apex predator: An animal at the top of the food chain. Such predators also have no predators themselves.
biogeochemist: Someone who studies processes that cycle (or eventually deposit) pure elements or chemical compounds (including minerals) between living species and nonliving aspects (such as rock or soil or water) of an ecosystem. This field of study is known as biogeochemistry.
bond: (in chemistry) A semi-permanent attachment between atoms — or groups of atoms — in a molecule. It’s formed by an attractive force between the participating atoms. Once bonded, the atoms will work as a unit. To separate the component atoms, energy must be supplied to the molecule as heat or some other type of radiation.
carbon: A chemical element that is the physical basis of all life on Earth. Carbon exists freely as graphite and diamond. It is an important part of coal, limestone and petroleum, and is capable of self-bonding, chemically, to form an enormous number of chemically, biologically and commercially important molecules.
carnivore: An animal that either exclusively or primarily eats other animals.
chemical reaction: A process that involves the rearrangement of the molecules or structure of a substance, as opposed to a change in physical form (as from a solid to a gas).
chemistry: Chemistry often is used as a term to refer to the recipe of a compound, the way it’s produced or some of its properties. People who work in this field are known as chemists.
climate: The weather conditions that typically exist in one area, in general, or over a long period.
climate change: Long-term, significant change in the climate of Earth. It can happen naturally or in response to human activities, including the burning of fossil fuels and clearing of forests.
cold-blooded: Adjective for an animal whose body temperature varies with that of its environment.
ecosystem: A group of interacting living organisms — including microorganisms, plants and animals — and their physical environment within a particular climate. Examples include tropical reefs, rainforests, alpine meadows and polar tundra. The term can also be applied to elements that make up some an artificial environment, such as a company, classroom or the internet.
element: (in chemistry) Each of more than one hundred substances for which the smallest unit of each is a single atom. Examples include hydrogen, oxygen, carbon, lithium and uranium.
enamel: The glossy, hard substance that covers a tooth.
epoch: (in geology) A span of time in the geologic past that was shorter than a period (which is itself, part of some era) and marked when some dramatic changes occurred.
evolutionary: An adjective that refers to changes that occur within a species over time as it adapts to its environment. Such evolutionary changes usually reflect genetic variation and natural selection, which leave a new type of organism better suited for its environment than its ancestors. The newer type is not necessarily more “advanced,” just better adapted to the conditions in which it developed.
extinct: An adjective that describes a species for which there are no living members. Extinction refers to the permanent loss of a species, family or larger group of organisms.
fossil: Any preserved remains or traces of ancient life. There are many different types of fossils: The bones and other body parts of dinosaurs are called “body fossils.” Things like footprints are called “trace fossils.” Even specimens of dinosaur poop are fossils. The process of forming fossils is called fossilization.
isotopes: Different forms of an element that vary somewhat in mass (and potentially in lifetime). All have the same number of protons in their nucleus, but different numbers of neutrons.
kin: Family or relatives (sometimes even distant ones).
marine mammal: Any of many types of mammals that spend most of its life in the ocean environment. These include whales and dolphins, walruses and sea lions, seals and sea otters, manatees and dugongs — even polar bears.
megalodon: An extinct shark species, Otodus megalodon, that lived between the early Miocene (an epoch which started some 23 million years ago) and the end of the Pliocene (roughly 2.6 million years ago). Most scientists believe it was the largest fish to ever live. Its name comes from the Greek and means gigantic tooth. The average adult member of this species could have spanned more than 10 meters (33 feet) and weighed 30 metric tons (66,000 pounds) or more.
metabolism: (adj. metabolic) The set of life-sustaining chemical reactions that take place inside cells and bigger structures, such as organs. These reactions enable organisms to grow, reproduce, move and otherwise respond to their environments.
mollusks: Soft-bodied invertebrate animals that usually live in water and develop a hard protective shell. Examples include snails, shellfish (like clams and oysters), slugs, octopuses and squids.
oxygen: A gas that makes up about 21 percent of Earth’s atmosphere. All animals and many microorganisms need oxygen to fuel their growth (and metabolism).
paleobiologist: A scientist who studies organisms that lived in ancient times — especially geologically ancient periods, such as the dinosaur era.
predator: (adjective: predatory) A creature that preys on other animals for most or all of its food.
prey: (n.) Animal species eaten by others. (v.) To attack and eat another species.
Proceedings of the National Academy of Sciences: A prestigious journal publishing original scientific research, begun in 1914. The journal’s content spans the biological, physical and social sciences. Each of the more than 3,000 papers it publishes each year, now, are not only peer reviewed but also approved by a member of the U.S. National Academy of Sciences.
seawater: The salty water found in oceans.
shark: A type of predatory fish that has survived in one form or another for hundreds of millions of years. Cartilage, not bone, gives its body structure. Like skates and rays, sharks belong to a group known as elasmobranchs. They tend to grow and mature slowly and have few young. Some lay eggs, others give birth to live young.
trait: A characteristic feature of something.
Wales: One of the three components of Great Britain (the other two being England and Scotland. It’s also part of the United Kingdom (whose other members include England, Scotland and Northern Ireland).
warm-blooded: Adjective for animals (chiefly mammals and birds) that maintain a constant body temperature, typically above that of their surroundings. Scientists generally prefer the term endothermic to describe animals that generate heat to control their body’s temperature.
whale: A common, but fairly imprecise, term for a class of large mammals that lives in the ocean. This group includes dolphins and porpoises.