Theropods Week 2

Abelisauridae

The other branch of Abelisauroidea; they were top predators during the Late Cretaceous of South America, India, Madagascar, and Europe. They have horns and spikes as well as short round snouts, thickened teeth and short, stocky arms. Well known members include Carnotaurus, Manjungasaurus and Abelisaurus

Abelisauroidea

Group within Ceratosauria that emerged during the Jurassic that include heavily cranially ornamented predators such as Carnotaurus and Majungasaurus. Other characterisitcs include a large mandibular fenestrae, femoral flange, special vertebral prongs, a round humeral head and small teeth with large neck muscles.

Allosauridae

Clade of carnosaurs with large claws and long, tridactyl hands, from the Late Jurassic; include Allosaurus and the 13 metre long Saurophaganax of North America and Europe.

Carcharodontosauria

Carcharodontosauria were the dominant carnosaurs in the Cretaceous and are composed of two major groups: Carcharodontosauridae and Neovenatoridae.

Carcharodontosauridae

Among the largest theropod dinosaurs that ever existed, they were specilaised for predation of the huge herbivorous sauropods with which they coexisted. Include Giganotosaurus and Carcharodontosaurus.

Carnosauria

Large theropods that were top predators from the Middle Jurassic to the Early Cretaceous of Europe, Asia and America. Characterized by extra openings on the maxillae and nasals, as well as and the large size of their naris (nostril). Include the allosaurids, carcharodontosaurids and Metriacanthosaurids.

Ceratosauria

Group of large averostrans that first appeared first in the early part of the Late Jurassic, but survived to become apex predators in the Late Cretaceous of South America and Europe. Includes: elaphrosaurs, ceratosaurids, noasaurids and abelisaurids.

Ceratosauridae

Group within Ceratosauria characterized by their relatively short necks and reduced arms. Ceratosaurus and Eoabelisaurus are good examples of this group.

Coelophysidae

First major radiation of theropods in the Late Triassic; includes Coelophysis. Small predators (1-3 metres) with a furcula, grasping hands, three functional digits on hand, narrow pelvis, and a tridactyl foot with a raised hallux.

Coelophysis

Meaning 'hollow bones' this Late Triassic dinosaur shows the typical coelophysid traits and is best known from one of the world's densest bone beds at Ghost Ranch New Mexico.

Coelophysoidea

Primitive Neotheropoda group including the two branches: Coelophysidae and Dilophosauridae.

Crurotarsans

Contemporaries of the primitive Triassic theropods; these were crocodile-like animals that included the large apex predator Prestosuchus.

Cryolophosaurus

The 'Frozen Crested Lizard; this large, Early Jurassic predator was the first theropod discovered in Antarctica and has a transverse crest at the top of the skull.

dentary

Most anterior portion of the lower mandible. Entire lower jaw in mammals.

denticles

Serrations on the anterior and/or posterior edge of some theropod teeth.

Dilophosauridae

The second branch in the Coelophysoidea; this was the first major radiation of large predators in the Early Jurassic, and included the crested Dilophosaurus.

elaphrosaurs

Informal group comprising the most primitive Ceratosaurs such as Spinostropheus, Limusaurus, Elaphrosaurus, and Deltadromeus.

hallux

The first digit in the foot, usually points backwards in birds, and also in some non-avian theropods.

Herrerasaurus

One of the earliest known theropods, the medium sized predator, is known from the Late Triassic of Argentina

humerus

The upper arm bone in vertebrates

Intramandibular joint

Flexible articulation in the lower mandible of theropods (between dentary-surangular-angular).

lacrimals

Bones situated in front of both eyes that define the anterior rims of the orbits; the extension of these bones towards the upper part of the skull may have helped to make the skull stronger.

Limusaurus

Meaning 'beaked dinosaur'. This is the oldest known non-carnivorous theropod dinosaur. A small dinosaur, with greatly reduced arms, and elongated legs that are well adapted for running a beak

Mandibular fenestra

Large opening in the lower jaw. This feature is characteristic of archosaurs, but especially pronounced in some theropods.

Megalosauridae

Family inlcuding Middle Jurassic predators such as the European Megalosaurus and the North African Afrovenator, as well as Torvosaurus from the Late Jurassic of North America and Europe. They were robust and muscular, with powerful legs, short and robust arms, hands with three fingers, and had blade-like teeth with very large denticles.

Megalosauroidea

Group with elongated skulls and powerful forelimbs- protofeathers have been found in this clade. Includes two clades: Megalosauridae and Spinosauridae.

Metriacanthosauridae

Clade of carnosaurs from the Middle and Late Jurassic that includes Sinraptor of China and Lourinhanosaurus of Europe.

Neotheropoda

Clade of theropods that appeared in the Late Triassic that includes all theropods beyond the primitive forms like Herrerasaurus and Eoraptor.

Neovenatoridae

The second branch of carcharodontosauria includes primitive taxa such as Neovenator from the Early Cretaceous of Europe, and Chilantaisaurus of early Late Cretaceous China.

Noasauridae

Small, slender members of Abelisauroidea known from the Cretaceous. Members include Masiakasaurus from Madagascar (although they appear in South America, Europe and India too).

Notch

Depression between the premaxilla and maxilla that acts as a connection between the two bones giving dilophosaurids a crocodilian-like extension to the snout that may have helped with piscivory.

piscivorous

Fish-eating.

Promaxillary fenestra

Small depression or opening at the anterior of the maxilla in theropods; appeared with earliest theropods.

quadrate

Bone that form the upper part of the jaw joint in theropod dinosaurs.

Spinosauridae

Enormous predators with conical crocodile-like teeth (without serrations), long snouts, sails on their back and large thumb claws. They appear in sediments from the late Early to middle Late Cretaceous of Europe, Northern Africa and Brazil. Some examples are Baryonyx, Suchomimus, and Spinosaurus.

Stereoscopic vision

Overlapping fields of sight from each eye that is essential to predators, as it gives them depth perception and three dimensional recognition of prey.

Tetanurae

The 'stiff tail' dinosaurs include the Megalosauroidea and Avetheropoda. They had teeth restricted to the front of the jaws, very large hands and interlocking tail vertebrae in at least the distal half of the tail.