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Evolution in the Pacific Northwest

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Notable Fossil Finds:

  • In 1928, bones from 144 different animals were discovered in bluffs above Idaho's Snake River. Among 44 creatures never before identified was a 3-million-year-old zebra-like species, now called the Hagerman Horse.

  • In 1990, the skull of a four-legged plant-eating armor-plated ankylosaur was found in Alaska's Western Talkeetna Mountains. When it lived about 70 million years ago, the dinosaur was 6 feet tall, 23 feet long, and weighed 4 tons.

  • In 1996, the skull and bones of a 9,200-year-old man were found in Kennewick, Wash. Scientists suggest "Kennewick Man" died between the ages of 45 and 55 of an abscessed tooth, though a stone point had also wounded him at some time in his life.

  • In 1997, a single molar was discovered in central Oregon's John Day Fossil Beds National Monument. This tooth came from a primate that lived about 24 million years ago, making it the youngest known primate fossil in North America.

  • In 1979, "Blue Babe," a 35,000-year-old long-horned bison, was found near Fairbanks, Alaska. Its hooves, hide, and flesh were well-preserved, and its skin was blue from a mineral in the soil.

  • In 1975, 14 dinosaur footprints at least 140 million years old were found in the Black Lake area on the Alaska Peninsula. The trackway is the oldest-known dinosaur evidence in Alaska.

  • In the mid-1980s, the first dinosaur bones on Alaska's North Slope were discovered. They belonged to the duck-billed Edmontosaurus, a 10-foot-tall, 40-foot-long plant-eater.

  • The oldest domestic dog remains were found in Jaguar Cave, a Stone Age Indian site in Idaho. Two dogs were discovered, which lived about 8,300 years ago.

  • In 1935, small bones and a tooth were found inside a cavity in a rock wall in Washington's Blue Lake Basin. These probably came from an ancient two-horned rhinoceros.

  • In 1970, a mastodon was discovered in a peat bog on Washington's Olympic Peninsula. The animal had a spear wound visible on one of its ribs, though it probably wasn't fatal.

Endangered Species:

Photo of Sockeye salmon The following animal and plant species are among those listed in the federal government's register of endangered species in this region.

 Sockeye salmon

Sockeye salmon (fish)

  • Appearance: Metallic green-blue on the back and head, iridescent silver on the sides, and white or silvery on the belly. Sockeyes lack the large, black spots of many other salmon species.
  • Habitat: Feed on small floating animals, called zooplankton, in ocean waters and spawn in freshwater systems
  • Threat: Fished heavily for canning through the early 1900s; today, they are caught by nets, purse seines, and trolling gear
  • Fast fact: When spawning, males develop large teeth and hooked jaws, and both sexes turn brilliant or dark red on the back and sides.

Woodland caribou (land mammal)

  • Appearance: Its heavy coat is typically brown or olive with whitish underside and legs; males are much larger than females, and both have antlers (four to seven feet long)
  • Habitat: Largest populations inhabit higher latitudes, including Alaska's arctic tundra and feed on leafy vegetation, lichens, and twigs. Herds migrate south as far as 600 miles for winter.
  • Threat: Human hunting, oil and mineral exploration
  • Fast fact: Caribou are thought to have poor eyesight and locate food items using a keen sense of smell.

Short-tailed albatross (bird)

  • Appearance: Immature birds are dark brown, while adults have a white body, neck, and head; a dark brown tail tip; and dark wings (seven-foot wingspan)
  • Habitat: Flies over the open Pacific seas, where it feeds on fish, squid, and shrimp, and comes on land only to nest
  • Threat: Humans hunted this bird to the brink of extinction for its snowy-white breast feathers
  • Fast fact: While their range extends to the western U.S. coast, this species' only known nesting site is on the grassy slopes of an island south of Tokyo, Japan.

Bradshaw's lomatium (plant)

  • Appearance: Small, yellow-flowered plant
  • Habitat: Seasonally wet prairie lands
  • Threat: Habitat loss to urbanization and agriculture
  • Fast fact: Land-management groups are conducting prescribed burns to revitalize the native prairie plants, including the lomatium.

Columbian white-tailed deer (land mammal)

  • Appearance: Reddish-brown in summer and gray in winter, with white rings around the eyes and just behind the nose, the deer's tail is long, triangular, and fringed in white (100-150 pounds)
  • Habitat: Bottomlands and prairie woodlands
  • Threat: Hunting, loss of habitat to development and agriculture, and competing species such as elk
  • Fast fact: Heavy floods in 1996 cut populations in half, preventing its possible delisting. The species had nearly reached recovery expectations before then.

Steelhead trout (fish)

  • Appearance: This blunt-headed trout has dark spots on its back and dorsal fin, a square-shaped tail, and a reddish stripe along its sides (8-10 pounds, up to 40; up to 3.5 feet)
  • Habitat: Spawn in fast-moving streams and medium-to-large tributaries in the Upper Columbia River basin
  • Threat: Logging and development along stream beds, water diversion for agriculture, and damming; sportfishing
  • Fast fact: Unlike their cousins, the Pacific salmon species, steelheads do not die shortly after spawning.


Unlike what is now eastern North America, which emerged from the ocean more than 500 million years ago, the west remained completely submerged until the Rocky Mountains began forming about 300 million years ago. Even then, however, most of the region was covered by shallow seas. This helps explain why the Pacific Northwest's early fossil record mainly features seagoing animals and very few land animals, including dinosaurs.

The Pacific Northwest was a much drier place after the dinosaurs perished. On and off from about 25-5 million years ago, volcanoes in the Cascade Mountains oozed lava and spewed ash. Prodigious deposits formed the Columbian Plateau. Grasslands, which grew atop the lava, spread rapidly. The Palouse grasslands east of the Cascades were probably much like the African savanna is today, with an abundance of grazing animals and predators alike.

During the last Ice Age, which lasted from 2 million years ago until 10,000 years ago, a succession of glaciers scoured the land. Only life adapted for cooler conditions -- like woolly mammoths and bison -- survived in the northern latitudes. During warmer intervals between glacial advances, meltwaters rushed down from the mountains, cutting new river channels, depositing large boulders hundreds of miles away, and filling depressions to make lakes and ponds.

Alaska has been the passageway for migrating animals in the northern hemisphere several times in the past. Among the animals that have made the long journey between Asia and North America were lions and musk oxen, which came to the New World, and native horses, which spread into the Old World. Humans also made this journey, perhaps as early as 40,000 years ago.

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