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Like the modern nautilus, this relative of modern squid hunted from inside the safe haven of a protective shell. Ammonites went extinct around the same time as the dinosaurs—65 million years ago. Find more...
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What makes a top predator? Razor-sharp teeth? Speed? Strength? Size? Who is the...
About 100 million years ago , during the heyday of the dinosaurs, reefs were...
For a long time, scientists thought that some small tentacled fossils were...

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These "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. And many often grew together to form...
How long have jellyfish lived in the ocean? This jellyfish fossil is from...
Today, filter feeders like clams, sponges, krill, baleen whales, fishes, and...

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Whales swim, but their ancestors walked. Whales are mammals (like us) whose ancestors lived on land. Life probably began in...

The Ocean Blog

Like the modern nautilus, this relative of modern squid hunted from inside the safe haven of a protective shell. Ammonites went extinct around the same time as the dinosaurs—65 million years ago...
The basic body plans of all modern animals were set during the Cambrian Period, 542 - 488 million years ago. Your friends, family, and pet turtle may not look much like the creatures here. But we and...
Today, filter feeders like clams, sponges, krill, baleen whales, fishes, and many others fill the ocean, spending their days filtering and eating tiny particles from the water. But when did the first...
These deep-sea sediment cores were drilled from beneath the seafloor, and hold information about millions of years of ocean and atmospheric chemistry. As dirt, dead organisms, and other particles...
Offshore Peru, during the Eocene (~56-34 million years ago), showing three archaeocetes (ancient whales), along with a previously described fossil penguin. Top to bottom: Perudyptes devriesi ,...
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...
During the late Cretaceous period, Kansas was covered by a vast sea. There, scientists have found fossils of Squalicorax sharks (also called crow sharks) that lived 70-80 million years ago. They were...
This illustration shows one old idea of what the ancient shark Helicoprion might have looked like. There once was room for many ideas—some more plausible than others—because the only fossils of the...
Not all fossils from the Cambrian period became amulets; instead the extinct Hallucigenia sparsa was notable for its spines.
The Ottoia prolifica has proven that cannibalism did exist in the Cambrian period since there have been portions of one Ottoia prolifica found in another specimen’s gut.
Lenticulina secans -- this foram lives on the seafloor. This specimen was collected from ocean sediments in southeast Tanzania. It comes from a time over 92 million years ago when both the polar...
Evidence shows that life probably began in the ocean at least 3.5 billion years ago. Photosynthesis began more than 2.5 billion years ago—the Great Oxidation Event. But it took hundreds of millions...
Where ocean currents were strong, ancient rudist “recliners” lay unattached on the seabed. Notice the pink tentacles, which were used to filter feed. Learn more about ocean life throughout deep time...
Opabinia was a strange looking creature: it had five mushroom-like eyes that allowed it to see predators approaching from many directions.
Most people have never heard of the Hawaiian petrel , an endangered, crow-sized seabird that spends the majority of its life searching for food over the North Pacific Ocean. Nevertheless, this bird...
Humans are late arrivals on Earth. For nearly 75% of Earth’s history, life consisted of single-celled microbes without a nucleus (prokaryotes). Volcanoes and erosion sculpted Earth 3.5 billion years...
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...
Ocean Overtime Timeline.
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