Tuesday, 9 April 2019


This lovely big fella is Isotelus rex from Churchill, Manitoba, Canada. He was found along the Hudson Bay and is the largest complete trilobite ever found. Isotelus is a genus of asaphid trilobites, an extinct group of arthropods, from the middle and upper Ordovician

Discovered by a paleo dream team, including the deeply awesome, Dave Rudkin, assistant curator of paleobiology at the Royal Ontario Museum, along with Robert Elias (Project Lead), University of Manitoba, Graham Young (Project Lead), associate curator of geology at the Manitoba Museum of Man and Nature (and adjunct professor at the University of Manitoba) and Edward Dobrzanski, Manitoba Museum during a long-term field project in 1998-1999.

The specimen measures in at a whopping 28 inches in length and is 70 percent larger than the previous record holder and warranted a new species name. The image here shows one of several replicas (casts), not the actual holotype specimen which is on exhibit at the Manitoba Museum.

There is a second complete specimen (430 mm in length) of Isotelus rex in the collections of the Geological Survey of Canada (GSC 85292 - a designated paratype). As with many such projects, financial contributions make field work and research possible. A nod to the Natural Sciences and Engineering Research Council of Canada, the University of Manitoba, the Manitoba Museum Foundation nd the Royal Ontario Museum Foundation.

Kudos as well to field crew, David Wright, Curtis Moffat and Janis Klapecki. You arrived four hundred and forty-five million years too late for sunscreen and tropical weather.

In the prophetic words of Eddard Stark, "Winter is Coming." And so it did to the Canadian prairies. Thank you to everyone involved for enduring the frozen cold, wind, rains and hail of northern Manitoba. For those who haven't had the pleasure, dear Manitoba gets blasted by cold Arctic high-pressure that drops it to a frigid -47.2 Celsius. That's a sweet, sweet -52 with wind chill.

Paper: Rudkin, D.A.; Young, G.A.; Elias, R.J.; Dobrzanski, E.P. (2003). "The World's biggest Trilobite: Isotelus rex new species from the Upper Ordovician of northern Manitoba, Canada". Palaeontology. 70 (1): 99–112. doi:10.1666/0022-3360(2003)077<0099:twbtir>2.0.CO;2. ISSN 0022-3360.

Photo credit: Mike Beauregard from Nunavut, Canada. Cast of Isotelus rex. Churchill Manitoba. 2 foot long replica housed at the University of Manitoba. Original specimen is in the Manitoba Museum. The original specimen was recovered the intertidal zone of Hudson Bay.