More Geologic time

The Ocean Blog

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...
Hantkenina mexicana -- a foram with elongated shell chambers that lived between 45-49 million years ago, during the Eocene Epoch. This specimen is from marine sediments that were drilled in the...
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...
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...
These are fossil remains of archaeocetes, ancient whales, from the Paracas Formation of Peru's Pisco Basin . Smithsonian paleobiologist Nicholas D. Pyenson and a team of scientists discovered the...
This specimen of the deep-sea coral Desmophyllum dianthus shows the visible bands that help marine scientists learn how ocean conditions changed over time. By looking at the thickness of each band,...
When the cod fishery collapsed in Newfoundland in the early 1990s, the hopes of the local fish harvesters collapsed with it. Hundreds of Newfoundlanders moved away and businesses that depended on the...
Building the Smithsonian's Sant Ocean Hall --like any major exhibition--was a major undertaking. Over the course of five years, it required hundreds of people with a vast array of skills and...
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 ,...
Earth’s first animals had soft bodies. This illustration shows a community of soft-bodied Ediacaran (edi-A-karan) animals. Some species resemble living ocean creatures. Others are unlike any known...
What makes a top predator? Razor-sharp teeth? Speed? Strength? Size? Who is the most fearsome hunter? It depends on where and when you look.
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...
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—...
About 100 million years ago, during the heyday of the dinosaurs , reefs were built by mollusks called rudist clams . They looked very different from today's coral reefs . Discover more about the...
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...
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...
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...
The evolution of whales represents one of the great stories in macroevolution. It's a narrative that has mostly benefitted from an extraordinary series of fossils recovered from rocks around the...
Subscribe to Geologic time