Wednesday, 30 March 2005
Paleo People By Matthew Claxton.
Heidi Henderson is a time traveller.
The Vancouver resident is part of a small group of people who have learned to see hundreds of millions of years back into the past, and to discover the extinct creatures that once walked, swam and flew in British Columbia. Her tools are few and simple. She needs good eyes, a sturdy pair of boots, a few hammers and chisels, and patience. Henderson is an amateur paleontologist, a student of the science of extinct animals and plants. The thirtysomething pharmaceutical company employee is also the head of the Vancouver Paleontological Society, which formed in the early 1990s.
Although membership has remained small, with about 80 members in the Lower Mainland, the group meets regularly for lectures at the Vancouver Museum to hear speakers on subjects such as fossil preparation and the evolution of mammoths. But a small group within the society are dedicated fossil hunters. Almost all amateurs, they head out on weekends and vacations, travelling anywhere from just a few miles from their home to halfway across the province in search of fossil finds. Their goal is simple: to unearth B.C.'s ancient past one painstaking piece at a time.
For them, every stretch of rock tells a story. "It makes the entire world more interesting," says Henderson. "The thing that's exciting about paleontology is just solving a mystery." Henderson, like most fossil hunters, doesn't seem to have an "off" button when it comes to collecting. Almost every shelf in the living room of her Kerrisdale home is lined with fossils, or with paleontology and geology publications.
The fossils on display are merely her best finds, the ones she has already spent long hours chipping free from the stone in which they were found. Elsewhere, she has large Rubbermaid containers full of rocks. Even more are stored at her parents' home. She estimates she has collected tens of thousands of specimens. Her favourite find is a large extinct clamshell she dug out from under a boulder the size of a car.
When Henderson chipped away the stone, the clam still had the mother-of-pearl intact inside. Hefting a stone larger than a softball that she found in the Queen Charlotte Islands, Henderson points out a series of regular ridges barely visible on one side of the rock. The ridges indicate the stone contains the fossil of an ammonite, a once-common animal related to the modern nautilus, squid and octopus. Ammonites have been extinct for 65 million years, wiped out at the same time the dinosaurs died out. The fossil Henderson found started as a shell and drifted to the sea bed floor after the living animal inside died. It then became covered with silt. Over thousands of years the sea bed was compacted into stone, and the shell's natural material was slowly dissolved and replaced with minerals. Eventually, the fossil eroded out as a round stone on a B.C. beach.
Henderson's quest for fossils began with childhood curiosity. She lived near a beach when she was young and collected rocks and native trading beads. Her grandfather encouraged her collecting, giving her shells and old coins. The collecting bug never left, and eventually she became interested in fossils. She joined the VanPS shortly after it was formed, and has been the group's president on and off for several years.
Her colleagues in the group include Hilmar Krocke. He doesn't have as many specimens as Henderson, but the walls and porch of his North Vancouver home are lined with rocks and fossils. Krocke, now retired, started collecting rocks in 1992 when a rock collection he had owned as a child in Austria was unexpectedly returned to him. Before long, he had added fossils to his collecting trips. "To my way of thinking, it sort of fulfills the primal instinct within us, the hunting instinct," he says. "It's very exciting."
Fossil hunting is a chancy thing, according to Krocke. A collector can search throughout a well-known fossil field and come back with nothing. The size of a find is also random. Sometimes he has come back with a beautiful sample no larger than a quarter. "Sometimes I've brought back stuff like this," he says, spreading his arms wide to indicate the boulders he has dug up. Fossil plants form a special part of Krocke's collection. Hanging on his wall is a fossilized palm frond he painstakingly chiselled out of a road embankment on the Mount Baker Highway in Washington State. The frond was chipped away in 65 pieces, which he then glued back together. "They are extremely difficult to get out," he says.
He owns chunks of fossilized wood preserved so well that their white exteriors resemble weathered driftwood. Cut open with a rock saw, the inside of the trunks reveal bright mineral greens and yellows. In some of the wood, the preservation is so good an observer can count every ring, as if the tree had been felled yesterday. Unlike many fossil hunters, Krocke is interested in his finds more because of their aesthetic quality than their scientific value. "It's something of beauty that you can find basically laying in the dirt," he says. Neither Henderson nor Krocke is likely to find a dinosaur bone on their expeditions. Aside from a handful of teeth found on Hornby Island, no dinosaur remains have ever been found in the Vancouver area. Most fossils are sea creatures and plants.
In fact, the City of Vancouver is one of the worst locations in the region to search for fossils. Within the city limits, a few plant fossils have been found in Kitsilano, but nothing else. During the last ice age, massive glaciers scraped away much of the local rock that might have contained fossils. When the glaciers melted, they covered the Lower Mainland in layers of sand and gravel, and the Fraser River has added silt and mud on top of that. Better known fossil sites are located out of town, with the Harrison Lake area one of the best known among local collectors. One scientist searching there even found part of an ichthyosaur, an ocean-dwelling reptile shaped like a modern dolphin. The Capilano area on the North Shore is rich in fossils.
The Tyaughton region in the Interior, and the Chuckanut area in Washington State are also favourite places for locals to add to their fossil collections. Vancouver Island, especially around Sooke, has a good reputation. "If you go to the Island, you're going to find some skookum fossils," says Louise Longridge. Longridge has access to a collection that Henderson and Krocke would envy.
The doctoral student at UBC's department of Earth and Ocean Sciences is working on a thesis using the fossil ammonite collection owned by the Geological Survey of Canada. Located in the basement of the ScotiaBank Tower downtown, the collection is composed of row after row of drawers, all loaded with ammonites ranging in size from a child's fingernail to one chunk of a shell that would have been three feet across, if it were complete. The GSC also owns the fibreglass cast of the largest ammonite ever found in the province. More than two metres across, the ammonite would have been a floating tank when it was alive. "It's a little like Christmas all the time," Longridge says of her work. She was drawn into paleontology from biology.
To finish her bachelor degree, she needed a directed study course, and almost at random chose one based on ammonites. She quickly fell in love with the spiral-shelled creatures and paleontology in general. Before long she had joined VanPS. "We're a little bit biased toward our ammonites," she says. Longridge is studying the evolution of ammonites for her doctoral thesis. The creatures almost went extinct about 210 million years ago, at the same time as many other land and sea animals. After the near-extinction, ammonites branched out and evolved into many new species. Longridge is studying 14 general and many more species and hopes her research will add to scientific understanding of evolution and species diversity. Most people walking through B.C. parks or driving around the province pass by fossils without knowing it.
They simply don't know what to look for. Every fossil discovery, whether in a private or government collection, begins as a shape weathering out of a rock. "Developing a search image is really important," Henderson says. "If you know what it is, you're much more likely to see it." Once a fossil is spotted, it must be removed to preserve it. Henderson compares fossils to summer strawberries, because they won't survive the winter. A fossil exposed by erosion is in danger of being destroyed by that same erosion. The two-meter ammonite fossil cast by the GSC and found near Fernie is now gone. After it was discovered, local residents prevented it from being removed. But erosion reduced the fossil to sand in just a few years. Removing a fossil can be difficult.
They can be found in rock almost as soft as chalk, or harder than concrete. Each specimen must be chipped or sawed free. "It's dirty, messy, time-involved," says Henderson, noting that fossil hunters tend to be driven in their work. "We're not fanatical, but you do become a little obsessed. You couldn't get people on a chain gang to work as hard as we do." Members of VanPS make three or four field trips a year, each involving a dozen or more people who work from sun up to sun down, crawling on their hands and knees over rough stone or wading through cold water to get at the best fossil sites. The long hours and hard work make for strong relationships, Longridge says. Since she joined the club, she has found out how quickly you get to know a group of people when everyone is working together in the middle of nowhere. With the collection work done, the most tedious and time consuming part of the work is still ahead because the fossils must be prepared and classified.
Many of the fossils collected around B.C. are not scientifically special or unique, and there is no reason to carefully remove every speck of the stone in which they are encased. "When you collect 700 you don't have time to prep them all perfectly," Longridge says. Hammers and chisels of various sizes remove the largest chunks of rock around a fossil. Collectors have a variety of techniques for the finer work. Longridge prefers an airscribe, which uses a stream of compressed air, to carefully chip off the last bits of stone. Cleaning up the best specimens takes five to six hours. Henderson has used her kitchen appliances to prepare some of her fossils. "These ones microwave rather well," she says, pointing out specimens on which the heat breaks off the outside layers of stone. "It's a crazy thing to do, but it's rather effective."
Krocke and many others use Dremel tools to chip the rock away rapidly. They need a steady hand. Hold the tool too close and the fossil is damaged. Some of the fossils found by VanPS amateurs are donated to museums, including the Vancouver Museum and a number of small town institutions around B.C. When a unique, scientifically valuable fossil is found, the VanPS has a strict code of conduct. "If it's scientifically important, it goes to science," Henderson says. Henderson has discovered a new species of prehistoric lobster, and other club members have also found unknown animals. If the discoverer of a new species is lucky, they will be immortalized by having the new creature named after them.
Both as a club member and a scientist, Longridge has found VanPS a good organization, with the members eager to share their discoveries. But they don't get rich from their hard work. Although there have been rare, multimillion dollar fossil finds, such as the famous Tyrannosaurus rex skeleton from Montana named Sue, most fossils only have value to scientists. But the scientists are grateful. The long hours put into fossil hunting by the amateurs of the VanPS, and similar groups operating throughout B.C., go a long way to help full-time scientists in their research, says Dr. Ted Danner, a retired geology teacher at UBC and one of the few professional paleontologists in Vancouver. "A lot of them become quite expert in certain fields," Danner says. At 81, Danner isn't spending much time in the field, but he still works classifying some of the smallest fossils, of microscopic marine animals and algae.
The research helps him learn about the climate of the province millions of years ago. With dinosaur fossils in B.C. limited to the northeastern parts of the province, there is no incentive to build a major museum or start a paleontology program at a local university. Without the backing of a university or museum, few full-time paleontologists make their homes in Vancouver. That gap has left the field wide open for enthusiastic non-professionals, Danner says.
While the mature members don't lack enthusiasm, VanPS is hoping to get more young people involved in the science. Henderson and other members often give talks and show their fossils, especially at schools. Others are hoping to make teaching paleontology a full-time job. Longridge wants to offer courses in the subject at local schools. She and her fellow fossil hunters want more people to be time travellers. "I love passing along what I know." posted on 03/30/2005
Sunday, 13 March 2005
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