Friday, February 12, 2016

Dinosaurs of Arizona

Dinosaurs fly high at Arizona Natural History Museum

A Tyrannosaurus bataar, similar to a Tyrannosaurus rex, fossil is on display at the Arizona Museum of Natural History.
“The Age of the Dinosaurs” is the most publicized exhibition at the Arizona Natural History Museum in Mesa, Ariz. During our visit, we first enjoyed viewing outstanding fossils of the pterosaurs that filled the skies here 71 million years ago. Then, our interest was piqued even further when we saw an accompanying film about how scientists are trying to learn more about how these winged dinosaurs flew by making a realistic model of the animal. The Quetzalcoatlus, the largest flying animal known with a wingspan of 36 feet, soared through the sky as fully lifelike as the best images in a “Jurassic Park” film.

Like those of birds, the Quetzalcoatlus’ bones were hollow to reduce weight. Because of its bone structure and expenditure of energy, the dinosaur must have been warm blooded. Its skin would have been covered with light fur.

While building the model, scientists explored the way the muscles would have worked the bones and how the brain would have managed the complex moves necessary for flight. The conclusion that surprised us the most was that baby dinosaurs were able to fly as soon as they broke out of the egg. Although the researchers failed to build a flying model that didn’t crash, they learned much, which made our appreciation of the exhibition soar.

Publicity for the museum invites visitors to “See Arizona through time,” and it means just that. The time refers to a starting point about 225 million years ago in what is now known as the Mesozoic Era. Scientists divide this era into three periods — the Triassic, Jurassic and Cretaceous — and we saw representative fossil dinosaurs from each of those periods. Dinosaurs disappeared about 66 million years ago after a comet hitting the Earth made life impossible for large animals and set the stage for our mammal ancestors to evolve in their own varied life forms.

A Quetzalcoatlus fossil soars overhead at the Arizona Natural History Museum in Mesa, Ariz.Wayne Anderson

The dinosaurs here were different from what we have seen in other museums, but to us they physically looked much the same. For example, the fossil cast we saw of a Tyrannosaurus bataar was very much like the popular Tyrannosaurus rex. A smaller dinosaur from the coelurosaur group still is unnamed but is reported to be a fast-moving predator that hunted small prey and was the closest thing to a bird, maybe even having feathers.

A camarasaurus on display was representative of what we once called brontosaurus and might have weighed as much as 50 tons. It needed its weight for protection against predators such as the T. bataar, but its weight also meant it needed to eat constantly. About two dozen dinosaur skeletons are on display that get a lot of attention from children. In addition to the skeleton display, there is a dig site where children can uncover fossils.

The three-story cliff in one of the exhibits has automaton dinosaurs, which have been carefully constructed to look like the originals, from each of the three periods. They move and roar, and their roars echo throughout the museum. To add to the primitive feel of the experience, there is a thunderstorm and flash flood rushing down the wall every 21 minutes.

As we wrote in last week’s column, the dinosaurs are part of many exhibits at the museum. The collection is large and varied enough for this to be one of the most complete of its kind we have seen.