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Four new dinosaur species identified

May 8, 2013
University of Alberta
Just when dinosaur researchers thought they had a thorough knowledge of ankylosaurs, a family of squat, armor-plated, plant-eaters, along comes a graduate student with some other ideas.

CMN 0210 is the holotype of Euoplocephalus tutus, CMN 8530 is the holotype of Anodontosaurus lambei, MOR 433 is the holotype of Oohkotokia horneri, and ROM 784 is the holotype of Dyoplosaurus acutosquameus. AMNH 5337, AMNH 5405, CMN 0210, ROM 784, ROM 1930, TMP 1979.14.74, TMP 1991.127.1, TMP 1997.132.1, and UALVP 31 are from the Dinosaur Park Formation. AMNH 5238 and UALVP 47977 are of uncertain stratigraphic position within Dinosaur Provincial Park. AMNH 5223, CMN 8530, ROM 832, and TMP 1997.59.1 are from the Horseshoe Canyon Formation. NHMUK R4947 is from an unknown stratigraphic position in Alberta. MOR 433, TMP 2001.42.9 (much of the anterior rostrum in heavily reconstructed), and USNM 11892 are from the Upper Two Medicine Formation in Montana. Scale equals 10 cm.
Credit: Victoria M. Arbour, Philip J. Currie; Photograph of ROM 832 by C. Brown, and of ROM 1930 by J. Arbour

Just when dinosaur researchers thought they had a thorough knowledge of ankylosaurs, a family of squat, armour plated, plant eaters, along comes University of Alberta graduate student, Victoria Arbour.

Arbour visited dinosaur fossil collections from Alberta to the U.K. examining skull armour and comparing those head details with other features of the fossilized ankylosaur remains. She made a breakthrough that resurrected research done more than 70 years ago.

Arbour explains that between 1900 and 1930 researchers had determined that small variations in the skull armour and the tail clubs in some ankylosaurs constituted four individual species of the dinosaurs.

"In the 1970s the earlier work was discarded and those four species were lumped into one called species Euoplocephalus," said Arbour.

"I examined many fossils and found I could group some fossils together because their skull armour corresponded with a particular shape of their tail club," said Arbour.

Finding common features in fossils that come from the same geologic time is evidence that the original researchers were right says Arbour. "There were in fact four different species represented by what scientists previously thought was only one species, Euoplocephalus."

The four species span a period of about 10 million years. Arbour's research shows three of those ankylosaurs species lived at the same time in what is now Dinosaur Provincial Park in southern Alberta.

Arbour says this opens the door to new questions.

"How did these three species shared their habitat, how did they divide food resources and manage to survive?" said Arbour.

Arbour will also look into how slight differences in skull ornamentation and tail shape between the species influenced the animals' long reign on Earth.

Arbour's research was published May 8, in the journal PLOS ONE.

Story Source:

The above post is reprinted from materials provided by University of Alberta. Note: Materials may be edited for content and length.

Journal Reference:

  1. Victoria M. Arbour, Philip J. Currie. Euoplocephalus tutus and the Diversity of Ankylosaurid Dinosaurs in the Late Cretaceous of Alberta, Canada, and Montana, USA. PLoS ONE, 2013; 8 (5): e62421 DOI: 10.1371/journal.pone.0062421

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University of Alberta. "Four new dinosaur species identified." ScienceDaily. ScienceDaily, 8 May 2013. <>.
University of Alberta. (2013, May 8). Four new dinosaur species identified. ScienceDaily. Retrieved October 4, 2015 from
University of Alberta. "Four new dinosaur species identified." ScienceDaily. (accessed October 4, 2015).

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