This has been a dinosaur-centric week for me. On Sunday, the Discovery Channel premiered a new series, Dinosaur Revolution, and on Tuesday I went to the new Dinosaur Hall at the Los Angeles County Museum of Natural History (free admission on Tuesdays—woo-hoo!).
These two experiences reinforced that almost everything I learned as a kid about dinosaurs was incorrect. Some things didn’t change, such as the fact humans and dinosaurs lived millions of years apart. Well, other than birds, which are now definitively categorized as dinosaur descendants. That’s right; dinosaurs’ closest living modern-day relatives are not reptiles, but birds. Based on their skeletal structure and egg-laying strategies, paleontologists theorize that birds either evolved from dinosaurs, or at the very least shared a common ancestor. Fossil evidence has also shown that some dinosaurs had feathers.
The centerpiece of the Hall of Dinosaurs is the T. rex growth series. An 11-foot-long “baby” T. rex, a 20-foot-long juvenile, and a 30-foot-long young adult dubbed “Thomas” stand over the partial carcass of a duck-billed Edmontosaurus. Thomas is one of the most complete T. rex skeletons ever found. It is clear that just as modern animals change shape and proportions as they grow, so too did dinosaurs.
The long reign of the dinosaurs is vividly demonstrated by the fact that Stegosaurus (Jurassic period, 150 million years ago) was further removed from T. rex than T. rex (Cretaceous period, 67 million years ago) is from humans.
Not everything in the Hall of Dinosaurs was a dinosaur. The marine reptile called Morenosaurus roamed the warm sea that once covered California during the age of dinosaurs. Their closest living relatives are snakes and monitor lizards. A pregnant Plesiosaur specimen provides the first evidence of live birth in another kind of prehistoric marine reptile. This was shown in a segment of Dinosaur Revolution.
Flying reptiles known as Pterosaurs also coexisted with dinosaurs. They were on display at the museum and were vividly animated in Dinosaur Revolution. New evidence shows them using their folded wings to help walk.
The well-arranged displays enable visitors to discover for themselves how the dinosaurs and other prehistoric animals lived. Dinosaur tracks, skin samples, pieces of internal organs, and various kinds of dinosaur eggs show that dinosaurs were diverse animals that often defy generalization. Dinosaurs and the other animals of the time were as alien as anything on Star Trek.
There is still a lot of debate about how the dinosaurs became extinct. It’s true that a giant asteroid collided with Earth 65 million years ago, but the dinosaurs weren’t all killed instantaneously. The asteroid may have triggered tsunamis, acid rain, and long-lasting dust clouds that caused global climate change. Naturally occurring earthquakes and volcanoes from shifting continents could also have caused climate and sea level changes that worked to eliminate the dinosaurs either alone or in conjunction with the asteroid effects.
One of the things that neither the Hall of Dinosaurs nor Dinosaur Revolution talked much about was whether dinosaurs were cold- or warm-blooded, or perhaps a combination of some sort. There is apparently much contention about this within the paleontological world.
If you’re in the Los Angeles area, I highly recommend going to see the new Hall of Dinosaurs. The day I was there, there were tons of school children eagerly absorbing this fascinating world. The Dinosaur Revolution miniseries is a must-see. It is the most up to date information about the reign of the dinosaurs, done in high-definition animation, and told in an exciting narrative style.