Glossary

Arthropod: A phylum of animals which possess jointed limbs and exoskeletons made of a material called chitin. Insects, beetles, arachnids, crustaceans, centipedes, and many other creepy-crawlies are all arthropods. 

Cell: The smallest, most basic unit of life, a cell is a self-contained and self-replicating unit. Large organisms are made of many cells (they are multicellular), while many microscopically-small organisms consist of only a single cell (called unicellular). Cells have a clear border, contain DNA, can make more copies of themselves, and can perform functions vital to their continued existence. 

Crepuscular: An animal which is primarily active at dawn and dusk. 

Diurnal: An animal which is primarily active during the day.

Ecosystem: A distinct, interconnected community of many species as well as the environment those species live in. Organisms in an ecosystem exchange energy (through, y’know, eating each other) and compete for resources. A species typically serves a certain role within its ecosystem, known as a niche. 

Electroreception: The ability of an organism, usually an animal, to detect electromagnetic fields produced by other animals. This allows animals to search for prey in conditions where sight or smell are not useful or when prey is camouflaged. Many kinds of vertebrates can use electroreception, such as catfish, elephantfish, sharks, and a few mammals such as the platypus and echidna. 

Endangered: A distinction specifying that an animal has a high risk of going extinct in the future. 

Extinct: A distinction given to a species that no longer exists— all of its members have died. Just about 99% of species that have existed have gone extinct. A species can go extinct for a variety of reasons, from climate change to cataclysmic disasters like the asteroid that killed the dinosaurs. Nowadays, many species go extinct due to human activity. 

Genus: The second-narrowest taxonomic group, a genus is a collection of many related species. The first word in a scientific name (Ex: Homo sapiens) refers to the genus. \

Invertebrate: An animal that does not have a spinal cord or an internal skeleton. The overwhelming majority of animals on Earth are invertebrates: jellyfish, corals, molluscs, insects, beetles, worms, crustaceans, sponges, starfish, etc. 

IUCN: International Union for the Conservation of Nature. The IUCN is the largest and most respected conservation institution in the world. They are most famous for their IUCN Red List, which is the most trusted ledger of species endangerment in the world. Generally, if you hear that a species is endangered, that distinction was bestowed upon them by the IUCN. 

Organism: A single individual living thing, be it a plant, animal, fungus, bacteria, or otherwise. It is sometimes used to refer to a type of living thing as a synonym for species. 

Oviparous: An animal that lays eggs containing its offspring, like a chicken. 

Scientific Name: A two-part naming scheme used in biology to distinguish a particular species of organism from other, similar species. While two organisms may have the same common name, no two organisms have the same scientific name (usually). The scientific name is generally written in a dead language, such as Latin or ancient Greek, and is italicized. 

Ex: Homo sapiens (human), Drosophila melanogaster (fruit fly), Gorilla gorilla (Western Lowland Gorilla- no seriously this is the scientific name for the Western Lowland Gorilla). 

Species: The narrowest taxonomic group, a species is a single type of organism, usually delineated by unique traits compared to other similar organisms and an inability to breed and produce fertile offspring with organisms of a different species. Despite how ironclad it sounds, exactly what constitutes a species is a topic of hot debate in biology. The second word in a scientific name (Ex: Homo sapiens) refers to the species. 

Tetrapod: Literally meaning “four-footed”, tetrapods are a type of vertebrate which has four limbs. All land-dwelling vertebrates: amphibians, birds, reptiles, and mammals, are tetrapods. 

​

Vertebrate: An animal that possesses a spinal cord and an internal skeleton. You are a vertebrate (unless you’re that one reader who’s a dung beetle— weirdo). 

Viviparous: An animal that gives birth to live young, like a human.