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How_do_scientists_study_dinosaurs_

To learn about ancient life, scientists study fossils. Finding these traces of ancient life takes time and experience. Paleontologists search carefully for bits of exposed bone, then typically transport the large piece of rock that contains the fossil back to the lab. Trackways provide some of the best clues about dinosaur behavior. Studying living birds and other reptiles, which are related to dinosaurs, gives insight into behavior and biology. Paleontologists also turn to experts in other fields. For example, geochemists analyze fossil bones and teeth for clues about paleoclimate, while paleobotanists examine coprolites for the physical and chemical traces of ancient plants. Together, these scientists are filling in the picture of what these giant dinosaurs ate, how fast they grew, and how long they lived.

Dinosaur_extinction

The extinction of non-avian dinosaurs except birds at the end of the Cretaceous has intrigued paleontologists for more than a century. One theory is that an asteroid impact 65 million years ago off the coast of Mexico generated massive tsunamis, with impact debris cutting off sunlight for months, stopping photosynthesis and causing freezing temperatures. Chemical reactions in the atmosphere caused acid rain and long-term global warming, all of which extinguished non-avian dinosaurs. However, at the same time, massive lava flows erupted across what is now southwest India. The eruptions probably caused many of the same effects as the asteroid impact. Although most scientists believe that the impact was the final blow for non-avian dinosaurs, both events could well have played a role.

What_is_a_dinosaur_

It's not what they ate or when they lived that distinguishes dinosaurs from other reptiles. It's the hole in their hip socket, which is associated with their upright gait.

Dinosaur_fossils

The American Museum of Natural History houses the largest and most spectacular collection of vertebrate fossils in the world. A fossil is any evidence of prehistoric life that is at least 10,000 years old. The most common fossils are bones and teeth, but footprints and skin impressions fossils as well. Fossils are excavated from ancient riverbeds and lakes, caves, volcanic ash falls, and tar pits.