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Dinosaur megaherbivore turnover in Dinosaur Park Formation (Alberta)



From: Ben Creisler
bcreisler@gmail.com

A new online paper:

Jordan C. Mallon, David C. Evans, Michael J. Ryan & Jason S. Anderson (2012)
Megaherbivorous dinosaur turnover in the Dinosaur Park Formation
(upper Campanian) of Alberta, Canada.
Palaeogeography, Palaeoclimatology, Palaeoecology (advance online publication)
http://dx.doi.org/10.1016/j.palaeo.2012.06.024
http://www.sciencedirect.com/science/article/pii/S0031018212003793?v=s5


Ongoing research into the biostratigraphy of the upper Campanian
Dinosaur Park Formation (DPF) of Alberta has demonstrated that
megaherbivorous dinosaur taxa (ankylosaurs, ceratopsids, hadrosaurids)
are not homogenously distributed throughout the unit. This has
compelled proposals of different, informal assemblage zone schemes,
and the hypothesis that faunal turnover was driven by environmental
change associated with marine transgression. The current study tests
previous zonation schemes in addition to the hypothesis of turnover
pulses in the DPF. Clustering and ordination methods are used to
demonstrate the existence of two broad assemblage zones within the
DPF, each of which lasted ~ 600 Ka: a lower zone characterized by the
presence of the ceratopsid Centrosaurus apertus and the hadrosaurids
Corythosaurus, and an upper zone characterized by the presence of the
ceratopsid Styracosaurus albertensis and the hadrosaurid
Prosaurolophus maximus. These zones can be further sub-divided based
on the distributions of rarer or shorter-lived ankylosaur, ceratopsid,
and hadrosaurid species into ~ 300 Ka sub-zones. Canonical
correspondence analysis is used to explore the association between the
turnover of the megaherbivorous dinosaurs and various
palaeoevironmental proxies. Megaherbivorous dinosaur turnover most
closely corresponds to that of fossil palynomorphs. However, none of
the palaeoenvironmental proxies explains dinosaur distribution better
than a simple time gradient, suggesting that dinosaur turnover was not
inextricably linked to environmental change as predicted by the
turnover pulse hypothesis.