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.

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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...

Teeth and Jaw of an Ancient Shark
Mar 21, 2013 - 9:20AM
This well-preserved fossil is the only intact partial skull ever found of a...

Megalodon Teeth
Feb 26, 2013 - 10:35AM
Two fossilized teeth from a megalodon (Carcharodon megalodon) dating back...
Teeth and Jaw of an Ancient Shark
Mar 21 2013 - 9:20am
This well-preserved fossil is the only intact partial skull ever found of a white shark that lived about 6.5 million years ago called Carcharodon hubbelli. The fossil jaw contains 222 teeth, some in rows up to six teeth deep, and may provide evidence that modern day great white sharks evolved from...
A Mississippian Marine Habitat (359 - 318 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...
The Whale Family Tree
Jan 26 2010 - 11:45am
This family tree shows how the ancestors of whales moved gradually from land to sea. Early whales took advantage of abundant marine resources. Baleen whales evolved later as polar climates cooled and marine resources became more concentrated, making filter feeding effective. Learn more at "Did...
Panama Expedition Success
Jun 22 2011 - 5:44pm
Paeleobiologist Dr. Nicholas Pyenson, Curator of Fossil Marine Mammals for the Smithsonian's National Museum of Natural History (NMNH), set out with Jorge Velez-Juarbe, NMNH Research Student and Ph. D. Candidate at Howard University and Aaron O'Dea from the Smithsonian Tropical Research Institute...
Ancient Great White Shark
Jan 26 2010 - 11:45am
A scientific illustration of the most powerful fish of its time, Carcharodon megalodon, which swam the ocean 30 million years ago.  This shark may have reached a size of 20 meters/66 feet. Meet other ancient top predators and modern great white sharks.
Megalodon Teeth
Feb 26 2013 - 10:35am
Two fossilized teeth from a megalodon (Carcharodon megalodon) dating back more than 20 million years.
Bones and Teeth of South America's Oldest Fossil Whales
Sep 12 2011 - 2:55pm
These are fossil remains of archaeocetes, ancient whales, from the Paracas Formation of Peru's Pisco Basin. Smithsonian paleobiologist Nicholas D.
Whale fossils on the mainland, and into a CT scanner
May 21 2012 - 1:23pm
After a few long days of hard work on the island, we were finally able to excavate and remove, not just one, but two skeletons of an early "toothed" baleen whale from the rocks near the Carmanah Lighthouse. All told, it took our team 3 days, along with assistance from Parks Canada, a chartered...
Evolution of Whales Animation
Evolution of Whales Animation
Sep 30 2009 - 11:21am
Whales have existed for million of years. Watch this animation, from the Sant Ocean Hall, to see how they evolved from land-dwellers to the animals we know today. Discover more about whale evolution in our Ocean Over Time interactive. Note: this video contains no audio.
Illustration of a New Fossil Whale, Bohaskaia monodontoides
Mar 8 2012 - 3:49pm
A reconstruction of a new fossil beluga relative, Bohaskaia monodontoides, described by Smithsonian scientists, is in the foreground. Its living relatives, the beluga and narwhal, are illustrated left to right in the background. The coloration of the extinct whale is speculative.
Arm Bone Fossil of an Ancient Toothed Whale
May 11 2012 - 11:46am
Nick Pyenson, curator of fossil marine mammals at the Smithsonian's National Museum of Natural History, holds an arm bone from a "toothed" mysticete from Vancouver Island. This is the second specimen found at this locality on the remote western side of Vancouver Island. Nick used a rock saw to...
Foraminifera
Mar 25 2010 - 4:23pm
Microscopic, single-celled organisms called foraminifera have a fossil record that extends from today to more than 500 million years ago. Although each foram is just a single cell, they build complex shells around themselves from minerals in the seawater. These shells have accumulated in layers of...
Digging a Trench
Jun 22 2011 - 2:48pm
Paeleobiologist Dr. Nicholas Pyenson, Curator of Fossil Marine Mammals for the Smithsonian's National Museum of Natural History (NMNH), set out with Jorge Velez-Juarbe, NMNH Research Student and Ph. D. Candidate at Howard University and Aaron O'Dea from the Smithsonian Tropical Research Institute...
Ancient Entoproct Community
Jan 18 2013 - 10:28am
For a long time, scientists thought that some small tentacled fossils were early ancestors of jellyfish. But a new study has found that these ancient animals are actually related to an entirely different group of animals: the entoprocts, which are still alive today. The new fossil (Cotyledion...
So You Think You're Smarter Than a Cephalopod?
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.
Fossils Get a CT Scan
May 22 2012 - 4:33pm
When paleontologists, like the Smithsonian National Museum of Natural History's own Nick Pyenson, curator of marine mammal fossils, dig up fossils in the field, they can't just toss them in their backpacks and carry them home because the fossils are too fragile. One method they use to protect the...