Dinosaurs Glossary
Amniote - A tetrapod vertebrate that has eggs that can be laid on land removing the need to return to the water for spawning. Also the young hatch out formed like if not the same as the parents, bypassing the larval stage commonly seen in amphibians.
Amphibian - A creature that can exist in both land and water and will often share its time between the two.
Amphibious – Displaying the ability to live both in water and on the land, although this term is not exclusive to amphibians.
Ankylosaur - Any of the members of ankylosauria, the armoured group of ornithiscian dinosaurs that appeared from the Jurassic to the Cretaceous.
Apex Predator – An apex predator is one that appears at the top of the food chain. Usually they have no predators except possibly other and larger members of their own species.
Bipedal - A creature that primarily walks on two legs.
Cannibalism – The act of one creature eating another of its own species.
Carnivore - A creature that feeds on other animals.
Ceratopsian - A group of dinosaurs that are characterised by having frills around their necks. They include dinosaurs such as Einiosaurus, Protoceratops and Zuniceratops.
Cetacean – A group of mammals that include dolphins, porpoises and whales.
Chordata - The phylum that all vertebrates belong too. A small number of invertebrates also belong to this group.
Coprolite - Coprolites are fossilised dung. They offer valuable insights into the diets of ancient animals, and can even come up with the fossilised remains of animals that had been eaten by predators.
Crocodilian - A term used to describe features that are similar to crocodiles, such as skin or jaws.
Diapsid - Reptiles that have two holes that form the temporal fenestra in their skulls. Diapsid means ‘two arches’. They first appeared 300 million years ago and today they include the birds, crocodiles, lizards, snakes and tuatara.
Digitigrade – This is where the metatarsals (foot bones) are arranged in a way to extend the length of the lower leg, providing more spring and a faster running gait. This is the opposite of plantigrade.
Dinosaur - Any of the animals that belong to the Dinosauria group.
Dorsal - A descriptive word used when in reference to the back of an animal. For example, Dimetrodon had dorsal spines that formed a sail on its back.
et al - An abbreviation used to mean ‘and others’. This is commonly used when someone names a creature also had assistance from others too numerous to name in frequent usage.
Femur - The thighbone in animals.
Fenestrae - The openings inside of a skull that generally allow for the placement of soft tissues and organs such as eyes. There can be great variety in size and proportion from one species to another depending upon evolutional adaptations.
Gastrolith - Gastroliths are stones swallowed by animals to aid with the digestive process. They work by grinding plant matter inside of the stomach and are often found in animals that lack the ability to chew their food in their mouths.
Genus - A word used to describe an animal species, but can be further broken down to sub-species. Example; A Stegosaurus Stenops and a Stegosaurus ungulatus are slightly different to one another, but are both classed as Stegosaurus, and as such fall under the same genus. A Kentrosaurus on the other hand is a stegosaur, but different from Stegosaurus itself and as such is given its own genus that is different from Stegosaurus.
Gigantothermy - Gigantothermy is a term which is used to describe animals that are for lack of a better term cold blooded, but are more easily able to maintain a high body temperature due to the fact that they have a smaller body surface area to volume ratio. This is often seen in larger cold blooded animals today, and is thought by many to be applicable to extinct animals such as the larger dinosaurs, giving them a metabolism approaching that of a warm blooded creature. Gigantothermy is also referred to as ectothermic homeothermy.
Gondwana - A supercontinent that was formed from the southern half of the Pangaea supercontinent. It was composed of modern day, South America, Africa, Arabian Peninsula, Indian sub-continent, Australia, and Antarctica.
Herbivore - A creature that feeds upon plants.
Holotype – A specimen of an organism that was used in the identification and naming of a species. Further recovered examples of a species are examined against the description of the holotype to see if they represent the same creature.
ICZN – International Commission on Zoological Nomenclature. The ICZN governs the naming of animals, making sure that no two animals may have the same name.
Insectivore - A carnivore that specialises in eating insects.
Juvenile - A juvenile is a younger sexually immature specimen of an organism. An organism ceases to be juvenile when it grows to full size and sexual maturity.
Keystone species - This is term used to refer to animals that have a big impact upon their environment, and if said species disappears the environment will change. For example, it can be used to refer to a predator that keeps the number of environment damaging herbivores down. Another example would be a low browsing herbivore that prevents trees from growing tall, maintaining grassy plains.
Labyrinthodont - A member of Labyrinthodontia (maze toothed) group of amphibians. Terrestrial vertebrates today are considered to be descended from them.
Laurasia - A supercontinent that was formed from the northern half of the Pangaea supercontinent. It was composed of modern day North America and Eurasia.
Locomotion – The process of how an organism moves itself from one location to another.
Marine - Term used to describe organisms that are aquatic.
Mesozoic - The geological era that is composed of the Triassic, Jurassic and Cretaceous periods, notable for the evolution and extinction of the dinosaurs.
Nomen dubium - Latin for doubtful name. This term is sometimes used for animals that cannot be definitively proven to belong to a certain group.
Omnivore - A creature that can eat both animals and plants.
Organism - A living thing such as an animal, plant, fungus or micro-organism.
Ornithischian - Used to reference a dinosaur that is a member of the ornithischia, or ‘bird hipped’ group of dinosaurs.
Osteoderm - A bony growth found in the skin of some animals and sometimes referred to as a ‘scute’. They can form anything from specialised scales to defensive armour.
Oviparous – A creature that lays eggs which then hatch outside the body. The opposite to viviparous.
Palaeobotany – The study of ancient plants.
Palaeontology – The study of ancient organisms.
Palaeopathology – The study of how a fossilised animal died, but also encompassing the study of injuries, if they healed, and what impact they had on the creature.
Palaeozoic - The Palaeozoic is a geological era that predated the Mesozoic. It is comprised of the Permian, Carboniferous, Devonian, Silurian, Ordovician and Cambrian stages. The Palaeozoic marked a great diversification in life forms, including the first terrestrial life.
Pangaea - The supercontinent that existed when all of the world’s landmasses were joined together to form a single land mass. Eventually Pangaea broke up with tectonic plate movement that would go onto form the world as we know it today.
Pelagic – Term used to reference organisms that typically live in areas of open water as opposed to coastal locations.
Petrification - This is a fossilisations process where silica impregnates organic material, converting it to stone. All organisms can be petrified, but wood is especially susceptible to this process.
Piscivore – A carnivore that specialises in the eating of fish.
Plantigrade – This is a foot arrangement where the metatarsals (foot bones) are in contact with the ground. This is the opposite of digitigrade.
Proto feathers - These are filament hair structures that are generally considered to have evolved for the purpose of insulation. Because proto feathers would be more downy than developed with a rigid rachis, they were not capable of producing lift to allow a creature to fly. They would however allow for the eventual evolution of flight capable feathers that we see in most modern birds today.
Pterosaur - Any of the flying reptiles of the Mesozoic Era.
Pycnofibres - Hair like filaments that are found on the bodies of some pterosaurs. Although pycnofibres are not like the hair seen in mammals, they still served as insulation.
Recurved teeth – Teeth that curve backwards towards the throat. These teeth help prevent food from moving forwards and out of the mouth, and can be commonly found in predatory animals.
Saurischian - Used to reference a dinosaur that is a member of the saurischia, or ‘lizard hipped’ group of dinosaurs. It is actually from this group that birds are thought to have evolved from as opposed to the ornithiscia.
Sauropoda – A group of dinosaurs known for having extremely long necks and a quadrupedal stance.
Scleral rings - These are growths of cartilage or bone that form rings inside of the eyes, helping to keep its shape. They are commonly found in fish, reptiles and birds, and fossilised scleral rings can help accurately determine the size of the eyes in extinct animals that had them.
Scute - See ‘Osteoderm’.
Subadult - A subadult is a juvenile that is becoming sexually mature, but may not yet be fully grown.
Synonym - A synonym is another name for an existing creature that has already been named. Example; Apatosaurus (1877) and Brontosaurus (1879) were once considered two separate species. When further study showed them to be the same creature, the older name of Apatosaurus replaced Brontosaurus as the species name. Apatosaurus is now used as the name for this creature, but Brontosaurus is retained as a synonym, so that older texts referencing this animal are not misunderstood as talking about a separate species. This also prevents Brontosaurus from being reused and creating even more confusion.
Terrestrial - Term used to refer to organisms that live on the land.
Tetrapod - Four limbed vertebrates. On this site the term is usually applied to the early terrestrial amphibians.
Theropod - A group of bipedal dinosaurs that belong to the saurischia group.
Type species – The type creature for defining a genus. Multiple species may be assigned to a genus, but the type species is used as the defining guide as to whether a new discovery is assigned to an existing genus, or assigned to a new genus of its own.
Quadrupedal - Animals that primarily walk upon all four legs.
Vomeronasal organ (Jacobsan organ) - Is an auxiliary olfactory (smell) organ.
Viviparous - A term used to describe animals that give birth to live young as opposed to laying eggs. The opposite to oviparous.
Wastebasket Genus - A term used for when animals are not known to fit in exactly to an existing group so they are ‘dumped’ into a more generic group where they remain until further study can determine where they belong. Many early fossils of dinosaurs especially suffered from this.
