The redevelopment of a played-out clay pit in Prince George's County will include an unexpected bonus for paleontologists and school kids: a dinosaur park.
The developer of an industrial park on the site has donated 7 1/2 acres of the 700-acre Muirkirk property for a public dinosaur preserve, complete with ancient tree species and an exposed layer of clay that has yielded up bits of dinosaurs for more than a century.
One of the latest finds - kept quiet for almost a year while the land was transferred to the government and fenced - was the 2-foot-long leg bone of a still-unidentified plant-eater. It's one of the largest and most complete dinosaur bones ever unearthed in Maryland.
"Whatever it turns out to be, we don't already have one. That's very important to us," said Matthew Carrano, curator of dinosaurs at the Smithsonian Institution's National Museum of Natural History. "Even though we know dinosaurs were here in Maryland, it still fairly rare to pull one of these things out."
The bone was discovered last September by amateur paleontologist Michael Styre, 46, a cabinet installer from Laurel who from time to time visits the pit to hunt for fossils.
On this trip, he spotted a small portion of bone protruding from a spot where rain had eroded part of a trail used by trespassing motorbikers. "That led to the rest of it," Styre said. "I started digging it out a little more."
He quickly realized the bone was too big to be excavated safely by an amateur, so he stopped and called Washington, D.C., geologist Peter Kranz, an expert on Maryland dinosaurs. Kranz called the Smithsonian.
Parts of the pit were mined for iron in the 1860s. But around 1900, the owners began mining the clay for tile and later for brick manufacturing. The quality clay eventually ran out, however, and the General Shale Co. produced the last brick in 1990.
The land was sold in 2005 to Jackson-Shaw, a Dallas development company with offices in Lanham. Tom Aylward, its vice president for development, said the company is installing a road, water and sewer lines, and has begun the first of 11 planned light industrial buildings.
Eventually, the project will include a retail area and a business park. In July, the company transferred the wedge of land that includes the dinosaur deposits to the Maryland-National Capital Park and Planning Commission.
Jackson-Shaw plans parking for a few cars and a school bus, with seating, protective fencing and walkways to provide safe public access to the area. Aylward said the landscaping will include living descendants of plants that grew there in the time of the dinosaurs.
"You'll pass a grove planted with ginkgoes and ferns ... prehistoric plants that are alive today and in the fossil record," he said. Aylward expects his company will spend about $125,000 at the site. Public access might be possible by next spring, but it will be 2009 before the park is completed.
"It's the right thing to do; it's kind of exciting," said Aylward, who took his wife and daughter last year to watch the dinosaur bone excavated from the clay.
"This is something somebody else might have bulldozed right through," he said at the time. But the company conferred with paleontologists and became convinced of the value of preserving the exposure for study and education. "It gives them something to work on for 75 or 100 years," he said.
The Park and Planning Commission, which owns some wooded land adjacent to the site, has $250,000 allocated for future development and educational programs there but has no firm plans yet, said park planning supervisor Charles Montrie.
"We appreciate Jackson-Shaw working with us for the preservation of the resource," he said. "He [Aylward] was under no obligation to do anything."
Maryland's tourism and Natural Resources officials have been considering Kranz's proposals for development of dinosaur- or fossil-themed tourist sites across Maryland. They could be linked by a multistate "Dinosaur Trail" and promoted through maps and brochures under Maryland's Scenic Trails program, Kranz has said.
The Muirkirk site includes an eroding slope that exposes the buried layer of Cretaceous clays.
A hundred million years ago, the area was a lush, warm and wet landscape similar to southern Louisiana, said Kranz, who long championed the development of a dinosaur park alongside the clay pit.
Since he began the first systematic, scientific fossil collecting at the site in 1988, Kranz has found dozens of bits of dinosaurs, turtles and early mammals, including teeth, bones and shells, as well as bits of wood and cones from cypress trees, cycads, ferns and a variety of ancient plants.
He followed in the footsteps of Philip Tyson, the state agricultural chemist, who in 1859 found a large tooth from a dinosaur later formally described and named Astrodon johnstoni. In the 1880s, scientists began digging up more dinosaur bones in the area.
In 1991, amateur paleontologist Arnold Norden and his children discovered a 4-foot segment of a 6-foot dinosaur femur sticking out of the eroding clay. It was excavated by experts from the Smithsonian, who determined that it, too, had belonged to Astrodon. It was the largest dinosaur bone ever excavated in the Eastern United States and is now on loan to the Maryland Science Center.
Astrodon has since become Maryland's state dinosaur, but the name has recently been the subject of some debate. Some scientists prefer to call it Pleurocoelus, but others say neither name is justified yet because so few representative fossils have been recovered.
Prince George's County has also produced hundreds of animal footprints from the Early Cretaceous period, 135 million to 95 million years ago. Another dinosaur femur was found in related clay deposits in southeastern Baltimore County in 1989.
The leg bone found last September measured 2.1 feet long and about 6 inches across. "It's pretty awesome, the biggest thing I ever found," Styre said.
Peter Kroehler, a Smithsonian preparator, went to the clay pit last Sept. 12 to remove the fossil before the elements destroyed it. Aylward allowed journalists to observe the bone's excavation on condition that the find not be disclosed until the land was transferred and fenced.
As the others watched, Kroehler and an assistant, Kara Reich, carefully uncovered the rest of the bone and covered it in wet paper towels. Then they encased it in plaster-soaked burlap strips reinforced with a length of wood, like a splint.
"The bone is so fragile, if we were to try to get it out [without the plaster and wood support] it would probably fall into 20 or more pieces," Kroehler said.
After the plaster hardened, the 30-pound package was safely transported to a Smithsonian lab. A year later, Reich and another volunteer are still working to remove rock and clay "matrix" attached to the bone. It's looking to Kroehler like a lower leg bone - a fibula, perhaps. And it's nearly complete, "a really nice dinosaur bone," he said.
It will need more cleaning before anyone will try to identify the species it belonged to. Kroehler suspects it's from a plant-eater, perhaps a horse-sized duck-billed hadrosaur.
Carrano, the Smithsonian dinosaur curator, hopes one day the bone can be displayed in a soon-to-be-renovated dinosaur hall at the museum.
"One thing we've talked about is showing people local dinosaurs in addition to the classics," he said. "This certainly will be a strong candidate to be displayed. It's sizable and important, nice-looking and better preserved than most."