in large amounts.

(1700s) period in European history where science and reason were promoted as ideals of good citizens and society.

(singular: alga) diverse group of aquatic organisms, the largest of which are seaweeds.

translucent, yellow-orange material made of the resin of ancient trees. Amber is sometimes considered a gemstone.

organisms that have a well-defined shape and limited growth, can move voluntarily, acquire food and digest it internally, and can respond rapidly to stimuli.

part of something that extends out from the main body, such as an arm or leg.

having to do with water.

extinct reptilian bird that lived about 150 million years ago.

invertebrate animal with a segmented body, exoskeleton, and jointed appendages.

view or interpretation.

alterations in the layer of air surrounding the Earth, such as an increase of pollution or humidity.

the basic unit of an element, composed of three major parts: electrons, protons, and neutrons.

(singular: bacterium) single-celled organisms found in every ecosystem on Earth.

having to do with the Bible, the holy book of Christianity.

scientist who studies living organisms.

study of the dating of rock layers.

disaster or sudden, violent change.

smallest working part of a living organism.

(1809-1882) British naturalist.

(1797-1875) English geologist.

study of the atoms and molecules that make up different substances.

complex way of life that developed as humans began to develop urban settlements.

to identify or arrange by specific type or characteristic.

all weather conditions for a given location over a period of time.

gradual changes in all the interconnected weather elements on our planet.

dark, solid fossil fuel mined from the earth.

spherical structure of fossilized plant matter found in and around coal deposits.

a coworker or partner.

material that surrounds or links different organs or other parts of an organism.

one of the seven main land masses on Earth.

tiny ocean animal, some of which secrete calcium carbonate to form reefs.

rocky outermost layer of Earth or other planet.

type of animal (an arthropod) with a hard shell and segmented body that usually lives in the water.

(computerized tomography scanner) device combining X-ray and computerized equipment to provide cross-sectional images of internal body structures. Also called a CAT scanner.

able to cure or treat a disease or illness.

type of aquatic bacteria that can photosynthesize light to create energy. Also called blue-green algae (even though it is not algae) and (in freshwater habitats) pond scum.

(singular: datum) information collected during a scientific study.

remains of something broken or destroyed; waste, or garbage.

to decay or break down.

to reach a conclusion based on clues or evidence.

area of land that receives no more than 25 centimeters (10 inches) of precipitation a year.

place where paleontologists, archaeologists, or other scientists are digging into the Earth to find artifacts or fossils. Also called an excavation.

to prove wrong.

difference.

(deoxyribonucleic acid) molecule in every living organism that contains specific genetic information on that organism.

phylum of marine invertebrate including sea stars and sea urchins.

community and interactions of living and nonliving things in an area.

powerful device that uses electrons, not light, to magnify an image.

chemical that cannot be separated into simpler substances.

an adventurer, scientist, innovator, or storyteller recognized by National Geographic for their visionary work while still early in their careers.

to give off or send out.

conditions that surround and influence an organism or community.

to form or officially organize.

change in heritable traits of a population over time.

to develop new characteristics based on adaptation and natural selection.

area that has been dug up or exposed for study.

the hard external shell or covering of some animals.

no longer existing.

scientific studies done outside of a lab, classroom, or office.

large, flat limb used by marine mammals for swimming.

ecosystem filled with trees and underbrush.

to develop or create.

remnant, impression, or trace of an ancient organism.

coal, oil, or natural gas. Fossil fuels formed from the remains of ancient plants and animals.

(singular: fungus) organisms that survive by decomposing and absorbing nutrients in organic material such as soil or dead organisms.

having to do with genes, inherited characteristics or heredity.

extinct large, flightless bird indigenous to Australia.

person who studies the physical formations of the Earth.

(1769-1832) French paleontologist and biologist.

mass of ice that moves slowly over land.

large desert in China and Mongolia.

duck-billed dinosaur.

group of animals.

statement or suggestion that explains certain questions about certain facts. A hypothesis is tested to determine if it is accurate.

long period of cold climate where glaciers cover large parts of the Earth. The last ice age peaked about 20,000 years ago. Also called glacial age.

sign or signal.

animal without a spine.

study of the fossils of animals without spines, such as corals, sponges, and insects.

to set one thing or organism apart from others.

organ in an animal that is necessary for breathing.

animal with hair that gives birth to live offspring. Female mammals produce milk to feed their offspring.

one of many extinct species of large animals related to elephants, with long, curved tusks. The last mammoths became extinct about 5,000 years ago.

having to do with the ocean.

fossil that can only be seen and analyzed with a microscope, such as a grain of pollen or a single bacterium.

very tiny living thing.

study of fossils of microorganisms.

(500-1500) period in European history between the Roman Empire and the Renaissance.

type of fungi that forms on the surface of materials.

large phylum of invertebrate animal, all possessing a mantle with a significant cavity used for breathing and excretion, a radula (except for bivalves), and the structure of the nervous system. 

legend or traditional story.

(1888) organization whose mission is "Inspiring people to care about the planet."

protected area built by birds to hatch their eggs and raise their young.

story in the Bible, a catastrophe that eliminated almost all life on Earth.

substance an organism needs for energy, growth, and life.

type of marine animal (mollusk).

study of the fossils of ancient plants.

study of the atmosphere of prehistoric Earth.

study of prehistoric environments and habitats.

person who studies fossils and life from early geologic periods.

the study of fossils and life from early geologic periods.

large plateau in southern South America, stretching from the Andes Mountains to the Atlantic Ocean.

to turn to stone.

person who is among the first to do something.

organism that produces its own food through photosynthesis and whose cells have walls.

powdery material produced by plants, each grain of which contains a male gamete capable of fertilizing a female ovule.

period of time that occurred before the invention of written records.

before or ahead of.

type of microscopic organism (not an animal, plant, or fungus). 

extinct order of flying reptiles that flourished from 220 million-65 million years ago.

flying reptile that lived about 70 million years ago, native to North America.

having unstable atomic nuclei and emitting subatomic particles and radiation.

method of dating material such as rocks that compares the amount of a naturally occuring isotope of an atom and its decay rates. Also called radioactive dating.

clear, sticky substance produced by some plants.

to completely change a process or way of doing something.

part of a plant that secures it in the soil, obtains water and nutrients, and often stores food made by leaves.

educated person.

surface layer of the bottom of the ocean.

solid material transported and deposited by water, ice, and wind.

to put in order.

(1031-1095) Chinese scientist, politician, and poet.

region of land stretching across Russia from the Ural Mountains to the Pacific Ocean.

bones of a body.

connective tissue of an organism, such as blood, muscle, and skin.

individual organism that is a typical example of its classification.

simple type of marine animal permanently attached to something in the water.

fossil of ancient cyanobacteria that forms a rounded or column-like structure.

field of study within a larger area of research.

to be unable to breathe.

to support.

land permanently saturated with water and sometimes covered with it.

the science of using tools and complex machines to make human life easier or more profitable.

type of dinosaur that walked on two legs and was usually carnivorous.

(Tyrannosaurus rex) large carnivorous or scavenger dinosaur.

to dig up.

organism with a backbone or spine.

study of the fossils of animals with spines, such as dinosaurs.

activity that includes a discharge of gas, ash, or lava from a volcano.

(1769-1839) English geologist.

the distance between the tips of a bird's wings when stretched out.

animal with a long, limbless body.

(570-480 BCE) Greek philosopher and poet.