That same year, his team discovered Nigersaurus taqueti, a 110-million-year-old, plant-eater with hundreds of needle-like teeth and a head shaped like a standing vacuum cleaner. Known to researchers as the "fern-mower," this sauropod was described in a paper published in the November 1999 issue of Science.
"These are weird animals. If you're familiar with North American dinosaurs, which is what most people are familiar with, these animals look really different from what they're used to," said Gabrielle Lyon, Sereno's wife and research partner.
Beyond dinosaurs, Sereno and his colleagues have discovered new species of other ancient animals from turtles to pterosaurs. One dwarf crocodilian was the size of a cracker.
In 1997 Sereno's team found the best fossil example yet of Sarcosuchus imperator, a 110-million-year old crocodilian that weighed ten tons (nine metric tons) and munched fish and perhaps small dinosaurs through jaws six-feet (two-meters) long. Dubbed "SuperCroc," the armor-plated behemoth was the size of a school bus.
Important on their own, these individual discoveries have helped Sereno piece together a larger view of life and evolutionary change in ancient Africa.
At the American Association for the Advancement of Science annual meeting last year, Sereno said that, based on his findings, he believed the ancient supercontinent of Pangea may have separated into its various subcontinents much more slowly than previously thought.
During his most recent expedition this fall (sponsored in part by the National Geographic Society), Sereno and his team pressed to explore the most recent chapter of Africa's dinosaur history, the period around 90 million years ago.
In the field, Sereno's team found a new long-necked sauropod and other animal species, including ancient crocodilians and turtles. They also returned to the site of neolithic human remains (surrounded by artifacts over 5,000 years old) briefly visited during a previous expedition. This year, the team was shocked to discover nearly 130 skeletons at the site.
As the sands howled around his Land Rover, Sereno said that he was living a life of adventure and discovery he never dreamed would be possible as a young adult.
As for Africa, his sense of accomplishment was evident. "Here we are ten years later, a menagerie behind us and a whole bunch of stuff wrapped up to release," he said.
There's no sign the parade of beasts will stop any time soon. Talking into his satellite phone, Sereno explained that his crew had just pulled up to hills 80 million years old. The area is rumored to hold dinosaur bones, but had never been explored by paleontologists, he said.
"We have no idea if we're going to find anything," he said. "But we can't wait to walk around."
SOURCES AND RELATED WEB SITES