On the horizon
Australian paleontologists have uncovered a wealth of new fossils that shed light on the demise of some of the continent's most remarkable animals some 40,000 years ago. The new finds help rule out changing climate as a leading trigger for their extinction, the team says, leaving open the likelihood that humans played a significant role.
Prior to humans arriving, Australia's "megafauna" included 10-foot-tall, 400-pound kangaroos and wombatlike animals that were more than six feet tall at the shoulders and weighed two tons. Researchers are still puzzling over why such creatures vanished.
Scientists found the fossils in caves beneath south-central Australia's Nullarbor Plains. The fossils – many of them whole skeletons – are so well preserved that the researchers say it is unprecedented in Australia. Among the finds: Eight new species of kangaroo, including two tree kangaroos. The diversity of the group, which the team dates to roughly 200,000 to 400,000 years ago, suggests that the region had more varied plant life than it does today. But several lines of evidence suggest that the region was dry, even then. This renders untenable the notion that these megafauna were vulnerable to arid conditions, the team says. Many of the species vanished by the time humans arrived or soon after. The report appears in Thursday's issue of the journal Nature.
In the 18th century, master paint mixer Heinrich Diesbach stumbled upon the color Prussian blue. Today, a team of French chemists might say: Thanks for the memory.