Whales in the desert: Fossil bonanza poses mystery
By EVA VERGARA and IAN JAMES | AP – 4 hrs ago
SANTIAGO, Chile (AP) — More than 2 million years ago, scores of whales congregating off the Pacific Coast of South America mysteriously met their end.
Maybe they became disoriented and beached themselves. Maybe they were trapped in a lagoon by a landslide or a storm. Maybe they died there over a period of a few millennia. But somehow, they ended up right next to one another, many just meters (yards) apart, entombed as the shallow sea floor was driven upward by geological forces and transformed into the driest place on the planet.
Experts say other groups of prehistoric whales have been found together in Peru and Egypt, but the Chilean fossils stand out for their staggering number and beautifully preserved bones. More than 75 whales have been discovered so far — including more than 20 perfectly intact skeletons.
They provide a snapshot of sea life at the time, and even include what might have been a family group: two adult whales with a juvenile between them.
"I think they died more or less at the same time," said Nicholas Pyenson, curator of fossil marine mammals at the Smithsonian's National Museum of Natural History.
Other unusual creatures found elsewhere in the fossil-rich Atacama Desert include an extinct aquatic sloth and a seabird with a 5-meter (17-foot) wingspan, bigger than a condor's.
Erich Fitzgerald, a vertebrate paleontologist at Museum Victoria in Melbourne, Australia, emailed that the latest find is very significant.
Hans Thewissen, an expert on early whales, agreed. Another scenario, he said, is that the whales might have gathered in a lagoon and then an earthquake or storm could have closed off the outlet to the ocean.
"Subsequently the lagoon dries up and the whales die," said Thewissen, a professor of anatomy at Northeast Ohio Medical University. He said the accumulation of so many complete skeletons is "a very unusual situation."
"If this were a lagoon that dried up, you might see signs that ocean water evaporated," such as crystallized salt and gypsum in the rock, said Thewissen, who is not involved in the research. "On the other hand, if a giant wave or storm flung the whales onto shore, it would also have pushed the ocean floor around, and you would see scour marks in the rocks."
Dating fossils is complicated, experts said, and it will be very hard to distinguish dates precisely enough to determine whether the whales all died simultaneously.