Chile Fossils a Whale of a Discovery

ChileThe discovery of whale fossils in the Atacama Desert in Chile happened four years ago, but it is making news this week. Results of the discovery by workers expanding the Pan American highway have been published by a Royal Society journal, and the scope of the findings is gargantuan.

Even before the latest discovery, the site where the bones were found was already dubbed Cerro Ballena, which translates into “Whale Hill,” but this find went far beyond what scientists could have imagined. The new dig at Cerro Bellena produced over 40 whale skeletons, all nearly complete and in similar death poses, belly up and facing in the same direction.

Excavation of the site proved to be the biggest challenge for the team of researchers who worked the site, headed up by Nicholas Pyenson, curator of fossil marine mammals for the Smithsonian Natural History Museum. The team was given only a two-week window to work the site before workers would return to continue their construction, so Pyenson’s first order of business was to send in technicians to make a 3-D image of the skeletons’ arrangement so they could print replicas later. The bones were then shipped to several museums where they would be examined by scientists.

One of the most significant aspects of the whale fossil discovery in Chile was the fact that they were all found in the same location. Historically, whale fossils are found singularly. The grouping and the belly up posture suggested that all of the whales died from the same fate. The researchers’ best guess is that they all succumbed to algal blooms, or red tides, either contained in their prey or inhaled themselves. As the whales weakened and died, the configuration of the coastline created a natural funnel and sucked the mammals into an estuary and eventually onto the beach where they decomposed and were buried. At that time Cerro Ballena was an ocean cove but was lifted to 120 feet above sea level when the Andes Mountains were created by massive tectonic shifts.

Of further interest was the fact that the sea mammals were found in four different mass graves at separate levels. The burials are thought to have occurred at four different times within the span of 10,000 years, with the first one occurring from six to nine million years ago, late in the Miocene epoch.

Beyond the whale grouping were other discoveries for the excavators, including a now-extinct species of sperm whale, a walrus-like whale with teeth, two seals and rare aquatic sloths. Pyenson was amazed at finding so many marine-mammal fossils in such a small area of South America. Even more incredible was the condition of the subjects, as almost all of the skeletons were found completely intact. Many were perfect, with only the occasional nick from wandering crabs.

The importance of the whale fossil discovery at Cerro Ballena in Chile now extends beyond the latest archaeological excavation. The discovery puts “Whale Hill” on the map as one of the most fossil-rich areas in the world. Pyenson places it in the same class now as sites like the La Brea Tar Pits in California and Dinosaur National Monument on the Colorado/Utah border. The University of Chile in Santiago is in the process of building a research station at Cerro Ballena where Pyenson and other researchers hope, and expect, to uncover hundreds of more links to our prehistoric past.

By Chuck Podhaisky

History
NPR
BBC

 

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