Tuesday, 31 March 2020


A lovely fossil turtle, Desmatochelys cf. D. lowi (Williston, 1894) found by Richard Bolt in the shales of the Trent River Formation along the Puntledge River in the early 1990s. At the time, it was the first documented account of a Cretaceous marine vertebrate from the Pacific coast of Canada — a first which shows you how much we've learned about our Pacific coast in just the last few years.

Dr. Betsy Nicholls wrote up the paper and published in the Canadian Journal of Earth Sciences in 1992. She described the specimen from some post cranial elements and part of the mandible. Unfortunately, we were never able to recover the skull.

It was the Desmatchelys that inspired the 1999 BCPA Symposium conference logo held at UBC that year — a trilobite embedded within a turtle, celebrating recent significant contributions to Canadian palaeontology. It was also the inspiration for the sculpture you see here by Peter Odendag. I met Peter at the conference and was delighted to see his paleo inspired sculptures. Both his Desmatochelys and coelacanth now grace the displays at the Courtenay Museum on Vancouver Island.

While this was the first turtle find on Vancouver Island, the hunt for our fossilized reptilian friends goes back many years, but the hunt for Desmatochelys begins in the Bone Wars of the late 1800s. It was Samuel Wendell Williston who described the first specimen of Desmatochelys in the Kansas University Quarterly in 1895. Williston was a contemporary of C.H. Sternberg, Edward Drinker Cope and Othniel Charles Marsh. As history tells it, from 1877 to around 1892, both Cope and Marsh used their wealth and influence to finance their own expeditions and to procure the services and dinosaur bones from lesser fossil hunters. Williston was one of Marsh's boys.

Desmatochelys cf. D. lowi, Upper Cretaceous Haslam Formation 
In 1876, Williston wrote a letter to Marsh reporting that Sternberg had, "got one or two large turtles that are good and some pretty good saurians," (Shor, 1971:77) along the Smoky Hill River, upper Chalk Logan County.

Williston's hunt for turtles continued and it was not long after that he would hold in his hand a new species on which he would both publish and name. The specimen had been found by a railroad worker near Fairbury, Nebraska. These were hard times and fossils were exchanged for hard currency then as they are today. The specimen was passed through the hands of one curiosity seeker after another until it eventually made its way to M. A. Low. The good Master Low was more a man of science than currency and he generously donated to the University of Kansas in 1893.

That generosity was rewarded. Had the specimen not be accessioned into the collections at Kansas University by Low, it might well have been sold to Marsh and published under the name Marshanii. Instead, Williston was given the fossil to study. He published and in discovering it was a new species, chose the scientific name for the specimen. Williston tipped his hat to Low and called the new species Desmatochelys Iowi when published his finding on a well-preserved fossil turtle (KUVP 1200) from the Upper Cretaceous Benton Formation of Fairbury, Nebraska, later that year. The find included the skull, lower jaw and portions of the carapace, plastron, limbs and limb girdles. Williston described it as a new genus and species of marine turtle, Desmatochelys Iowi, and placed it in a new family, Desmatochelyidae. Since its first discovery at least five new specimens of D. lowi have been described from Cretaceous deposits in South Dakota, Kansas, Arizona, Canada, and Mexico.

In 1960, the carapace, limbs and limb girdles of a second specimen (CNHM PR 385) were found in Cretaceous sediment deposits with pre-Cambrian granites in a quarry on the South Dakota-western Minnesota border (Zangerl and Sloan, 1960). They pushed back on Williston's assertion that his new species belonged in the newly described family Desmatochelyidae, instead of recognizing it to be a primitive cheloniid within the family Cheloniidae — a family of large marine turtles characterized by their flat "hard-shells" with their streamlined, wide, rounded shapes and paddle-like forelimb flippers.

References for further reading:

  • Calloway, Jack; Nicholls, Elizabeth, eds. (1997). Ancient Marine Reptiles. Academic Press. p. 243. ISBN 9780080527215.
  • Raselli, I. 2018. Comparative cranial morphology of the Late Cretaceous protostegid sea turtle Desmatochelys lowii. PeerJ 6:e5964 https://doi.org/10.7717/peerj.5964