The 21-metre-long ichthyosaur is the centrepiece of “Triassic Giant”, an exhibit that opened in June 2008 at the Royal Tyrrell Museum in Drumheller, Alberta. The 220-million-year-old skeleton was removed from the banks of the Sikanni Chief River in north-eastern British Columbia by a field crew led by the late Elizabeth Nicholls, a Rolex Awards Laureate and former curator of marine reptiles at the museum.
The exhibit will be on display until 2010.
A Canadian-American palaeontologist and a leading authority on prehistoric marine reptiles, Dr Nicholls died of cancer in 2004. The exhibit includes a tribute to her, focusing particularly on her key role in recovering the giant sea creature.
Within months of the skeleton’s discovery in 1991, Nicholls visited the isolated site to inspect the ichthyosaur, whose size astonished the scientific community. Experts had previously assumed that marine reptiles had grown no larger than 15 metres.
Despite daunting obstacles, Dr Nicholls decided to undertake the complex task of moving the skeleton to the museum for research and investigation. The densely wooded site was two kilometres from the nearest road, and much of the heavy equipment – jackhammers, compressors and rock saws – needed for the excavation had to be flown in by helicopter. Work was only possible during summer months, as the river flooded the site for much of the year. Swarms of mosquitoes plagued workers, who also had to worry about attacks from grizzly and black bears.
According to Makoto Manabe, a Japanese palaeontologist who collaborated on the project, Dr Nicholls, known to her colleagues as Betsy, brought to the task a lifelong passion for ancient creatures. “Betsy loved fossils,” says Manabe, who is curator of fossil reptiles and birds at the National Museum of Nature and Science in Tokyo. “She started collecting fossils as a child, and was always excited about finding something new. She loved fieldwork and being outside rather than sitting in an office or a laboratory.”
During three years of excavation beginning in 1999, Dr Nicholls spent months on site supervising the delicate project, including the lifting of 4,000kg fossil-bearing limestone blocks by a giant helicopter.
“Excavating such large fossils requires a lot of management skills. There was a big team of us there, and Betsy was a really good leader. She was quick to decide what to do and precise in giving instructions. She was a good team leader, and that made it possible to get the fossils out of the rocks in that remote location,” explains Dr Manabe, who co-authored with Nicholls a 2004 report in which the two scientists dubbed the find the Shonisaurus sikanniensis.
Don Brinkman, the senior curator at the Royal Tyrrell Museum and assistant director in charge of collections, preservation and research, says his late colleague had the right skill set for the task of bringing the marine reptile out of the wilderness. “She was a strong environmentalist and she could think through a question very clearly. She tended to bring people together both socially and scientifically.”
Her singular dedication to the project won Dr Nicholls widespread praise. Gilbert M. Grosvenor, chair of the board of trustees of the National Geographic Society and a member of the Rolex Awards Selection Committee that chose Dr Nicholls’ project in 2000, says that while other palaeontologists could have recognized the uniqueness of the discovery, “very few would possess the creativity, mechanical skills and determination to excavate this gigantic 220-million-year old specimen from a limestone grave.”
Funds from Dr Nicholls’ Rolex Award paid for the transport of the fossils to the museum and the subsequent laboratory work necessary to prepare them for public viewing.
“Without Rolex, we couldn’t have completed the excavation and study,” Manabe says. “We would have had to stop in the middle and left the rest of the fossils at the site.”
The exhibit features a life-size silhouette of Shonisaurus sikanniensis on the exhibit hall floor, with segments of the original specimen set atop it. A diorama along one wall presents an imaginary view of the animal swimming underwater.
Photographs of the recovery site, provided courtesy of the Rolex Awards Secretariat, help visitors understand the logistical difficulties that Dr Nicholls and her colleagues had to overcome in the wilderness.
Dr Manabe, whose own museum contains a life-size cast of the posterior section of the ichthyosaur’s head, measuring 2.4m in length and 1.8m in width, says studies of the fossil remains have raised new questions about the ancient reptile. He and Dr Nicholls travelled to Nevada to inspect a smaller species of Shonisaurus that had been found there. They found that sub-adult individuals had big teeth while adult individuals did not have the teeth at all. The remains of the Canadian Shonisaurus showed no signs of teeth.
The differences between the two, Manabe says, have led to conclusions that the larger animal might have had teeth in its early life, but then lost them as it matured. He believes the animal could have developed a baleen-like filter, similar to modern marine mammals like the blue whale (the largest animal ever to have existed), or possibly had a beak with some sort of hard material that served to pinch prey. Further studies of the recovered fossils might offer greater insight into the life of the ancient creature.
For more information about the “Triassic Giant” exhibit, visit tyrrellmuseum.comLearn more about Elizabeth Nicholls