Algae = single cell plant living in water.

Allodesmus = Large sea lion that lived 15 million years ago.

Carnivore = Meat eater.

Cenozoic Era = The Age of Mammals from 65 million years ago to the present.

Desmostylus = a large extinct sea mammal with four legs that grazed on near shore sea grasses and mollusks.

Diatomite = Layered chalky-white rock made from microscopic plant shells.

Dire Wolf = A large Ice Age wolf with very strong jaws.

Extinct = No longer living.

Fossil = the remains of ancient life (footprints, trails, and burrows; insects trapped in amber; mineral-preserved bones, teeth, shells, and wood; carbon imprints).

Ginkgo = A prehistoric tree with fan shaped leaves from the Age of Dinosaurs that lives today in the parkl and around the City of Laguna Hills Community Center and Sports Complex.

Geologic Formation = A rock unit that is the same composition and formed in an ancient environment.

Geologic Time Scale = Geologic Time is arranged by major changes and events in climate, life forms, and crustal dynamics - the oldest time or event at the bottom and most recent at the top.

Ground Sloth = Ice Age bear-size mammal that used its curved front claws to pull down leaves and branches to eat.

Herbivore = A plant eater.

Ice Age = A term used to describe the geologic time when glaciers advanced and retreated over the polar and northern regions of the Earth.

Imagotarian = A large tuskless walrus that lived in the Laguna Hills deep sea over 12 million years ago.

Limestone = A sedimentary rock made from the calcium of ancient shells, coral, and algae.

Living Fossil = A plant or animal living today that has not changed for thousands or millions of years.

Mammoth = A large elephant-like mammal that was 13 feet high at its shoulders, had long curving tusks, and a high hump on its head. These Ice Age animals grazed as herds in grasslands. The mammoth found in Laguna Hills was the Columbian Mammoth.

Marine = A plant or animal that lives in the sea.

Mastodont = A primitive elephant-like mammal that had a solitary life in woodlands and wetlands. It had short tusks and was 8 feet tall at its shoulders.

Megalodon = Great white shark.

Mesozoic Era = Age of Dinosaurs 250 million years ago to 65 million years ago there are no Mesozoic rocks in the Laguna Hills.

Mysticeti = Whales with baleen sieve plates for teeth to strain out their food.

Odontoceti = Whales with sharp teeth this includes dolphins.

Paleontologist = A person who collects, cleans, identifies and catalogs fossil life.

Paleontology = the study of ancient life.

Paleozoic Era = Age of Early Life 540 millions years to 240 million years ago. There are no Paleozoic or older rocks in the Laguna Hills.

Pecten = Fan-shaped scallop shells.

Petrify = To turn to stone; replace molecules in a life form with minerals.

Predator = an animal that hunts and captures its food.

Prehistoric = Life forms and events that occurrred more than 10,000 years ago.

Preservation = To keep the shape and details of a life form.

Prey = Animals that graze on grass or browse on plants and are killed by predators.

Prong Horn Antelope = Ice Age deer-like animal with two Y shaped horns. Became extinct in the Santa Ana Mountains 100 years ago.

Reef = an undersea mound or ridge built by coral, sea shells, or other calcareous animals and plants.

Saber-toothed Cat = California State Fossil that lived during the Ice Age.

Saddleback Valley = A valley in southern Orange County, California, that extends from the Santa Ana Mountains westward to the Laguna Hills. It was a bay in ancient times.

Sandstone = rock made from sand cemented and compressed together.

Savannah = Grasslands with scattered trees.

Shale = A sedimentary rock that is layered silt or mud - usually deposited in water.

Teratorn Vulture = A large "Ice Age" scavenger bird similar to the giant condor. Its wing span was 12 feet.

Terrestrial = A plant or animal that lives on land.

Tusk = long pointed canine tooth - curved on mammoths, mastodonts, and elephants - straight on walrus.

Walrus = Large marine mammal related to seals. Having two flippers, two long tusks, and coarse whiskers. Walrus eat shell-fish and live near shore.

Whale = Large marine mammals that live in the open sea and include killer whales, baleen whales, porpoises, and dolphins. They have fins and a flat tail fluke.