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Alberta is a great place for a dinosaur palaeontologist, with plenty of preserved skeletons and some of the best evidence for dinosaurs in the world.

However, in the Willow Creek Formation of southwestern Alberta, which records the last few million years before the extinction of dinosaurs, only three kinds of dinosaur skeletons have been found: Tyrannosaurus rex, an undetermined hadrosaur (duck-billed dinosaur), and an undetermined leptoceratopsid (small horned dinosaur). Were those the only dinosaurs living here during that time? Unlikely, but how do we know what dinosaurs were present if their skeletons weren’t preserved?

Unlike many geological formations in Alberta, dinosaur eggshells are quite common in the Willow Creek Formation. The ancient soils (a.k.a. paleosols) present in the formation suggest that conditions were arid to semi-arid at the time, which led to excellent preservation of dinosaur eggshell. Like skeletons, eggshells tend to be distinctive between the various kinds of dinosaurs and can be used to identify what dinosaurs were present.

A new scientific article by our Curator of Dinosaur Palaeoecology, François Therrien, in collaboration with Darla K. Zelenitsky, Kohei Tanaka, Philip J. Currie, and Christopher L. DeBuhr, presents an analysis of eggshells discovered in the Willow Creek Formation. The team inspected hundreds of dinosaur eggshells recovered from several sites in southwestern Alberta. They were able to determine that the eggshell fragments were produced by at least seven different types of dinosaurs: two ornithopods (a group of bipedal, herbivorous dinosaurs, including hadrosaurs) and five small theropods, including oviraptorosaurs, troodontids, and dromaeosaurs (colloquially, raptors). Because researchers frequently cannot correlate an eggshell with a specific species unless it is associated with a parent or a baby inside the egg, eggshells are given their own species names, in parallel to the way skeletons are named. These are called ootaxa.

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Montanoolithus eggshell, belonging to a small theropod, was discovered in southwestern Alberta. Art by Julius T. Csotonyi.

This research triples the known dinosaur diversity of the Willow Creek Formation, from three species based on skeletons only, to at least nine known from skeletons and eggshells. In addition, it extends the known temporal range of some of the ootaxa to 10 million years and gives a better sense of the ancient ecosystem in southwestern Alberta at the end of the Age of the Dinosaurs.

The article, titled “Latest Cretaceous eggshell assemblage from the Willow Creek Formation (upper Maastrichtian – lower Paleocene) of Alberta, Canada, reveals higher dinosaur diversity than represented by skeletal remains,” was published in the January 2017 issue of the Canadian Journal of Earth Science.

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Palaeontological resources in Alberta are protected under the Historical Resources Act. This not only includes fossils, but also palaeontological significant sites. There are three sites designated in the province: the Willow Creek Hoodoos, Grande Cache Trackways, and Devil’s Coulee Dinosaur Egg Site (Devil’s Coulee). The Resource Management program at the Royal Tyrrell Museum of Palaeontology (RTMP) manages the protection and public use at these sites. I am going to discuss some of the changes that we have recently made at Devil’s Coulee to improve the protection and visitor experience at the site.

Devil’s Coulee is the richest dinosaur nesting site found in Canada and the third nesting site discovered in North America. The site was found in May 1987 near Warner, Alberta and was designated a Provincial Historic Resource same year due to its significance. Finds at the site include young dinosaurs, eggs, embryonic bones, and nests of hadrosaurs, as well as fossils from other types of animals from 75 million years ago. With the significant discoveries and the ongoing research producing new discoveries, the site is very sensitive in nature.

Since the mid-1990s, the RTMP has worked with the Devil’s Coulee Cooperating Society and its museum in Warner to provide tours to the site. Over the past two years, we have been working to find a balance between protection at Devil’s Coulee and quality visitor experiences. Currently, the site is only accessible through a guided tour. This will continue as a form of protection from theft and vandalism, but also as a way to provide an enhanced visitor experience. Improvements have been made to training the tour guides to increase their knowledge of fossils, geology, and dinosaurs. As many of the fossils are very small, we are also developing a dedicated path for the guides to follow, and will install a low fence in the most sensitive areas to ensure that fossils are not inadvertently destroyed during tours.

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The RTMP is updating photos on the signs and creating a relevant story line for the hike to follow. One sign will even include touch specimens of eggshell. People who visit the site can also take part in an activity to search for fossils at a microsite. We are adding a fossil box for people to identify the fossils they find to ones in the box. This provides the opportunity to see and touch real fossils. However, it is important to note that as a designated site, removal of fossils from Devil’s Coulee is illegal. Visitors are informed of this and the tour guides carefully monitor all activities to prevent theft. We hope that with the guides, signs, and activities we will accommodate a number of learning styles so that everyone enjoys their visit.

We are happy to be able to run tours out to a sensitive site such as this and provide a variety of interpretive activities, while still maintaining the integrity of the site. Implementation of the new protective and interpretive elements is still in progress, but should be ready for visitors to enjoy by May 2015. If you would like more information about tours at Devil’s Coulee you can visit the Devil’s Coulee Dinosaur Heritage Museum website: www.devilscoulee.com

– Jen Bancescu, Resource Management

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