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How long have jellyfish lived in the ocean? This jellyfish fossil is from the Cambrian period, more than 500 million years ago. It was found buried in Utah —an area that used to be...
Like the modern nautilus, this relative of modern squid hunted from inside the...
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What makes a top predator? Razor-sharp teeth? Speed? Strength? Size? Who is the...

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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...
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

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...
This illustration shows the edge of a warm inland sea during the Cretaceous Period, heyday of the dinosaurs. Constantly shifting sediment supported new groups of organisms, including rudist clams—...
The Wiwaxia corrugata may have molted its scales in order to grow past these hard boundaries.
The peaceful Archaeocyatha lived during the most recent part of the Cambrian period. They separated into many families and were the Earth’s first reef-building animals.
Jorge and I packed up the night we arrived in Panama with Aaron O'Dea and his team from STRI . The road we took in two field vehicles mostly followed the Panama Canal heading northwards; we had to...
Rudist clams are mollusks that went extinct about 65 million years ago. They were the reef builders of the Cretaceous Period, the heyday of the dinosaurs. Today corals have taken over the role...
Whales swim, but their ancestors walked. Whales are mammals (like us) whose ancestors lived on land. Life probably began in the ocean and then evolved to colonize the land. Yet the whale’s ancestors...
Monodontids, the group of whales that includes the belugas and narwhals swimming our ocean today, are emblematic symbols of the Arctic. However, their fossil record, although scarce, suggests that...
The whales that we see in today's world can broadly be split into two groups: those with teeth (odontocetes), and those that have baleen (mysticetes) instead of teeth. These two groups share a common...
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...
Long before great white sharks appeared, much larger ancestors roamed the ocean. This giant ancient shark -- the Giant Megatooth ( Carcharodon megalodon ) -- was probably big enough to eat a whale.
Editor's note: Read Nick's first blog post about "toothed" baleen whales to see what their team is excavating on Vancouver Island. We departed from Port Renfrew on Tuesday morning on the Michelle...
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...
The foot-long extinct shark Falcatus falcatus lived during the early Carboniferous period around 325 million years ago. The species, known from fossils in the Bear Gulch formation of Montana , was...
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...
About 100 million years ago , during the heyday of the dinosaurs, reefs were built by mollusks called rudist clams. Like modern clams, rudists were bivalves , with two shells (or valves) joined at a...
400 to 1,000 year old bones from an endangered seabird, the Hawaiian petrel. Bones such as these provide a window into the lives of seabirds before and after human arrival in the open ocean...
Not all fossils from the Cambrian period became amulets; instead the extinct Hallucigenia sparsa was notable for its spines.
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