Sharleen’s Field Trip

Recently, Kitty Friend Sharleen’s class took a trip to the Perot Museum of Nature and Science in Dallas, TX. Sharleen was particularly interested in the dinosaurs and other fossils. Here are some highlights from her trip.

Sharleen is standing next to two dinosaur skulls. One is a carnivore (meat-eater), and one is a herbivore (plant-eater). Do you know how to tell the difference?

Look at their skulls. In the illustration below, notice that the carnivore cuts and slices food when chewing, like a pair of scissors. The herbivore clamps down on plant matter, like a pair of pliers, grinding and crushing food with a side-to-side motion.

This lumpy rock contains two fossil animals. Can you find the two sea turtles? Hint: they are upside down.

The two Toxochelys sea turtles in the exhibit were discovered by a five-year-old girl named Preston Smith in 2006, in Fannin County, Texas. The turtles lived in the Late Cretaceous, around 80 million years ago.

This is a skeleton of Protostega, a giant sea turtle the size of a small car. Protostega lived in the late Cretaceous, 80-79 million years ago. This fossil was collected in Rockwall County, Texas, and it is the largest specimen known. Even in the Cretaceous, everything was bigger in Texas!

Here is Sharleen next to two fossil ammonites, sea creatures with coiled outer shells. The one that has been split open and polished came from Dallas County, Texas (dated 100-94 million years ago). The one on the right came from Montana (dated 75-70 million years ago).

This sign shows the food chain for ancient marine animals. At the top of the chain were marine reptiles called mosasaurs. Tylosaurus was a mosasaur the size of a school bus. His head was enormous, and he could crush prey easily with his huge, cone-shaped teeth. Tylosaurus fed on birds, fish, sea turtles, and even other mosasaurs. Mid-sized repiles, like sea turtles, ate small fish and ammonites.

This Columbian mammoth skeleton was put on display in the 1980s after being assembed by one hundred volunteers. Those same volunteers later formed the Dallas Paleontological Society.

Although the Columbian mammoth was a lot bigger than an elephant, its diet was similar. Mammoths could eat hundreds of pounds of grass and other plants every day.

At the Perot museum, you can watch volunteers in the Paleo Lab as they prepare fossils for display. Large monitors show closeups of the fossils as they are being cleaned. It can take months or even years to prepare fossils in the lab.

Here is a volunteer using motorized tools to separate a sauropod dinosaur’s leg bone from the stone matrix, or natural rock, that surrounds the fossil. Sauropods were enormous, long-necked herbivores.

Sharleen was surprised to discover that dinosaurs lived as far north as Alaska during the Cretaceous, around 70-69 million years ago. Pachyrhinosaurus perotorum is a dinosaur (named for the Perot family) with a very unusual nose horn made of bony knobs.

Here is Sharleen next to a model of the reconstructed Pachyrhinosaurus. These large dinosaurs, which could weigh as much as a rhinoceros, were herbivores.

Sharleen’s class also got to see a special exhibit called T. rex: the Ultimate Predator, currently on display at the museum through September 22, 2024. The exhibit was organized by the American Museum of Natural History in New York, and it contains some of the most accurate life-size models of Tyrannosaurus rex, based on updated research.

Scientists now think that T. rex was covered in feathers, especially when young. The feathers provided insulation to keep the dinosaurs warm and acted as camouflage. Here is a reconstruction of a young T. rex with feathers. The arms of a youngster were a little bit longer than those of adults.

While a baby T. rex might have been cute, the full grown, 40-foot long dinosaur was a lot scarier. One look at his teeth makes it apparent that this dinosaur was a carnivore to be feared. As a top predator, a 6 to 9 ton adult relied on his powerful bite: 7,800 pounds of force truly made him the king of beasts.

Sharleen had a wonderful time on the field trip. Later that week, Sharleen gave a report to the class about carnivores and herbivores called “Guess what’s for dinner in the past?” Her teacher, Mrs. Avery, gave her the highest grade in the class. Great job, Sharleen!