advertisement

Dung offers clues to dinosaurs' existance

T. rex, the colossal dinosaur, was one of the largest predators. Judging by fossilized skeletons, SUE, the T. rex at the Field Museum of Natural History in Chicago being the largest, scientists believe she was a hulking 12 feet tall and tipped the scales at more than 9 tons.

T. rex lived more than 66 million years ago and all that exists today are fossilized bones, skin samples, tracks and poop.

Scientists call animal poop scat, and fossilized animal scat is called a coprolite. Paleontologists who specialize in coprolites are called paleoscatologists. A few T. rex coprolites are on view at the Smithsonian Museum in Washington, D.C., and in Alberta, Canada, at the Royal Saskatchewan Museum.

"T. rex was the apex predator in North America," said William Simpson, head of geological collections, collection manager, fossil vertebrates, Gantz Family Collections Center at the Field Museum. "An apex predator would have eaten any kind of meat."

While Simpson is a mammalian paleontologist, he still thinks T. rex was pretty cool. The world's most complete T. rex dinosaur skeleton, SUE, dominates the Field Museum's Great Hall.

Without a doubt, these giants had giant poop. One fossilized specimen from Canada was over two liters in volume. How did scientists know it's T. rex's calling card? Two clues brought it back to the giant beast - it was jammed with bone fragments and other stomach contents, and it was discovered in a place that T. rex most likely roamed.

Another T. rex specimen scientists dug up was three times that size and likely fecal matter from an oversized T. rex cousin. Luckily, the giant smell isn't fossilized along with the specimen.

But that's just one piece of poop, and if you've ever seen animal droppings, it's usually piled in a clump or mound. Herbivores like rhinos leave a huge pile, as Amy Roberts, curator of mammals at Brookfield Zoo, describes it. The zoo's male rhino, Nakali, poops a healthy four times a day and his leavings each time fill a wheelbarrow.

"Herbivore poop is less compacted. Carnivore poop is smelly - herbivore is not as offensive," Roberts said.

A heap of dung left by a T. rex had to be at least as big as the supersized rhino poop at the zoo.

Discussing the museum's collections of dinosaur and dino-related fossils, Simpson said, "We have a lot of coprolites - fossil dung - although none from T. rex."

There are many coprolites in specimens from the Green River Formation, which formed in a 52-million-year-old freshwater lake in western Wyoming.

"You'd be hard-pressed to collect a fossilized fish without seeing three, four or 10 coprolites," Simpson said.

Simpson ran through the museum's catalog of coprolites, mentioning really big samples from extinct Green River crocs, a subtropical animal from 52 million years ago when the whole world was simmering in a tropical and subtropical climate without polar ice caps and high carbon dioxide levels.

"That time is called Hot House Earth, and at the end of the Eocene Era it changes to the Ice House Earth we live in today."

Field Museum dinosaur favorites that rank high on Simpson's list are "Sauropods, the huge, long-necked dinosaurs, including Apatosaurus, Brachiosaurus, and Rapetosaurus; the museum's Tyrannosauruses, including SUE, our T. rex, and an earlier, smaller Tyrannosaur, Daspletosaurus, mounted as if it just killed a duck-billed dinosaur; and a saber-toothed marsupial, Thylacosmilus, which means pouched carving knife."

Simpson is in overall charge of the research collection at the Field, which encompasses about 100,000 specimens. They have 65,000 fossil mammals in their collection and so many invertebrate fossils that they haven't been able to catalog all of them.

"If I had to guess the number, I'd say about 2 million," he said.

The career outlook is good for students interested in the many areas of paleontology, particularly in dinosaurs, Simpson said.

"When I started in paleontology, dinosaurs were academically passe. Many paleontologists thought that everything to know about dinosaurs had been discovered. Since that time, we've gone through a resurgence - the dinosaur field has exploded.

"There are now many paleontologists hard at work searching for dinosaurs, and new species are being discovered all over the world. Field Museum scientists are searching for dinosaurs in the U.S., South America, Asia and even high in the mountains of Antarctica."

Simpson just returned from field work in Utah led by Field Museum's dinosaur curator Peter Makovicky. The expedition found hundreds of Early Cretaceous dinosaur bones, including several from a dinosaur that is probably new to science.

Check it out

Cook Memorial Library in Libertyville suggests these titles on dinosaurs:

• "Dino Dung: The Scoop on Fossil Feces" by Karen Chin and Thom Holmes

• "Everything You Need to Know about Dinosaurs: And Other Prehistoric Creatures" by John Woodward

• "Fossils" by Trudi Strain Trueit

Article Comments
Guidelines: Keep it civil and on topic; no profanity, vulgarity, slurs or personal attacks. People who harass others or joke about tragedies will be blocked. If a comment violates these standards or our terms of service, click the "flag" link in the lower-right corner of the comment box. To find our more, read our FAQ.