2000 Laureate, Exploration
"I was overwhelmed. It was the largest ichthyosaur I had ever seen," Elizabeth Nicholls said of her first encounter with the fossil that she later named Shonisaurus sikanniensis. Over 21 metres long, this ichthyosaur, which looks like a dolphin with a slender, elongated snout, is the biggest prehistoric marine reptile found to date. Elizabeth Nicholls, who was a palaeontologist at the Royal Tyrrell Museum in Alberta, Canada, was named a Rolex Laureate in 2000 for her project to extract the enormous fossil from the limestone bed where it had been hidden for over 220 million years.
Shonisaurus sikanniensis was discovered in 1991 in an isolated area of British Columbia, embedded in a bank of the Sikanni Chief River, in densely wooded, uneven terrain infested with mosquitoes and visited by bears. Frequently submerged by the river, the fossil was under serious threat of erosion. However, its inaccessible location prevented palaeontologists from reaching it for more than a few weeks every summer.
Elizabeth Nicholls overcame the many challenges in this logistical nightmare. It took six years to raise the necessary funds and three gruelling excursions to the original site between 1999 and 2001 to extract the huge fossil, whose skull alone weighs one-and-a-half tonnes.
"It was all worth it," she said on receiving her Rolex Award, thanks to which she was able to finance four years of painstaking laboratory work to remove the giant ichthyosaur from its limestone matrix — a vital step before serious study of the skeleton could begin.
Parting Gift to Science
Elizabeth Nicholls died from cancer at the age of 59 on 18 October 2004. Her last academic article, which appeared in the December 2004 edition of the Journal of Vertebrate Paleontology, established the scientific community’s acceptance of Shonisaurus sikanniensis as a new species of ichthyosaur and opened new avenues of research on evolution.
Study of this extraordinary specimen has already revealed that it had no teeth. In order to feed itself, the huge marine reptile resorted to suction feeding, like beaked whales, swallowing small invertebrates in the water. However, fossils of young ichthyosaurs from around 200 million years ago, discovered in Canada and Nevada, in the United States, did have teeth. "It seems that ichthyosaurs lost their teeth when they became adults," explains Makoto Manabe of the National Science Museum of Tokyo, a long-time colleague of Dr Nicholls and co-author of her last article. "It is the most ancient occurrence of this phenomenon in ichthyosaurs. This also means that they changed their diet as they grew. But we still have to understand why."
According to Dr Don Brinkman, senior curator of the Royal Tyrrell Museum, the giant ichthyosaur was "only the culmination" of Elizabeth Nicholls’ "very productive career". He added: "Elizabeth made an important contribution to the museum’s collections throughout her career. The fossil material she collected is now available for other researchers to study."
From 2006 on, the complete skull of the Shonisaurus sikanniensis will be on display at the museum: "We need to totally reorganise our exhibition room to make space for this huge fossil," says Dr Brinkman.
Love of Fossils
On 2 November 2004, the day on which a memorial ceremony was held for Dr Nicholls at the Royal Tyrrell Museum, a replica of part of the skull was put on display in the National Science Museum of Tokyo.
Passionate about fossils since her childhood, Elizabeth Nicholls raised her two daughters before turning to palaeontology full-time and earning a doctorate on marine reptiles in 1989. "We think the world belongs to us. But fossils show us that another world exists," she said. "It’s like a history book that’s missing some pages. Finding a fossil is like discovering a lost page in the history of our planet."
According to Makoto Manabe, "Elizabeth had this energetic, determined attitude. She really was a field scientist, always ready to go to the remotest places to push science forward. Now, colleagues and students must keep up with her passion."
Published in 2005