Since construction began in 2011 on the new dam for the Calaveras Reservoir near Malpitas, California, construction crews and paleontologists have unearthed an impressive collection of fossils dating as far back as 20 million years.
Paleontologist Jim Walker tells the San Jose Mercury News that the collection of fossils give scientists an idea of what the area, now a remote canyon covered mostly with rock and dirt and a smattering of trees, was like during the Miocene Epoch—when it was all underwater.
Walker said the area used to be a beach and fossils of sea creatures were being discovered before construction even started.
The first discoveries were scallops. But in the three years since then, 529 fossils have been discovered at the site including clams, barnacles, nine whale skulls, what crews hope is a whole whale skeleton, the teeth of the now-extinct hippopotamus-like creature called Desmostylus and the teeth of a 40-foot-long
shark. Some of the scallops fossils found are as big as dinner plates, the Mercury News reports.
The construction itself is a $700 million project to replace a dam at Calaveras Reservoir built in 1925 with one more capable of standing up to earthquakes. Crews are still in the excavation phase of the project and so far have removed 5 million cubic yards of dirt amounting to a 500-foot hole in front of the old dam. The phase is about 60 percent complete.
The original project only had a budget of $409 million with a completion date of 2015. However, workers uncovered two ancient landslides that required them to remove all the aforementioned earth to ensure construction of the new dam is safe.
Crews hope to have the dam construction completed by 2018. By then, many of the fossils crews have uncovered could be on display in a yet-to-be-determined San Francisco-area museum.