Iowa Alumni Magazine | June 2008 | Features

Rocks of Ages

By Tina Owen
Ancient treasures that offer clues to our world's history find a home at the University of Iowa.

Common enough to lurk in suburban gravel driveways, faraway beaches, and Iowa fields. Rare enough that only a handful of survivors emerged unscathed from some of the most tumultuous periods in Earth's history. Tiny enough to fit on the head of a pin. Gargantuan enough to tip the scales at several tons.

What is this mass of contradictions? The University of Iowa's extensive fossil collection—considered to be one of the five most significant collections held by an American university. Carefully protected in the drawers, shelves, boxes, and cupboards of the paleontology repository in Trowbridge Hall rest more than one million petrified remains of prehistoric plants, insects, fish, and all manner of creatures great and small.

Many of the finds date back to the 19th century—the era of famous and pioneering UI collectors such as Samuel Calvin and Thomas Macbride—but current scientists, researchers, and enthusiastic amateur fossil-hunters still regularly add to the enormous collection. Visitors sometimes ask collections manager Tiffany Adrain, 03MS, whether the university hasn't got enough fossils by now.

"People are always finding new species. There are still things out in the world—living or fossilized—that we don't know about yet," she replies. "Paleontology is like a police investigation into the history of the world—we need to gather as much evidence as possible."

Mastodon and mammoth teeth

To the experts at the UI, fossils reveal critical information about creatures that lived thousands of years ago. These 15,000-year-old molars indicate that mastodons browsed trees while mammoths grazed grasses. Fossils of these extinct Ice Age (Pleistocene) creatures resembling elephants have been widely found across Iowa.

Collectors' corner

The UI's enormous fossil collection encompasses all shapes and sizes. Despite having worked with the collection for more than seven years, paleontology repository manager Tiffany Adrain admits that even she hasn' been able to investigate the contents of every drawer, cupboard, or file. Unsuspected treasures may still lurk there, waiting for a lucky researcher to stumble upon them and rewrite history.

Ammonites from the Jurassic Period of England

The paleontology repository contains thousands of ammonites and nautiloids from all over the world, collected by UI faculty. Each specimen has its own unique catalog number, and a major project funded by the National Science Foundation is under way to make specimen records and photographs available on the Internet.

Spiney trilobite from Platteville, Iowa

Some 440-480 million years ago, during the Ordovician period, Iowa lay beneath seas filled with these now-extinct marine animals. The size of the UI's trilobite collection has more than tripled over the last eight years thanks to the efforts of associate professor Jonathan Adrain and his geosciences students.

Floyda gigantea

As befits a piece of Iowa history, this giant snail from the Devonian Period is named for Floyd County in the northeastern part of the state, where it was found. Along with many other specimens, it was discovered by local collector and promising paleontologist Charles Belanski, who died at an early age in 1929. The specimen shown here is cut and polished to show its interior whorls.

Cyathophyllum robustum from Iowa City

Collected by legendary UI professor Samuel Calvin in the late 1800s, this Devonian horn coral was photographed by student Gilbert Houser for his 1892 Master of Science thesis. A pioneer in the use of photography in science, Calvin encouraged his students to use this new method of illustrating specimens.

Holotype specimen of the snail species Holopea grandis

When fossil collectors discover new species, one specimen is designated as the "holotype" upon which the official description is based. Samuel Calvin discovered, named, and described this new species of snail in 1890. He recorded it in his handwritten ledger as specimen No. 521 from the Silurian of Monmouth, Iowa.

Holotype specimen of the crinoid (sea lily) Platycrinites cranei from the Mississippian Age, from Gilmore City, Iowa

The paleontology repository contains more than 1,200 holotype specimens, more than half of which are from Iowa. Samuel Calvin's collection, which now forms the basis of the repository, was developed so that the professor could use actual fossils in the classroom to teach students about paleontology.

Type specimens of the Mississippian Age crinoid Rhodocrinus octadactylus from Le Grand, Iowa

Fossil sea lilies—animals related to starfish and sea urchins—are very common in the marine rocks of Iowa. At one time, enthusiasts proposed that they be adopted as the State Fossil of Iowa.

Sigillaria calvini

Another fossil discovered by Samuel Calvin—in Iowan coal swamps dating back to the Pennsylvania period, some 320-290 million years ago—this one also bears his name. Calvin gave the specimen to his colleague and former student, botanist Thomas Huston Macbride, who, in 1907, named this new species Sigillaria calvini.

Taxi driver trilobite

UI paleontologists are at the forefront of paleontological research and continue to add new species to our knowledge of the history of life on Earth. With so many species to name, they often resort to a creative approach. UI associate professor Jonathan Adrain has tagged some of his finds with the names of rock stars, including Joey Ramone, and celebrity dogs. When Salt Lake City taxi driver Al Sacharov jokingly offered Adrain a free taxi ride to the airport in exchange for his name immortalized in scientific circles, the professor obliged with Bearriverops alsacharovi. This delicately preserved, tiny trilobite (shown here with its head and tail) is about the size of an apple seed.