Friday, November 20 3:51 pm
Fossil Hunting Among Volcanoes With Paleontologist John Flynn
This year, scientists at the American Museum of Natural History are celebrating the 200th anniversary of Charles Darwin’s birth and the 1859 publication of On the Origin of Species with a collection of vignettes describing expeditions and ideas with links to Darwin’s seminal work.
It was during a siesta in the woods that Charles Darwin, exploring the Chilean coast more than three years into his voyage on the H.M.S. Beagle, was shaken by one of the strongest earthquakes known to the local inhabitants. On that February day in 1835, Darwin not only witnessed “the most awful spectacle I ever beheld… [with] not one house left habitable,” as he wrote to his sister Caroline, but he also had an epiphany:
The most remarkable effect of this earthquake was the permanent elevation of the land… [which revealed] mussel-shells still adhering to the rocks, ten feet above high-water mark.… At Valparaiso… similar shells are found at the height of 1,300 feet: it is hardly possible to doubt that this great elevation has been effected by successive small uprisings.
Chilecebus, a reconstruction of which is shown above, is one of the fossils that John Flynn and colleagues have uncovered in the Chilean Andes (Illustration by Velizar Simeonovski, courtesy of John J. Flynn)
While sailing across the Atlantic and past Tierra del Fuego, Darwin had been reading Charles Lyell’s Principles of Geology, in which Lyell laid out the case that massive geological change is based on the slow accumulation of minute changes over time. It was through this lens that Darwin observed the volatile, shifting landscapes that partly informed his theory of evolution.
We now know that the active geology of Chile—the earthquakes, volcanoes, and formation of the Andes Mountains themselves—is caused by the squeezing of the Pacific Ocean plate under South America and back into the Earth’s interior. Paleontologist John Flynn and colleagues André Wyss, Reynaldo Charrier, and Darin Croft have traversed this geology over the last 20 years to learn more about both the history of the Andes and the unusual extinct fauna that lived on this former island continent. Mountain uplift drives fossil beds to the surface, weathering exposes fossil teeth and bone, and volcanic debris dates their time frames.
“We were first drawn to Chile because amateur naturalists found whale bones at 6,000 feet in the 1980s,” says Flynn. “Since then, we’ve uncovered a remarkable mammalian menagerie that explains some of the diversity seen today and also helps us understand more of the uplift history of this 5,000-mile-long mountain chain that forms a spine along then entire western edge of South America.” Read more »
