Boning Up Leads to Sloth as a Student Makes a Rare Find
07/03/1989 at 01:00 AM EDT
The day didn't start off well for Daniel Delgado, 23, a University of Florida junior. Because of tight scheduling between a financial-aid interview and an introductory geology class field trip, he didn't have time to go home to pick up his digging tools. And a geologist without his rock hammer is about as much good as a canoeist without a paddle.
When his class reached the dig, a limestone quarry 10 miles from the Gainesville campus, Delgado's spirit sank further; the students would be searching for fossils in a rockbound site. "I thought I could borrow a tool, but no one had one to spare," he reports. "You can't dig in rocks with your fingers." So Delgado wandered off alone to a place about a half mile away where he spotted a limestone wall containing a layer of clay. Hanging by one arm some 25 feet up, he dug into the soft sediment with his free hand, and there it was—a bone and then another, each a dinner-plate-size oval about five inches thick. "I almost fell off the wall," he says.
Fetched by the excited Delgado, others in the digging party came over to pitch in, and Prof. Paul Cisielski immediately recognized the bones as vertebrae of a long-extinct giant ground sloth. The professor allowed his class to uncover some more bones "to experience the thrill of the discovery" and then called a halt, knowing that inexperienced diggers were likely to damage the site for future excavation. They left all their finds in place—except a half dozen bones—and returned to campus.
There scientists verified the bones as the remains of a rare Eremotherium sloth, in this case a 15-foot specimen that lived around 2 million years ago. A distant cousin of today's South American tree sloth, giant sloths were lumbering vegetarians that became extinct about 10,000 years ago, probably as a result of climatic changes or over-hunting by humans. Further excavation revealed that Delgado had stumbled on a complete skeleton, the oldest of this species found to date—and that another one lay just below it, with part of a third nearby.
Delgado acknowledges that his achievement, now classified a "major find" by experts, owed a lot to beginner's luck. The Miami-born son of an auto-body repairman, Danny had been planning to go to medical school. But since his amazing chance find, he's wavering ever so slightly on his career path. "If someone were to offer me a scholarship to study paleontology," he says, "I would consider it."