To commemorate the 30th anniversary of the Royal Tyrrell Museum of Palaeontology and its contribution to scientific research, the Canadian Journal of Earth Sciences released a special edition in August. Included in this special volume is the paper Marine Turtles from the Late Cretaceous of Alberta, Canada, a result of collaborative research with renowned scientists including Donald Brinkman, Royal Tyrrell Museum; Michael Densmore, Harvard School of Dental Medicine; Márton Rabi, University of Tubingen, Institut für Geowissenschaften; Michael Ryan, Cleveland Museum of Natural History; and David Evans, Royal Ontario Museum and University of Toronto.
Cheloniid turtles from the Late Cretaceous of Alberta are described in this paper. Members of this group of marine turtles, that includes the living green turtle, are thought to have originated in the Western Interior Seaway that covered the interior of North America 130-70 million years ago. Although this group is well known from localities in Kansas and Alabama, only a few specimens are known from Alberta.
At least two kinds are present, one previously new and one described in this paper. The new turtle is represented by two dentaries (lower jaws), one of which was found by the Southern Alberta Dinosaur Project group. Although known only from a lower jaw, this turtle is distinctive and was described as a new genus and species. “The holotype specimen Kimurachelys slobodae was discovered by Wendy Sloboda during the Southern Alberta Dinosaur Project, which has discovered and described more than a dozen new dinosaurs and turtles from Alberta in the past decade,” said Dr. Michael Ryan, Curator of Vertebrate Paleontology, Cleveland Museum of Natural History. The generic name, Kimurachelys, honours Marilyn Kimura, who has made significant contributions to the preservation of Alberta’s fossils and the specific name slobodae honours the discoverer.
The marine turtles described in this paper provide new insights into the early evolution of cheloniid turtles. “The specimens are about 75-73 million years old, which is younger than the well-known marine turtle assemblages from Kansas, Alabama, and South Dakota. This assemblage fills in a gap in the record of marine turtles from North America,” says Dr. Donald Brinkman. There is evidence that the marine turtles from this time are distinctly more advanced than the ones from Kansas and South Dakota. Other groups, particularly mosasaurs and fishes, also show a faunal shift. This demonstrates that there was some kind of change in community structure at about this time; however, further research is needed to determine what this change was.