Out of the Quarry:

More Signs of a Supercontinent

For the past six years paleontologist David Berman of the Carnegie Museum of Natural History has been searching for evidence that animals of 280 to 260 million years ago lived in a world in which all the land masses formed a supercontinent called Pangaea. His research during the past three decades into this period, the Early Permian, has led him into an interesting chapter of the prehistoric world in which the animals with backbones—vertebrates—first left behind their watery world of rivers, swamps, and lakes, and successfully invaded the land. There they evolved into a great variety of plant-eating and carnivorous forms that were the ancestors of the rich terrestrial life of dinosaurs, birds, amphibians, and mammals that we know about.
The theory that a supercontinent once existed, and then divided into giant pieces that gradually separated by continental drift, continues to accumulate evidence from geologists. But the biological evidence for this important event is far from convincing. Can paleontologists find the same animals in the fossil records of today’s different continents to prove that these creatures once shared a single, common supercontinent? In fact, they can, and David Berman, working in quarries of Early Permian rocks in the American West and in Europe, is one of the paleontologists finding this new evidence.

Until very recently the history of Early Permian land-dwelling vertebrates has been almost entirely documented by fossils found in the United States. However, since 1993 David Berman, along with colleagues Dr. Stuart S. Sumida from California State University at San Bernardino and Dr. Thomas Martens from the Museum der Natur in Gotha, Germany, have been unearthing the first superbly preserved examples of strictly land-dwelling, Early Permian animals in Germany. These animals are identical to those found by Berman across the United States. This similarity is the first undeniable biological evidence that North America and Europe were once joined in a continuous landmass. The site of this remarkable discovery is the Bromacker quarry in the Thuringian Forest south of Gotha, in eastcentral Germany.

One recently unearthed example of a global-wide inhabitant from the Bromacker quarry is a bizarre, plant-eating animal called Diadectes. Nick-named the “Permian cow” because of its large size (reaching ten feet in length) and barrel-shaped trunk, Diadectes is the oldest known animal restricted to a diet of land plants. Its wanderings have been documented from the southwestern United States to West Virginia, and now across the Atlantic Ocean in Germany.
A pair of complete skeletons of the amphibian Seymouria from the Bromacker quarry offers even more proof of continental drift. Known previously only from southwestern United States, the museum’s Benedum Hall of Geology displays a block of rock with five excellent skeletons that were collected by Berman in New Mexico in the early 1980s. The Bromacker specimens were shipped back to Pittsburgh for the museum’s preparator Amy Henrici to “prepare,” since Carnegie Museum of Natural History is known worldwide for its excellence in removing fossils from the hard surrounding matrix of rock.

As might be expected the Bromacker quarry has yielded some uniquely different animals. Easily the most fascinating new-to-science animal recovered so far is a 10-inch long reptile. Many features of its skeleton, such as its extraordinarily long tail and long hindlimbs, and its relatively short forelimbs, indicate that it was probably capable of dashing about in a semi-erect posture on its hindlimbs, perhaps to chase down slower insects for food or sprint away from predators and avoid being eaten. If true, this creature predates the next oldest known animals capable of two-legged locomotion (including dinosaurs) by perhaps 70 million years.
This paleontological research has been supported by The National Geographic Society, the Graham Netting and Edward O’Neil research funds of the Carnegie Museum of Natural History, NATO, and the Museum der Natur Gotha in Germany.

—R. Jay Gangewere

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