Dinosaur glossary
Terms that come up often on this site and in dinosaur books, explained briefly with links to read more.
Dinosaur groups
- DinosaurDinosauria
- A group of reptiles descended from one common ancestor, with legs held straight under the body. They appeared in the Triassic about 230 million years ago, and today's birds count as dinosaurs too.
- Read more on this site →Source: Wikipedia
- Non-avian dinosaurs
- All dinosaurs except birds. They all died out 66 million years ago, and they are what most people mean by "dinosaurs".
- Read more on this site →Source: Wikipedia
- Saurischia (lizard-hipped)Saurischia
- One of the two traditional main groups of dinosaurs, made up of theropods and sauropodomorphs. Some studies propose a different split, so this grouping is still debated.
- Source: Wikipedia
- Ornithischia (bird-hipped)Ornithischia
- A large group of plant-eating dinosaurs with an extra beak bone at the front of the lower jaw, such as Stegosaurus, Ankylosaurus, Triceratops and duck-billed dinosaurs. Despite the name, birds are not in this group.
- Source: Wikipedia
- TheropodTheropoda
- Two-legged dinosaurs, mostly meat-eaters, such as Tyrannosaurus, Velociraptor and Siamraptor. Today's birds descend from theropods.
- Source: Wikipedia
- SauropodomorphSauropodomorpha
- Long-necked plant-eating dinosaurs, from small early forms, some of them two-legged, to the giant sauropods.
- Source: Wikipedia
- SauropodSauropoda
- Four-legged plant-eating dinosaurs with very long necks and tails, including the largest land animals ever, such as Brachiosaurus and Thailand's Phuwiangosaurus.
- Read more on this site →Source: Wikipedia
- TitanosaurTitanosauria
- Sauropods that lasted to the end of the Cretaceous, including several of the biggest dinosaurs, such as Argentinosaurus and Patagotitan.
- Read more on this site →Source: Wikipedia
- CeratopsianCeratopsia
- Plant-eating dinosaurs with parrot-like beaks, many with frills and horns, such as Triceratops. Psittacosaurus, found in Thailand, belongs here too.
- Source: Wikipedia
- Ankylosaur (armored dinosaur)Ankylosauria
- Low, wide plant-eating dinosaurs whose backs were covered in bony armor plates; some had a bony club at the end of the tail.
- Source: Wikipedia
- Hadrosaur (duck-billed dinosaur)Hadrosauridae
- Late Cretaceous plant-eaters with broad, flat duck-like bills and hundreds of grinding teeth; some had head crests, such as Parasaurolophus.
- Source: Wikipedia
- ArchosaurArchosauria
- The larger reptile group that includes crocodiles, pterosaurs and dinosaurs (birds included), which is why crocodiles are the closest living relatives of dinosaurs after birds.
- Read more on this site →Source: Wikipedia
- PterosaurPterosauria
- Flying reptiles with skin wings stretched along the fourth finger: close relatives of dinosaurs, but not dinosaurs.
- Read more on this site →Source: Wikipedia
- PlesiosaurPlesiosauria
- Sea reptiles that swam with four flippers, many with very long necks; the short-necked, big-headed pliosaurs are a branch of the group. Not dinosaurs.
- Read more on this site →Source: Wikipedia
- IchthyosaurIchthyosauria
- Dolphin-shaped sea reptiles that gave birth to live young at sea: a separate branch of reptiles from the dinosaurs.
- Read more on this site →Source: Wikipedia
- MosasaurMosasauridae
- Giant sea lizards of the Late Cretaceous, related to today's lizards and snakes. Not dinosaurs, though they died out at the same time.
- Read more on this site →Source: Wikipedia
Fossils and how they're studied
- Fossil
- The remains or traces of ancient life preserved in rock: not only bones, but also teeth, eggs, skin impressions and footprints.
- Read more on this site →Source: Wikipedia
- Permineralization
- Groundwater carries minerals into the pores of buried bone, where they crystallize until the bone is hard and heavy like stone. It is how most dinosaur bones became fossils.
- Read more on this site →Source: Wikipedia
- Trace fossil
- Traces an animal left while alive, such as footprints, nests and droppings, which record behavior rather than just body shape.
- Read more on this site →Source: Wikipedia
- FormationGeological formation
- A body of rock with the same character and age that is large enough to map, such as the Sao Khua Formation in northeastern Thailand. Dinosaurs from one formation lived in the same region at roughly the same time.
- Read more on this site →Source: Wikipedia
- Radiometric dating
- Measuring the age of rock from radioactive elements that decay at a steady rate, such as uranium in zircon from volcanic ash, to date the layers above or below a fossil.
- Read more on this site →Source: Wikipedia
- Paleontology
- The study of ancient life through fossils; the scientists who do it are paleontologists.
- Source: Wikipedia
- Paleoart
- Art that brings extinct animals back to life following the fossil evidence; where there is none, such as skin color, the artist makes a reasoned guess.
- Source: Wikipedia
Geologic time
- Mesozoic Era
- The span from 251.9 to 66 million years ago, divided into the Triassic, Jurassic and Cretaceous, often called the age of dinosaurs.
- Read more on this site →Source: Wikipedia
- Triassic
- 251.9–201.4 million years ago. The first dinosaurs appeared, while nearly all land was still joined in the supercontinent Pangaea.
- Read more on this site →Source: Wikipedia
- Jurassic
- 201.4–145 million years ago, when giant sauropods and Stegosaurus thrived and the first birds appeared.
- Read more on this site →Source: Wikipedia
- Cretaceous
- 145–66 million years ago, the last period of the non-avian dinosaurs. Most named Thai dinosaurs come from it, and flowering plants spread.
- Read more on this site →Source: Wikipedia
- K–Pg extinctionCretaceous–Paleogene extinction
- The event 66 million years ago when an asteroid hit the Earth and about three-quarters of species died out, including all non-avian dinosaurs.
- Read more on this site →Source: Wikipedia
Scientific names
- Genus and speciesGenus / species
- A scientific name has two parts, as in Tyrannosaurus rex: the genus, then the species. This site counts dinosaurs by genus.
- Read more on this site →Source: Wikipedia
- Holotype
- The fossil a new species is named from, kept in a museum or research institution so other scientists can check which animal the name refers to.
- Read more on this site →Source: Wikipedia