrophic death explains the demographic spread, faunal diversity, rare greenstick fractures, and homogeneous weathering/abrasion categories of the assemblage. The Danek Bonebed shares a similar taphonomic signature to the Liscomb Bonebed (Prince Creek Formation, Alaska), but it is unique among all other described hadrosaurid bonebeds in the unusually high proportion of bite-marked bones (∼30%), suggesting scavenging played a major role in the reworking of the assemblage. The highest frequency of bite marks is found on small, often unidentifiable (and commonly ignored) bone fragments, underscoring the role that such fragments can play in taphonomic interpretation. Finally, the recognition of E. regalis from central Alberta is an important datum linking contemporaneous occurrences in southern Alberta with slightly older records of this species from the Wapiti Formation in northwestern Alberta.


2013 ◽  
Vol 32 (2) ◽  
pp. 204-234 ◽  
Author(s):  
Paul Brinkman

A Field Museum expedition to collect Late Cretaceous dinosaurs operated for three and a half months in the summer of 1922 in the Red Deer River badlands (Oldman and Dinosaur Park formations, Belly River Group) in an area now known as Dinosaur Provincial Park in southern Alberta, Canada. Associate Curator of Vertebrate Paleontology Elmer S. Riggs led the expedition. He was ably assisted by veteran collectors George F. Sternberg and John B. Abbott. A trio of novice collectors, Anthony Dombrosky, George Bedford and C. Harold Riggs, Elmer's youngest son, rounded out the party. The expedition was a success, netting several quality specimens of duckbilled dinosaurs; one small, partial theropod skeleton; an unidentified duckbilled dinosaur skull; four turtles; other miscellaneous fossil vertebrate remains; numerous fossil plants and invertebrates; and a large fossil log. In 1956, one of these specimens—a nearly complete lambeosaurine hadrosaur reconstructed as Lambeosaurus—debuted as the less fortunate partner of Gorgosaurus in the museum's iconic ‘Dinosaurs, Predator and Prey’ exhibit in Stanley Field Hall. Both of these specimens are still on display in a permanent exhibit called ‘Evolving Planet’. Another notable specimen prepared in 1999-2000 after nearly eighty years in an unopened field jacket has been identified as a juvenile Gorgosaurus. This specimen—nicknamed ‘Elmer’—was recently touring the globe as part of the ‘Dinosaurs: Ancient Fossils, New Discoveries’ exhibit. More importantly, the expedition was an invaluable shakedown experience for the fossil hunting crew and their new equipment in the months before they left on an ambitious, multi-year fossil mammal collecting expedition to Argentina and Bolivia. An oft-repeated myth holds that Riggs viewed the Alberta expedition as a failure and departed the field the moment he obtained permission to go to South America. This paper shows that myth to be unfounded.


COMPASS ◽  
2017 ◽  
Vol 1 (1) ◽  
pp. 1-12
Author(s):  
Timothy E. Allan ◽  
Matthew Bolton

This paper discusses the application of malacological identification of macrofossils in stone tools. A macroscopically distinct toolstone utilized by prehistoric peoples, reported widely in archaeological consulting literature across central and southern Alberta (Meyer et al. 2007; de Mille 2009; Bohach 2010; Porter 2014), features fossilized root traces and occasional large fossil shells. These fossils can be identified, and correlated with temporal and geologic formations indicative of the environments within which the taxa occurred. Artifacts with fossils morphologically coherent with Hydrobia, Lioplacodes, and Viviparus spp. are identified in stone artifacts analyzed in this paper. These taxa are consistent with depositional environments of Paleocene period Paskapoo Formation sedimentary rocks, particularly, as identified at the Blindman-Red Deer River confluence and Joffre roadcut paleontological localities (Hoffman and Stockey 2011). In this paper we explore how the identification of these fossils offer clues to the procurement areas which were sought out by prehistoric toolmakers. We do not suggest that all Red Deer Mudstone is from these localities, though the fossil molluscs presented so far do not refute this conclusion, but we do suggest that identifying large fossil shells can be a critical diagnostic tool for identifying the geologic origin of artifacts.


1994 ◽  
Vol 31 (10) ◽  
pp. 1501-1509 ◽  
Author(s):  
R. Bruce Rains ◽  
James A. Burns ◽  
Robert R. Young

Ghostpine Creek near Three Hills, southern Alberta, is a tributary of the Red Deer River. It has three sets of paired alluvial terraces (T-1 to T-3) in a downstream part of the valley. The rare discovery of a largely intact skeleton of plains bison (Bison bison bison) in a T-2 point bar prompted terrace mapping, 14C dating, and interpretation of the postglacial evolution of the valley. Downvalley portions of the creek began incision into the newly drained bed of glacial Lake Drumheller probably about 13 000 BP. Localized valley deepening up to 20 m, the production of erosional benches and residual spurs, and the development of partly convex-up creek paleothalwegs occurred between about 13 000 and 7600 BP, by which time basal T-1 alluvium was beginning to accumulate. Subsequent aggradation of T-1 sediment and then degradation of about 3–4 m were followed by aggradation of T-2 alluvium. These trends had taken place by 2600 BP, when the bison died and its skeletal remains were buried in uppermost sediment of a T-2 point bar. Between 2600 BP and now, the creek incised about 5 m below the former T-2 channel position and aggraded, partly synchronously, up to 3 m of T-3–floodplain alluvium. Radiocarbon-dated alluvial terrace sequences in Alberta show generally comparable trends of rapid early creek incision followed by partially overlapping episodes of net aggradation and degradation from basin to basin. However, such episodes were not closely synchronized between basins.


2014 ◽  
Vol 51 (11) ◽  
pp. 1034-1038 ◽  
Author(s):  
Philip J. Currie ◽  
Eva B. Koppelhus

In connection with the excavation of the Danek Bonebed in 2011, a half-metre long, well preserved right ceratopsian orbital horncore was recovered. The horncore belongs to the taphonomic group of larger, heavier elements from the bonebed. So far, no other ceratopsian elements have been identified from the bonebed. Ceratopsids from the Horseshoe Canyon Formation of southern Alberta include Anchiceratops, Arrhinoceratops, Eotriceratops, and Pachyrhinosaurus. The size, proportions, and gently anterolaterally procurving morphology of the horncore indicates that it is from a chasmosaurine ceratopsid. There is weak morphological information to suggest that it may represent Anchiceratops ornatus, which is the most common chasmosaurine at this stratigraphic level. The base of the specimen has been hollowed out by a sinus system, which in conjunction with its large size indicates it is probably from a mature animal. The rarity of ceratopsian remains in this and other hadrosaur bonebeds suggests horned dinosaurs were excluded from anywhere that was occupied by herds of large numbers of Edmontosaurus.


2001 ◽  
Vol 38 (12) ◽  
pp. 1689-1704 ◽  
Author(s):  
Xiao-Chun Wu ◽  
Donald B Brinkman ◽  
Richard C Fox

Borealosuchus griffithi, sp. nov., is described on the basis of an incomplete skeleton from the basal Paleocene, southern Alberta. This new species records one of a few basal Cenozoic occurrences of Crocodylia so far known. B. griffithi is most distinctive in having a markedly laterally concavo-convex snout; a deep, elongate recess or fossa on the anteroventral surface of the jugal; and a large, nearly rectangular incisive foramen. Within Borealosuchus, B. griffithi probably takes a "more crownward" position than does B. sternbergii of the late Late Cretaceous. With additional information from the new species, the diagnosis of Borealosuchus is revised.


2005 ◽  
Vol 83 (6) ◽  
pp. 591-598 ◽  
Author(s):  
Josef Bogner ◽  
Georgia L Hoffman ◽  
Kevin R Aulenback

A fossilized aroid infructescence has been recovered from the Horseshoe Canyon Formation in southern Alberta, Canada. Its stratigraphic position places it near the end of the Campanian Stage of the Late Cretaceous Epoch, at an absolute age of approximately 72 million years before present. It is one of the few Cretaceous aroid fossils known at present, and it represents a new genus of Araceae, here named Albertarum. The infructescence is fertile to the apex, and the flowers must have been bisexual. Flowers bear remains of a long, attenuated style, surrounded by a perigone of six tepals. A fracture reveals ellipsoid seeds with a thick, ribbed testa and traces of a raphe, arranged in groups of three. The gynoecium was probably trilocular with one ovule per locule, and ovules were anatropous, probably with apical–parietal or axile placentation. Bisexual, perigoniate flowers occur in subfamilies Gymnostachydoideae, Orontioideae, Pothoideae, Monsteroideae, and Lasioideae, no genera of which have ribbed seeds, but the infructescence and stylar region of Albertarum resemble those of extant Symplocarpus (Orontioideae). The Horseshoe Canyon Formation was deposited in a delta plain setting, and like Symplocarpus, Albertarum probably grew in a wetland environment.Key words: fossil, Araceae, Symplocarpus, Albertarum, Limnobiophyllum, Mayoa.


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