fossils

Manitoba’s marine monsters

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Henry
Sharpe

Guest Writer
As Canada celebrates its 150th birthday, we’re taking the summer to cover some of the most incredible fossils that Canada has contributed to paleontology. To start it off, we’re looking at the Pierre Shale of southern Manitoba, an under-appreciated location that has produced world record-holding sea monsters.

Manitoba is not particularly well known for its fossils because it does not produce any dinosaurs. Popular museums in the province of Alberta boast massive skeletons of dinosaurs like Albertosaurus and Pachyrhinosaurus. The small Canadian Fossil Discovery Centre in Morden, Manitoba, instead displays many marine fossils, which despite their scientific significance, draw far fewer visitors than a massive Tyrannosaurus. The reason for Manitoba’s aquatic bounty is because in the Late Cretaceous, Manitoba was completely underwater, so far offshore that not even the few dinosaurs that washed out to sea could float out that far.


Ancient marine reptiles are not uncommon in the rock formations of Canada. The marine sediments of Alberta and British Columbia have provided numerous fossils of plesiosaurs, ichthyosaurs, turtles, and birds, many of these incredibly large. The massive Shastasaurus sikanniensis represents the largest ichthyosaur known. The largest specimen of this species, measuring a massive 21 meters (69 feet), was excavated in the shales of British Columbia.


Mosasaurs are another group of plentiful marine reptiles found in Canada. These aquatic lizards were among the last of the marine reptiles that lived before the end-Cretaceous extinction that also killed the dinosaurs. The first mosasaurs found in Canada were actually found in Manitoba, discovered in 1934 by Charles M. Sternberg, of the legendary Sternberg fossil-hunting family. Most of these mosasaurs were small, however, barely larger than five meters (15 feet), and certainly didn’t measure up to the giants discovered in Europe and the United States.


And then, in the 1960s, reports in scientific journals began mentioning a massive specimen, known only from partial fossils, discovered in rocks from the Manitoba portion of the Pierre Shale Formation. In 1988, this monster was named as a new species of the European genus Hainosaurus, which would last until 2010, when it was moved into an American genus, now to be known as Tylosaurus pembinensis. This fossil was displayed in the Canadian Fossil Discovery Centre and nicknamed “Bruce”, and in 2014, it was placed in the Guinness Book of World Records for being the largest fossil mosasaur on public display.



The diversity of marine life in Late Cretaceous Manitoba by Henry Sharpe


Today, “Bruce” is one of the most famous mosasaurs in the world, and has been joined by numerous other fossils, though not quite as large, such as the specimens “Suzy” and “Angus.” Together, this species has been hailed as the top hunters of their domain. However, there was another predator in the seas of Cretaceous Manitoba that rivaled these marine lizards in size, one that is known only from a few fragmentary fossils.


In 1987, Betsy Nicholls and Henry Izaak announced the discovery of six massive fossils from the same area in Manitoba that “Bruce” was found. They were squid pens – hard spoon-shaped organs that serve as internal support for the animal. The largest, though incomplete, would have measured over two meters (6.5 feet) long. It belonged to an animal that would have been at least 8 meters (25 feet long) with soft tissues intact. These fossils were from a species called Tusoteuthis longa, first discovered in the chalks of Kansas from a few small specimens. Even today these fossils from Manitoba remain the largest specimens of Tusoteuthis ever discovered.



An intepretation of Tusoteuthis by Henry Sharpe


Today we know a bit more about this enigmatic animal. Sharks and large mosasaurs hunted them, and on at least one occasion a fish attempted to eat a juvenile, only to choke to death. Scientists now think that Tusoteuthis was, in fact, a close relative of the mysterious, deep-sea vampire squid, which, despite its misleading name, was not a squid at all.


However, with this comes more questions. Modern-day vampire squid eats small bits of dead organic matter that sink down to the deep depths where it lives, using a small pair of string-like feeder arms. But vampire squid is small, only 28 cm (11 inches) long. All other giant cephalopods eat large prey, and Tusoteuthis was big enough to eat a small mosasaur. Perhaps it fed like some octopuses, trapping its prey under the webs between its arms and the sea floor so it could crush them with its beak. Or maybe it had long tentacles to grab and pull prey towards the mouth. We would need an excellently preserved fossil to tell for sure.


The Cretaceous shales of Manitoba have provided giants to the world, from record-breaking mosasaurs to vampire squid that were the biggest of the big. However, not all the fossils found in this area will see the light of day. With virtually no funding, the CFDC often has to work quickly to extract Manitoba’s wealth of fossils before mining operations can take the land. To help ensure that these amazing discoveries can continue to come to light, the CFDC is always accepting volunteer help, as well as donations to help the museum continue to be a player on the world stage of paleontology.


You can learn more about the Canadian Fossil Discovery Centre at their website.

Image Credit: Henry Sharpe

Dafbaa77e8bcc9aef4c58740f1cf0cd7

Henry
Sharpe

Guest Writer


http://sulc.us/df040
http://www.eartharchives.org/articles/manitoba-s-marine-monsters/