Adapted from Dinosaurs: The Very Latest Information
and Hands-On Activities From the Museum of the Rockies,
by Liza Charlesworth and Bonnie Sachatello-Sawyer.
A Scholastic Professional Book.
The last dinosaurs died approximately 65 million years
ago. Although the cause of their extinction is still
a mystery, climatic change, diseases, changing plant
communities, and geologic events could all have played
a role.
Lately, dinosaur extinction theories have been the subject
of much debate and controversy. A recent explanation,
supported by many scientists, suggests that dinosaurs
died out soon after a huge meteorite crashed to Earth
near the Gulf of Mexico. A giant meteorite, they reason,
could have landed with an impact that kicked up enough
dust and debris to block out sunlight for a long time — leading to a deadly chain of events. Without the
sun, all the plants died; without the plants, all the
plant-eaters died; and without the plant-eaters, all
the meat-eaters died. Sounds reasonable. But there
is one problem with this theory: Paleontologists have
not yet been able to find dinosaur skeletons in rocks
dating to the period of impact. Some evidence even
seems to indicate that all the dinosaurs had died before
the meteorite hit.
What is the answer? As paleontologists search for clues
to support their theories, they agree to disagree.