Search

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.)

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.)

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 (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]

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]

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 systematic position of the small theropod dinosaur Troodon has had a confusing history and has been identified at different times as a lizard, a pachycephalosaurid, and a coelurosaurid. Troodon is now most commonly considered as a sister taxon to Dromeaosauridae, within Maniraptora. This study records the first evidence of Troodon in the Danek bonebed, an organic-rich member of the upper Campanian Horseshoe Canyon Formation. A single tooth (UALVP 55489) was recovered during the 2012 dig season, and it is exceptionally well-preserved. Its discovery prompted a reevaluation of variation within troodontid teeth in Alberta; it is compared here with 110 troodontid teeth from the Dinosaur Park, Horseshoe Canyon, and Wapiti formations. The results show that no distinctive morphotypes can be separated, in contrast to the results of other studies. This suggests that either troodontid teeth are not sufficiently different for identifying different species or that only one troodontid taxon is present in the Campanian of Alberta. [ABSTRACT FROM AUTHOR]