Dinosaurs under the Aurora

2. Tracks Lead the Way: Circumarctic Discoveries from Svalbard to Koryakia

11 2 TRACKS LEAD THE WAY Circumarctic Dinosaur Discoveries from Svalbard to Koryakia Geologists . . . inhabit scenes that no one ever saw, scenes of global sweep, gone and gone again, including seas, mountains, rivers, forests , and archipelagos of aching beauty, rising in volcanic violence to settle down quietly and forever disappear—almost disappear. —John McPhee, Basin and Range The following account of the history of dinosaur discoveries in the Arctic begins in the Svalbard Archipelago in the eastern Arctic, where the first evidence of Arctic dinosaurs was found, and then proceeds to the western Arctic and sites in Canada’s Arctic Islands, the Northwest Territories, and the Yukon Territory. From here discoveries in eastern and northeastern Siberia are detailed in an attempt to set the stage and develop a proper perspective for the more extensive treatment of the discovery of dinosaurs on Alaska’s Arctic North Slope. Dinosaur fossils were first discovered in the Arctic by scientists in a most unlikely archipelago of isolated islands now known by the Norwegian name Svalbard. Originally referred to in Dutch as “Spitzbergen,” the name, which means “pointed mountains,” refers to the largest island’s extremely rugged topography. This barren and wind-swept group of islands are north of the Fenno-Scandinavian Peninsula, due west of the Russian islands of Novaya Zemlya and due east of Greenland (see plate 1). Svalbard is near the western margin of the eastern Arctic and is one of the largest pieces of land in a land-poor section of the Arctic Ocean. Svalbard has, for most of its recent history, been just a few degrees south of the great Arctic ice cap. The present global warming trend has produced a dramatic thinning of the ice and a poleward retreat of the ice cap margin over the last decade.1 Although the Svalbard Archipelago is presently more than 10° N of the Arctic Circle, it was at or below the paleo-Arctic circle during the Early Cretaceous.2 The year is 1960 and the twenty-first International Geological Congress is to be held in Norway. Prior to the meeting an international group of geologists and paleontologists have the rare opportunity, as part of an The Svalbard Archipelago Dinosaurs under the Aurora 12 Fig. 2.1. North polar dinosaur distribution map listing types of dinosaurs (avian and nonavian) and ichnofossils . Credit: Dixon Jones and David Smith (modified from Rich, Vickers-Rich, and Gangloff 2002). internationally sponsored field excursion, to look at exposures of rocks near the top of the world that span a huge chunk of geologic time. Most importantly , the rocks represent a critical time span that includes the evolution of the dinosaurs and their direct ancestors. Earlier geologic mapping and field studies on the largest island of Spitzbergen in the Svalbard Archipelago had established the presence of both marine and terrestrial rock units as well as their age. The trip is one of several that have been scheduled as part of the Tracks Lead the Way 13 Fig. 2.2. SpitzbergenSvalbard . View across Sassenfjorden toward Billefjorden . Block of Festningen sandstone in foreground. Photo credit: Patrick Drukenmiller. Dinosaurs under the Aurora 14 International Geological Congress meeting.3 As is often the case in science, serendipity plays a significant role in the discovery of new evidence. The field party came to the rugged fjord-rich southwestern part of Spitzbergen by ship in August. The excursion vessel, the Valkyrien, acted as a dormitory and base for the participants who made daily trips to explore the spectacular outcroppings of rocks along the walls of the fjords. It was near the end of one of these day trips to the Grønfjorden that two of the scientists, Albert de Lapparent and Robert Laffitte, found themselves at the top of a steep slab of sandstone that plunged onto a narrow beach below. They carefully climbed down to the base of the sandstone slab in order to study the sequence of rocks from a less precarious position. As their eyes adjusted to the low oblique light and the surface texture of the sandstone, they were astonished to see a series of thirteen large three-toed footprints incised in the rock, part of a trackway.4 The two scientists were surprised because they were supposed to be in marine rocks and because the field guides made no mention of fossil footprints. The two were quickly joined by others who heard their shouts. Not expecting to...