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Cretaceous: Earth Processes  K-T: Extinction  Eocene: Evolution
Oligocene: Evolution  |  Miocene: Earth Processes  |  Pliocene: Paleocology
Pleistocene: Extinction


Exhibit Map: Cretaceous: Earth Processes

Look at fossil clues to discover the dinosaurs of our region, where they lived, and why their fossils are rare here.

75 million years ago, dinosaurs ambled over steep mountains, which plunged into the warm Pacific Ocean. The fossils in this section are from Southern California and Baja California during the Cretaceous (kreh TAY shus) Period.

What You Can See

Big and ferocious, Albertosaurus lunges toward the crested Lambeosaurus defending her nest. Ankylosaur watches with anticipation. Dive beneath the waves and find an unexpected dinosaur. Resting in peace, its bones form a reef of oysters and clams. Ammonites with large coiled shells swim by, while mosasaurs and sharks lurk in the shadows.

What You Can Do

  • Meet our rare regional dinosaurs in the flesh-Albertosaurus and Lambeosaurus. Then walk around to the other side to see their complete skeletons.
  • Make a baby dinosaur emerge from its egg. Ponder which came first, the dinosaur or the egg?
  • Touch a life-size model of an armored ankylosaur from coastal San Diego County.
  • Solve the mystery how this dinosaur lived on land, became a fossil at sea, and was discovered on land.
  • Arrange pictures to create stories about Earth changes, prehistoric life, and the formation of fossils. Watch your stories play on a big screen.
  • Find the dinosaur fossils on a model of the Cretaceous environment. See how the landscape then compares with today. 75 million years ago, steep coastal mountains plunged into the Pacific Ocean.
  • Look at the beautiful abundance of fossil marine invertebrates: ammonites, nautilus, tropical snails, sea stars, and more.
  • Discover how these fossils help us understand past environments.
  • Fossils are relevant.

Fossils show that environments change-what we see today is not how it has always been. What does that tell us about the future?

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Exhibit Map: K-T Extinction

Fossil clues from around the world show that after the mass extinction 65 million years ago, new life forms evolved to take advantage of new opportunities.

What You Can See and Do

Stand on the threshold of the age of dinosaurs and the age of mammals. Bathed in red light, a dead feathered dinosaur is consumed by small mammal survivors. See a chunk of Earth that records events following a meteor impact, when dinosaurs became extinct and the world changed forever.

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Exhibit Map: Eocene: Evolution

Compare fossil clues to modern animals to see how form and function relate. Imagine prehistoric looks, lifestyles, and locomotion.

34 to 55 million years ago, unfamiliar forms of mammals lived in subtropical woodlands bordered by lagoons. The fossils in this section are from San Diego County during the Eocene (EE oh seen) Epoch.

What You Can See

Enter a lush subtropical woodland bursting with unusual plants and animals. Sights, sounds, and smells activate your senses. Primates leap through avocado trees, rhinoceros-like brontotheres crash through dense foliage, crocodiles prowl around a lily-filled lagoon. Thunder rolls-a storm threatens. Birds sing while bats sleep in tree hollows.

What You Can Do

  • Find and identify plants and animals in the woodlands and lagoons of prehistoric San Diego County. See how scientists and artists use life in the present to interpret the fossil evidence to recreate a 45-million-year-old habitat.
  • Sift for tiny fossils. Look at them through a microscope and determine their identity.
  • Like a paleontologist, compare fossils to modern bones and discover how prehistoric animals lived. What did they eat? How did they move? Examine the fossil clues!
  • Look at fossil plants and figure out the conditions of prehistoric climates.
  • Learn about the evolution of mammal diversity, made possible by the extinction of dinosaurs.

Fossils are relevant. Discovering the relationship between form and function (how bones are shaped and how they move) helps us to understand how life works. How can we apply this knowledge to solve challenges today?


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Exhibit Map: Oligocene: Evolution

Compare fossil clues with modern animals to discover how form and function relate, and how animals' bodies adapt to challenges and opportunities in their environment.

24 to 34 million years ago, the climate dried and cooled, forests receded, grasslands expanded, and runners burst onto the scene. Fossils in this section are from San Diego County during the Oligocene (AH lig oh seen) Epoch.

What You Can See

Herds of grazing animals-camels, mouse deer, and oreodonts-extend as far as the eye can see. Forerunners of modern cats and dogs look on with hunger, as one breaks into a chase. A tortoise, protected by a domed shell, lazily nibbles flowers. Volcanoes smoke in the distance.

What You Can Do

  • Look at fossil skulls and skeletons and discover prehistoric animals' unique survival strategies.
  • Operate jaws and teeth of predators and prey. Which teeth are good for shearing and slicing meat? Which are better for grinding leaves?
  • Examine fossil fragments and learn how to identify their lifestyle and diet.
  • Move models of animal bones to discover how form and function relate. Learn to tell the difference between a runner, a climber, and a swimmer.
  • Test your ability to move like an animal. Can you run like a deer, climb like a monkey, and swim like a sea lion?

Fossils are relevant. We share the world with animals with tremendous capabilities. Fossils help us understand how they evolved their wonderful traits, nurturing our wonder for life.

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Exhibit Map: Miocene: Earth Processes

Look at fossil clues and rocks to discover how plate tectonics-Earth's moving crust-sculpts our geography.

5 to 24 million years ago, Earth's moving plates ripped a peninsula from the North American mainland, a gulf filled with water, and prehistoric seafloors were lifted high and dry. The fossils in this section are from Southern California and Baja California during the Miocene (MY oh seen) Epoch.

What You Can See

See how moving plates of our planet's crust have shaped the Earth-past and present. Various views of our dynamic planet illustrate the profound effects of plate movement, from the shape of continents to the profile of mountains. When fossils from past oceans are found in our region's deserts and mountains today, these fossil mysteries can only be understood in light of plate tectonics. Encounter one of these fossil mysteries-the 40-foot Carcharodon megalodon- the largest predatory shark of all time.

What You Can Do

  • Make a big map move. Millions of years pass in minutes and Peninsular California rips from North America on an interactive map.
  • Operate a computer model showing plate tectonics in the past and the movement of Earth's plates over millions of years. Go forward and backward in time to see the changing configuration of oceans and continents.
  • Operate a computer model showing plate tectonics in the present. See the distribution of volcanoes and earthquakes and notice they delineate the plate boundaries.
  • Move models that illustrate how plates interact when they collide, spread apart, and slide side-by-side.
  • Look at and touch rocks and fossils and explore the mysteries of our changing landscape. Why are fossil corals, sponges, seashells, and shark teeth found in our local desert? Discover the link between plate tectonics and life.

Fossils and rocks are relevant. Rocks and fossils reveal the effects of plate movement which we feel as earthquakes. How can understanding geologic forces and the location of faults help us prepare for future earthquakes and other geologic events?

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Exhibit Map: Pliocene: Paleocology

Look at fossil clues to discover prehistoric ecology-the roles and relationships in this 3 million-year-old ocean community.

1.8 to 5 million years ago, a great diversity of animals swam a giant bay, which stretched from La Jolla through downtown San Diego to south of Tijuana. These fossils are from Southern California and Baja California during the Pliocene (PLY oh seen) Epoch.

What You Can See

A giant sea cow mama and baby float peacefully in a kelp forest. Sea birds dive and nab silvery fish swirling in an energetic ball. Walruses swim upside-down feeling the bay bottom with their bristly whiskers. Sharks circle a diversity of whales. Sand dollars, scallops, clams, and snails live, die, and become fossils in an expansive bay.

What You Can Do

  • Marvel at the size and shape of our fossil whales. How do their skulls reveal their diets?
  • Look at the variety of fish and bird fossils. Which ones still live here today?
  • Compare several fossil walrus skulls. How did they use their teeth and tusks? Why are they so different?
  • View a half skeleton/half modeled 30-foot sea cow and discover the ecological role of this giant extinct herbivore. Climb on the back of a baby sea cow and learn what it means to be a marine mammal.
  • Examine marine invertebrate fossils -from big to microscopic-that help us map the Pliocene bay.
  • Watch video of modern animals moving in their habitat and imagine life in this prehistoric bay.

Fossils are relevant. Living communities were bound by relationships in the past as they are in the present. Might we better understand present ecosystems by studying past ecosystems?

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Exhibit Map: Pleistocene: Extinction

Look at fossil clues to discover the pattern of extinction, possible causes, and links to the present.

10,000 to 1.8 million years ago, animals both giant and familiar lived amid dramatic climate swings and changing sea levels. The fossils in this section are from Southern California and Baja California during the Pleistocene (PLYS toh seen) Epoch.

What You Can See

A mastodon faces down a giant lion, while a baby mastodon runs for safety. An enormous ground sloth tears into an agave; horses and camels graze. Condors tend a nest. Tapirs and capybaras splash in the lake while saber-tooth cats and dire wolves wait for opportunity.

What You Can Do

  • Look at fossils skeletons of mastodon, sabertooth cat, dire wolf, and giant ground sloth. Ponder the mystery of their extinction.
  • Look through magnifiers at tiny fossils and compare them to modern mammal skulls and teeth. Discover why small mammals survived in much greater numbers.
  • Crawl into an Ice Age lion's cave. What kinds of fossil clues do you find there?
  • Move the jaws of a sabertooth cat and learn why, despite their amazing adapations, they could not survive.
  • Make a mural scene change. See how large mammals flourished in our region, climate and habitats changed, and people migrated in to North America. Explore the controversial mystery why the megafauna became extinct 10,000 years ago while small animals survived.
  • Kangaroo rat, pond turtle, night heron-all are Ice Age survivors. Look around the gallery. How many more can you find?

Fossils are relevant. We live in a time of massive extinction. Might the Pleistocene extinction help us to understand present and future extinction?

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  • Geologic Timeline