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Ghost Ranch, New Mexico

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260

Ghost Ranch, New Mexico

OLogy Series
place

In the 1940s, paleontologists from the American Museum of Natural History discovered rich fossil beds in the high desert of northern New Mexico. The area, called Ghost Ranch, would shed new light on how dinosaurs evolved. The 12,000 feet of rock layers preserve the entire age of dinosaurs, beginning when they first appeared on Earth. Today, paleontologists are still discovering valuable fossils in these rocky badlands.

A Fossil Treasure Trove
Ghost Ranch has been a popular site for paleon- tologists for over 130 years. Excavations at the Coelophysis quarry began in the 1940s led by the famous paleontologist Edwin Colbert. Since then, hundreds of dinosaur fossils have been unearthed-including many of the first dinosaurs on Earth. Scientists are still fascinated by this region today-and they're still finding fossils there. In fact, scientists are not sure why there are so many fossils at this one location. There are layers and layers of fossils where animals seem to have died in the same place. One theory is that flash floods of ancient times washed the drowned bodies of reptiles and dinosaurs downstream into concentrated deposits.

The rock layers at Ghost Ranch preserved fossils from the entire age of the dinosaurs. The lowest layer holds fossils from the:

Cretaceous Period (145-65 mya)

Jurassic Period (200-145 mya)

Triassic Period (250-200 mya)

Are you right?

Correct!

The deeper the layer, the older the rock. At the top are sandstone rocks from the Cretaceous Period. Below that are red and white colored Jurassic cliffs. Near the bottom are the red Triassic badlands, going back 230 million years, when dinosaurs first appeared.

When dinosaurs evolved in this region, it was much farther south than it is today. During that period in history, the region was:

A. a desert, with a hot, dry climate

B. a forest, with a tropical, humid climate

under an ocean

Are you right?

Correct!

Many streams and rivers flowed through the region, with trees and ferns growing along their banks. Nearby were giant conifers. In times of floods, these trees were uprooted, buried in deep mud and fossilized. Today, these "petrified trees" look like great Greek columns of marble.

Sterling Nesbitt, Paleontologist

Ghost Ranch seems to have been an excellent environment for animals. There were plenty of vegetation, water, and shelter.

Sterling Nesbitt, Paleontologist

We hope to piece together a picture of the creatures that lived here in the Late Triassic. The question is, how did they interact with one another? It's a big mystery, but we are finding more and more clues.

Paleontologists at Ghost Ranch are looking for larger bones and complete skeletons, since tiny bones don't provide much information.

Fact
or
Fiction
?

Fiction

Big or tiny, every bone is critical. Bones found in the Chinle Formation, a group of sedimen- tary layers formed 210-230 mya, may add important new knowledge about that time.

Paleontologists were the first people to inhabit the area around Ghost Ranch.

Fact
or
Fiction
?

Fiction

In fact, the area has a long and turbulent history, including the Anasazi Indians, Spanish conquistadors, and cattle rustlers.

Ghost Ranch, New Mexico
Description: Site of rich fossil beds, particularly from the Triassic Period (220 mya), when dinosaurs first began to appear on Earth
Significance: The most dinosaur fossils of any other site in North America; richest collection of early dinosaur fossils from the Triassic Period.
Exploration: First explored in the 1880s
Number of quarries: Four (Each quarry, for a different layer, has abundant dinosaur material.)

Image credits: courtesy of Giant Screen Films; Sterling Nesbitt: courtesy of AMNH; Sterling Nesbitt: courtesy of AMNH.