You Have to Try This When You Go to the Beach‼️😱 When you’re walking the Oregon coast, some of those weird rocks under your feet are actually pieces of an ancient Miocene ocean. The Astoria Formation is around 15 to 20 million years old, and it can hold all kinds of fossils: scallops, clams, snails, tusk shells, petrified wood, crab pieces, shark teeth, dolphin or whale bones, seal and sea lion relatives, and even whole crabs hiding inside concretions. Oregon State University’s Oregon Sea Grant says these coastal fossil beds include everything from microscopic algae to hand-sized clams and dinner-plate-sized scallops. And here’s the shocking part: scientists don’t just look at a fossil and guess its age. They compare the rock layer it came from, the known fossil species inside it, magnetic reversals locked in the sediment, and volcanic material around the formation. One OSU-linked study on the Astoria Formation used paleomagnetic sampling, which looks at ancient magnetic direction changes preserved in the rocks, then compared that pattern to the global Miocene magnetic timeline. They also used the age of nearby volcanic basalt, dated around 15.4 million years old, to help lock in the timing. So that random shell fossil you find near Newport might not just be “an old clam.” It could be a tiny fossil receipt from an ancient Oregon coastline, back when whales, sharks, crabs, and strange marine mammals were cruising through the Pacific long before humans ever stepped foot here. #Learning #Education #Animals #Nature #Fossils - @jake.pnw