The Ocean Through Time

Life began in the ocean around 3.5 billion years ago and as evolution progressed, many species went extinct -- and some left behind fossils -- as others appeared. And even now, the ocean hasn't stopped changing as evolution continues and humans leave their mark.

LATEST TODAY'S CATCH

Elevator Rudists

May 1, 2013 - 9:48AMThese "elevator" rudists, an ancient bivalve, used one long heavy valve to anchor themselves in the sediment. They used their tentacles (shown here in pink) to filter food from the sea water. Discover more about the ancient...
Mar 21, 2013 - 9:20AM
This well-preserved fossil is the only intact partial skull ever found of a...
Feb 26, 2013 - 10:35AM
Two fossilized teeth from a megalodon (Carcharodon megalodon) dating back...
Sep 12 2011 - 1:10pm
CREDIT: Smithsonian Arctic Studies Center Basque Whalers Background Having already learned to hunt large whales in the Bay of Biscay in the 13th through 15th centuries, Basques began arriving in the rich whaling grounds of southern Labrador, Newfoundland, and the Gulf of St. Lawrence...
May 5 2011 - 4:41pm
The blanket octopus can rip a poisonous tentacle from a Portuguese man-o-war and wield it like a sword to ward off enemies as it soars through the ocean trailing its webbed cloak behind it.
Nov 16 2012 - 6:05pm
For the last 150 years, paleontologists have debated the origins of the great white shark. Many believe that they descended from the 50-foot megalodon, also known as the megatooth shark (Carcharocles megalodon), which is often imagined to be a vastly inflated great white. But after the discovery of...
Really Small Fry  Shifting Baselines in Marine Fish Stocks
Dec 4 2009 - 1:06pm
A public service announcement uses a dramatic example to emphasize that ocean fish aren’t as big as they used to be. Find out more about the decline in the ocean's top -- and often large -- predators in a recorded talk by marine ecologist and National Geographic explorer Enric Sala.
Sep 30 2011 - 6:38am
Smithsonian curator of fossil marine mammals Nick Pyenson and a team of collaborators are heading into Chile's Atacama Desert, shown here. They'll study a rich bonebed of fossil marine vertebrates that lived off the Chilean coast around 8 million years ago.
Sep 20 2011 - 4:36pm
Crinoids (echinoderms related to sea stars and sea urchins) dominate the Paleozoic shallow water habitat in this illustration. They evolved a variety of stalk heights, which enabled them to capture food at different levels above the sea floor. The base of their stalks was modified to anchor the...
Aug 15 2012 - 9:45am
The fossil tooth whorl of the ancient shark Helicoprion, dating back 290 million years before present. For a long time, people didn't know what the shark looked like—but, thanks to a CT scan of a fossil, researchers finally put the pieces together in 2013. Read more about this story in our ...
Sep 12 2011 - 11:43am
Offshore Peru, during the Eocene (~56-34 million years ago), showing three archaeocetes (ancient whales), along with a previously described fossil penguin.