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Edmontosaurus ecosystem from Hell Creek Formation in North Dakota

From: Ben Creisler

A new paper:

Vivi Vajda, Tyler R. Lyson, Antoine Bercovici, Jessamy H. Doman & Dean
A. Pearson (2013)
A snapshot into the terrestrial ecosystem of an exceptionally
well-preserved dinosaur (Hadrosauridae) from the Upper Cretaceous of
North Dakota, USA.
Cretaceous Research 46: 114–122
doi: http://dx.doi.org/10.1016/j.cretres.2013.08.010

A palynological investigation of sedimentary rocks enclosing an
exceptionally well-preserved fossil dinosaur (Hadrosauridae)
discovered in the upper part of the Hell Creek Formation in south
western North Dakota was conducted in order to document the immediate
paleoenvironment of this dinosaur. The specimen, an Edmontosaurus
annectens is remarkable in having exceptional three-dimensional
preservation of soft tissue around the skeleton, indicating rapid
burial. A well-preserved palynological assemblage dominated by fern
and bryophyte spores, with lesser gymnosperm and angiosperm pollen was
recovered. Sparse fresh-water algae and marine dinoflagellate cysts
were also recorded. The palynofacies is dominated by wood fragments,
including charcoal, with little amorphous organic matter. The presence
of some typical pollen taxa of the Wodehouseia spinata Assemblage Zone
including Striatellipollis striatellus, Tricolpites microreticulatus,
Leptopecopites pocockii as well as a diverse suite of
Aquilapollenites, is fully consistent with a Late Cretaceous (late
Maastrichtian) age. The palynoflora indicates a local vegetation
composed of a canopy of conifers dominated by Pinaceae and a minor
sub-canopy of Taxodium and cycads, as well as an understory of
hydrophilous ferns, mosses and herbaceous angiosperms, indicative of a
warm and humid climate – an environment where this specific hadrosaur
roamed over 66 million years ago.