You’ve probably noticed that a lot of dinosaur names end in the suffix -saurus. Some others you might know end in -ceratops or -raptor. But can you guess what sort of dinosaur (or other creature) it might be, just based on the name? Often, yes–and here I’ll show you how!

Dinosaurs

-saurus: Greek for “lizard”. Usually used as a general-purpose ending for dinosaurs. Examples: Spinosaurus (spine lizard), Stegosaurus (roof lizard), Tyrannosaurus (tyrant lizard). Counterexamples: Lystrosaurus (shovel lizard) is actually a stem-mammal; Mastodonsaurus (breast tooth lizard) is actually a stem-amphibian; Arizonasaurus (Arizona lizard) is actually a stem-crocodylian. More often than not though, -saurus indicates dinosaur.

-raptor: Latin for “thief”. Usually used for theropod dinosaurs in the Pennaraptor family, including Dromaeosaurs and Oviraptorosaurs. If it has this suffix, it’s probably bipedal, carnivorous or omnivorous, small (for a dinosaur), fast-moving, and feathered. Examples: Velociraptor (swift thief), Utahraptor (Utah thief), Microraptor (small thief), Oviraptor (egg thief). Counterexample: Eoraptor (dawn thief) is actually a sauropodomorph.

-ceratops: This is actually two suffixes stuck together, “cerat,” Greek for “horn,” and “ops,” Greek for “face”. Usually used for ornithischian dinosaurs in the ceratopsian family. If it has this suffix, it’s probably quadrupedal, definitely herbivorous, and has a bony frill, a beak, and probably horns on its face. Examples: Triceratops (three horned face), Protoceratops (first horned face), Kosmoceratops (ornate horned face). Counterexample: Tetraceratops (four horned face) is actually a stem-mammal.

-mimus: Greek for “mimic”. Usually used for theropod dinosaurs in the Ornithomimid family. If it has this suffix, it’s probably bipedal, feathered, herbivorous or omnivorous, with long legs and a long neck. Examples: Struthiomimus (ostrich mimic), Gallimimus (chicken mimic), Pelecanimimus (pelican mimic). Counterexample: Suchomimus (crocodile mimic) is actually a spinosaurid.

-titan: Greek for, well, “titan”. Usually used for sauropods in the Titanosaur family. If it has this suffix, it’s probably huge, quadrupedal, herbivorous, with a long neck and vertical posture. Examples: Giraffatitan (giraffe titan), Patagotitan (titan from Patagonia), Dongbeititan (titan from Dongbei). Counterexamples: Aerotitan (air titan) is an azhdarchid pterosaur (giant flying reptile); Tyrannotitan (tyrant titan) is a carcharodontosaurian theropod (large carnivorous dinosaur); Olorotitan (swan titan) is a large ornithopod (duck-billed dinosaur).

-pelta: Greek for “shield”. Usually used for ankylosaurs (armored dinosaurs). If it has this suffix, it’s probably quadrupedal, herbivorous, and heavily armored. Examples: Borealopelta (northern shield), Europelta (European shield), Crichtonpelta (Michael Chrichton’s shield).

-pteryx: Greek for “feather”. Usually used for paravian dinosaurs (non-birds closely related to birds). If it has this suffix, it’s probably bipedal, feathered, and can maybe fly a little bit. Examples: Archaeopteryx (ancient feather), Scansoriopteryx (climbing feather), Epidexipteryx (display feather). Counterexamples: Sinosauropteryx (Chinese lizard feather) is a flightless compsognathid theropod; Sharovipteryx (Sharov’s feather) is a reptile with leg-wings (!) from the Middle Triassic.

-venator: Latin for “hunter”. Usually used for carnivorous theropods of various kinds. If it has this suffix, it’s probably bipedal, carnivorous, and fast-moving. Examples: Neovenator (new hunter), Ichthyovenator (fish hunter), Skorpiovenator (scorpion hunter), Australovenator (southern hunter), Latenivenatrix (hiding huntress).

-long: Mandarin for “dragon”. Usually used as a general-purpose ending for dinosaurs discovered in China. Examples: Yinlong (hidden dragon), Guanlong (crown dragon), Beibeilong (baby dragon).

Mammals

-therium: Greek for “beast”. Usually used for large mammals. If it has this suffix, it’s probably large, quadrupedal, and herbivorous. Examples: Paraceratherium (near hornless beast), Megatherium (large beast), Arctotherium (bear beast), Chalicotherium (gravel beast).

-cyon: Greek for “dog”. Usually used for canids and their close relatives. If it has this suffix, it’s probably very dog-like. Examples: Hesperocyon (western dog), Epicyon (more than dog), Archaeocyon (ancient dog), Hemicyon (half dog).

-pithecus: Greek for “ape”. Usually used for…apes. Yes. Examples: Australopithecus (southern ape), Gigantopithecus (giant ape), Dinopithecus (terrible ape).

-cetus: Greek for “whale”. Usually used for stem-whales. If it has this suffix, it’s probably semiaquatic or fully aquatic, carnivorous, and maybe kind of scary-looking. Examples: Ambulocetus (walking whale), Pakicetus (Pakistan whale), Maiacetus (mother whale).

Others

-erpeton: Greek for “creeper”. Usually used for temnospondyl amphibians. If it has this suffix, it’s slimy, usually quadrupedal, aquatic or semiaquatic, and large for an amphibian. Examples: Dendrerpeton (tree creeper), Tulerpeton (creeper from Tula), Ophiderpeton (snake creeper). Counterexample: Lagerpeton (rabbit creeper) is actually a dinosauromorph.

-suchus: Greek for “crocodile”. Usually used for pseudosuchians (crocodiles and their ancestral cousins). If it has this suffix, it’s probably scaly, quadrupedal, usually carnivorous, and has osteoderms or armor in its skin. Examples: Pakasuchus (cat crocodile), Postosuchus (crocodile from Post), Gracilisuchus (slender crocodile). Counterexamples: Procynosuchus (before dog crocodile) is actually a stem-mammal; Koolasuchus (Kool’s crocodile) is actually a temnospondyl amphibian.

Pter- or -pterus: Greek for “wing”. Usually used for pterosaurs (flying non-dinosaur reptiles). If it has this root, it probably flies on membranous wings supported by an elongated fourth finger and is covered in pycnofibres. Examples: Pterodactylus (winged finger), Pteranodon (winged toothless), Pterodaustro (winged south); Darwinopterus (Darwin’s wing), Noripterus (lake wing).

-ella: Latin diminutive (something you add to a name to make it cuter, like -ita in Spanish (Rosa > Rosita) or -ie in English (Kate > Katie)). Usually used for super-ancient primitive creatures from the Ediacaran and Cambrian periods (approx 610-485 mya). If it has this suffix, it’s probably slimy, simple, and aquatic. Examples: Kimberella, Aspidella, Cindarella (no kidding), Haikouella, Marrella. Counterexamples: Eohostimella is a plant; Perryella is a temnospondyl.