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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. [ABSTRACT FROM AUTHOR]

The Danek Bonebed (Edmonton, Alberta, Canada) is a monodominant Edmontosaurus regalis assemblage of the upper Campanian (Upper Cretaceous) Horseshoe Canyon Formation. Bone histology of humeri and femora are used in this paper to test hypotheses about the growth dynamics and palaeobiology of Edmontosaurus. The high number of elements collected from the Danek Bonebed allow for an expansion of the multi-element histological record for hadrosaurs. Results indicate that Edmontosaurus had a growth trajectory similar to other large-bodied dinosaurs and reached the onset of somatic maturity at about 10-15 years of age; however, even the largest elements to preserve lines of arrested growth do not have external fundamental systems. This timing of the onset of somatic maturity agrees with the estimated body size of Edmontosaurus relative to other dinosaurs for which life-history data are available. Vascularity patterns support the hypothesis that edmontosaurs preserved at the Danek Bonebed were not subject to the same extreme seasonal environmental shifts as congenerics preserved at higher latitudes, further supporting overwintering behaviour in the latter. [ABSTRACT FROM AUTHOR]

A significant number of fossil remains of the hadrosaurid Edmontosaurus have been recovered from the Danek Bonebed (Horseshoe Canyon Formation, Upper Cretaceous, Alberta). Bones from theropod dinosaurs are scarce in this hadrosaur-dominated bonebed, but more than 60 tyrannosaurid theropod teeth have been found. The isolated tyrannosaurid teeth include juvenile and adult specimens, although the precise ontogenetic stage has not been determined. The use of multivariate analyses helps determine the variance of the sample and verifies the initial taxonomic affinities given to these teeth, showing their high potential as a useful tool to better discriminate tyrannosaurid teeth. It also provides an insight into the tyrannosaurid intraspecific variability in the Horseshoe Canyon Formation. [ABSTRACT FROM AUTHOR]

For fossil assemblages, quantitative size and shape studies are often complicated by diagenetic distortion. Different vertebrate elements, although subjected to similar burial stresses, exhibit deformations based upon their original shapes; this hypothesis is tested here by quantitatively comparing deformed humeri and femora from the Danek Bonebed (a monodominant Edmontosaurus regalis bonebed from the upper Campanian Horseshoe Canyon Formation in Edmonton, Alberta, Canada) with samples of undeformed humeri and femora from modern and fossil assemblages. Analyses suggest that at the Danek Bonebed a strong relationship exists between element length and circumference despite being distorted by crushing deformation. Major and minor axes of the midshaft cross section, however, were not uniformly distorted. Although their anatomical position did not change, the major axis became longer relative to the minor axis in distorted specimens. A regression based on the undeformed humeri was not able to accurately predict circumference in the Danek humeri. Further study might quantify the deformation of other bones in the Danek Bonebed and could be extended to other assemblages and genera. Caution should be taken when conducting studies in which diagenetic crushing may have altered morphological features of fossil vertebrate remains. [ABSTRACT FROM AUTHOR]

Tyrannosaurid cranial bones - including a maxilla, dentary, and pterygoid - were collected from a monodominant Edmontosaurus bonebed in the Horseshoe Canyon Formation exposed near the city of Edmonton, Alberta, Canada. The maxilla can be identified as Albertosaurus sarcophagus based on the narrow interfenestral strut and relatively deep dental pits along the length of the palatal shelf. Cranial bones are interpreted to have come from a single large individual that was incorporated into the site during, or temporally close to, the formation of the final taphocoenosis. This discovery constitutes the northernmost record of A. sarcophagus, and helps to narrow the geographic gap of latest Cretaceous tyrannosaurs between Alberta and Alaska. The geographic distribution of A. sarcophagus - eclipsed only in areal extent by Tyrannosaurus rex in North America - attests to the adaptability of this species, which endured regional changes in climate that forced extirpation of many ornithischian taxa during deposition of the Horseshoe Canyon Formation. [ABSTRACT FROM AUTHOR]

The Danek Bonebed is a monodominant Edmontosaurus bonebed preserving predominantly disarticulated material from the Upper Campanian Horseshoe Canyon Formation within the city limits of Edmonton, Alberta, Canada. To date, at least six dinosaur taxa have been identified at the site: Albertosaurus sarcophagus, Chasmosaurinae indet., Dromaeosauridae indet., Edmontosaurus regalis, Ornithomimidae indet., and Troodontidae indet. This bonebed has been used as a case study for creating a digital, searchable bonebed map using a geographic information system (GIS) platform. The original quarry maps produced on site are refined when digitized with new anatomical information gathered during preparation of collected specimens. Each specimen is labeled with the known specimen identification, quarry coordinates, and catalogue number. Creating a digital map of the bonebed allows easier interpretation of data and the ability to share maps to compare specific elements within the bonebed. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)