[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Danek Edmontosaurus Bonebed: Special Issue of Canadian Journal of Earth Sciences



Ben Creisler
bcreisler@gmail.com

An update. When I posted the papers, the entire issue was only
partially online. It now appears to be complete on the site--with more
articles about the dinosaur finds themselves.

http://www.nrcresearchpress.com/toc/cjes/51/11

Here are the additional papers:




Phil R. Bell & Nicolás E. Campione (2014)
Taphonomy of the Danek Bonebed: a monodominant Edmontosaurus
(Hadrosauridae) bonebed from the Horseshoe Canyon Formation, Alberta.
Canadian Journal of Earth Sciences, 51(11): 992-1006
doi: 10.1139/cjes-2014-0062
http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2014-0062


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.



===

.

Mackenzie Baert, Michael E. Burns & Philip J. Currie (2014)
Quantitative diagenetic analyses of Edmontosaurus regalis (Dinosauria:
Hadrosauridae) postcranial elements from the Danek Bonebed, Upper
Cretaceous Horseshoe Canyon Formation, Edmonton, Alberta, Canada:
implications for allometric studies of fossil organisms
Canadian Journal of Earth Sciences, 2014, 51(11): 1007-1016
doi: 10.1139/cjes-2014-0060
http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2014-0060

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.

==



Lauren J. Davies, Ryan C. McKellar, Karlis Muehlenbachs & Alexander P.
Wolfe (2014)
Isotopic characterization of organic matter from the Danek Bonebed
(Edmonton, Alberta, Canada) with special reference to amber.
Canadian Journal of Earth Sciences 51(11): 1017-1022
doi: 10.1139/cjes-2014-0057
http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2014-0057


During the course of excavating the Maastrichtian Danek Bonebed in the
city of Edmonton, a range of well-preserved organic materials was
recovered alongside vertebrate remains, including amber, coal, and
unpermineralized plant fragments. Herein, we report carbon and
hydrogen stable isotopic characterizations of these materials to
provide ancillary insights into genesis of the fossil deposit. These
analyses permit isotopic comparisons between the various organic
fractions at the Danek locality, as well as with other Late Cretaceous
localities in Alberta. The investigation of amber proves particularly
informative, with carbon stable isotope ratios that are regionally
consistent and furthermore conform to the larger, global-scale
isotopic trend for this material, and hydrogen results that inform
paleoclimatic conditions at the time of amber formation. When coupled
with chemotaxonomic information from amber Fourier-transform infrared
spectroscopy, the isotopic results indicate a consistent taxodioid
forest composition and relatively stable environmental conditions
across the three horizons that encapsulate the Danek bonebed

==



Evan Vanderven, Michael E. Burns & Philip J. Currie (2014)
Histologic growth dynamic study of Edmontosaurus regalis (Dinosauria:
Hadrosauridae) from a bonebed assemblage of the Upper Cretaceous
Horseshoe Canyon Formation, Edmonton, Alberta, Canada.
Canadian Journal of Earth Sciences, 2014, 51(11): 1023-1033
doi: 10.1139/cjes-2014-0064
http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2014-0064

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.

====



Philip J. Currie & Eva B. Koppelhus (2014)
Implications of finding a ceratopsian horncore in the Danek bonebed.
Canadian Journal of Earth Sciences, 2014, 51(11): 1034-1038
doi: 10.1139/cjes-2014-0065
http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2014-0065



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.

=


Angelica Torices, Gregory F. Funston, Shannon T. Kraichy & Philip J.
Currie (2014)
The first appearance of Troodon in the Upper Cretaceous site of Danek
Bonebed, and a reevaluation of troodontid quantitative tooth
morphotypes.
Canadian Journal of Earth Sciences 51(11): 1039-1044
doi: 10.1139/cjes-2014-0071
http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2014-0071



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.

==



Angelica Torices, Miriam Reiche & Philip J. Currie (2014)
Multivariate analysis of isolated tyrannosaurid teeth from the Danek
Bonebed, Horseshoe Canyon Formation, Alberta, Canada.
Canadian Journal of Earth Sciences, 2014, 51(11): 1045-1051
doi: 10.1139/cjes-2014-0072
http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2014-0072



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.

==



Phil R. Bell & Philip J. Currie (2014)
Albertosaurus (Dinosauria: Theropoda) material from an Edmontosaurus
bonebed (Horseshoe Canyon Formation) near Edmonton: clarification of
palaeogeographic distribution.
Canadian Journal of Earth Sciences, 2014, 51(11): 1052-1057
doi: 10.1139/cjes-2014-0050
http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2014-0050



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.





On Mon, Dec 15, 2014 at 2:32 PM, Ben Creisler <bcreisler@gmail.com> wrote:
> Ben Creisler
> bcreisler@gmail.com
>
> The new issue of the Canadian Journal Earth Sciences is devoted to the
> Danek Edmontosaurus Bonebed.  The intro material is free.
>
> free pdf:
>
> Michael E. Burns, Clive Coy, Victoria M. Arbour, Philip J. Currie &
> Eva B. Koppelhus (2014)
> The Danek Edmontosaurus Bonebed: new insights on the systematics,
> biogeography, and palaeoecology of Late Cretaceous dinosaur
> communities.
> Canadian Journal of Earth Sciences, 2014, 51(11): v-vii
> doi: 10.1139/cjes-2014-0217
> http://www.nrcresearchpress.com/doi/pdf/10.1139/cjes-2014-0217?src=recsys
>
> ***
>
> David A. Eberth & Phil R. Bell (2014)
> Stratigraphy of the Danek Bonebed (Upper Cretaceous Horseshoe Canyon
> Formation, central Alberta) and correlations with strata in the
> Drumheller and Grande Prairie regions.
> Canadian Journal of Earth Sciences, 2014, 51(11): 975-981
> doi:  10.1139/cjes-2014-0069
> http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2014-0069?src=recsys#.VI9gQCvF_To
>
> Although considerable work has been conducted on the stratigraphy and
> dinosaur assemblages of the Horseshoe Canyon Formation of southern
> Alberta, equivalent strata and assemblages in central Alberta remain
> poorly understood. Data from the Danek Bonebed (Edmonton, Alberta) are
> beginning to fill this gap. The bonebed occurs 4 m above the #9 Big
> Island Coal Seam. This stratigraphic position lies just below the
> middle of the Horseshoe Canyon Formation in the Edmonton region, and
> also lies below a thick, stratigraphically significant non-coaly
> interval that is expressed throughout central and southern Alberta.
> The stratigraphic position of the Danek Bonebed equates best with the
> uppermost Horsethief Member of the Horseshoe Canyon Formation in the
> Drumheller region and the upper part of Unit 4 of the Wapiti Formation
> in the Grande Prairie region. In both Drumheller and Grande Prairie,
> the correlated position of the bonebed underlies a zone of marine
> transgression (Drumheller Marine Tongue), which, in turn, includes the
> Campanian–Maastrichtian boundary. In the context of Geologic Time
> Scale 2004, we infer a late Campanian age of 71.0–71.3 Ma for the
> bonebed. The Danek’s dinosaurian assemblage is limited taxonomically,
> but compares well with the Edmontosaurus regalis – Pachyrhinosaurus
> canadensis fossil assemblage zone in the Drumheller region. We propose
> that a mega-herbivore faunal assemblage, characterized by
> Edmontosaurus and Pachyrhinosaurus, extended continuously across the
> climatically wet coastal plain of latest Campanian southern and
> central Alberta, and likely extended northwest into the North Slope of
> Alaska, where it persisted into the early Maastrichtian.
> ***
>
> Joshua H.F.L. Davies, Jörn-Frederik Wotzlaw, Alexander P. Wolfe &
> Larry M. Heaman (2014)
> Assessing the age of the Late Cretaceous Danek Bonebed with U–Pb 
> geochronology.
> Canadian Journal of Earth Sciences, 2014, 51(11): 982-986,
> doi: 10.1139/cjes-2014-0136
> http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2014-0136?src=recsys#.VI9gmivF_To
>
>
> An ash-rich volcaniclastic sandstone immediately underlying
> dinosaur-rich material from the Danek Bonebed in the Horseshoe Canyon
> Formation (HCF), Edmonton, Alberta, Canada, contains accessory zircon,
> which have been dated employing U–Pb geochronology. Both
> laser-ablation inductively coupled plasma mass spectrometry
> (LA-ICP-MS) and chemical abrasion isotope dilution thermal ionization
> mass spectrometry (ID-TIMS) U–Pb analyses have been conducted. The
> zircon age distributions are complex with U–Pb dates ranging from
> Precambrian to Cretaceous. We consider the youngest ID-TIMS 206Pb/238U
> date of 71.923 ± 0.068 Ma as the maximum deposition age of the
> ash-rich sandstone, placing the overlying Danek bonebed in the early
> Maastrichtian. This age is compatible with the paleontological
> assemblage from the Danek Bonebed and the regional stratigraphy. The
> zircon age distribution also implies that the HCF had a complex
> provenance of the detritus with some Archean and Proterozoic zircons,
> a group of Mesozoic, and a large compliment of Cretaceous grains. The
> results highlight the importance of high precision geochronology in
> constraining the age of important fossil deposits such as the Danek
> Bonebed.
> ***
>
> Katherine Bramble, Michael E. Burns & Philip J. Currie (2014)
> Enhancing bonebed mapping with GIS technology using the Danek Bonebed
> (Upper Cretaceous Horseshoe Canyon Formation, Edmonton, Alberta,
> Canada) as a case study.
> Canadian Journal of Earth Sciences, 2014, 51(11): 987-991
> doi: 10.1139/cjes-2014-0056
>
>
> 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.
>
>
>
> ==
>
> News release:
>
> http://www.nrcresearchpress.com/doi/story/10.4141/news.2014.12.14.295#.VI9hXivF_To
>
> http://phys.org/news/2014-12-edmontosaurus-regalis-danek-bonebed-featured.html