TroodonTroodon (ˈtroʊ.ədɒn ; Troödon in older sources) is a former wastebasket taxon and a potentially dubious genus of relatively small, bird-like theropod dinosaurs definitively known from the Campanian age of the Late Cretaceous period (about 77 mya). It includes at least one species, Troodon formosus, known from Montana. Discovered in October 1855, T. formosus was among the first dinosaurs found in North America, although it was thought to be a lizard until 1877.
OrnithomimosauriaAutomatic taxobox | name = Ornithomimosaurs | fossil_range = Cretaceous, | image = Ornithomimosauria Diversity.jpg | image_upright = 1.15 | image_caption = Collection of seven ornithomimosaurs, clockwise from top left: Gallimimus, Anserimimus, Ornithomimus, Deinocheirus, Harpymimus, Struthiomimus and "Gallimimus mongoliensis" | taxon = Ornithomimosauria | authority = Barsbold, 1976 | subdivision_ranks = Subgroups | subdivision = *Haplocheirus? Nedcolbertia Nqwebasaurus Thecocoelurus? Valdoraptor? Macrocheiriformes Cuesta et al.
TheropodaTheropoda (θɪəˈrɒpədə; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally carnivorous, although a number of theropod groups evolved to become herbivores and omnivores. Theropods first appeared during the Carnian age of the late Triassic period 231.4 million years ago (Ma) and included the majority of large terrestrial carnivores from the Early Jurassic until at least the close of the Cretaceous, about 66 Ma.
DromaeosauridaeDromaeosauridae (ˌdrɒmi.ə'sɔrɪdiː) is a family of feathered Coelurosaurian theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek δρομαῖος (), meaning 'running at full speed, swift', and σαῦρος (), meaning 'lizard'. In informal usage, they are often called raptors (after Velociraptor), a term popularized by the film Jurassic Park; several genera include the term "raptor" directly in their name, and popular culture has come to emphasize their bird-like appearance and speculated bird-like behavior.
TroodontidaeAutomatic taxobox | name = Troodontids | fossil_range = Middle Jurassic–Late Cretaceous, | image_caption = Collection of four troodontids, clockwise from top left: Mei, unnamed Alaskan troodontid, Jianianhualong, Sinovenator. | image = Troodontidae.jpg | taxon = Troodontidae | authority = Gilmore, 1924 | type_species = Troodon formosus | type_species_authority = Leidy, 1856 | subdivision_ranks = Clade | subdivision = *Albertavenator Almas Archaeornithoides? Geminiraptor Hesperornithoides Jianianhualong Koparion? Liaoningvenator Paronychodon? Papiliovenator Polyodontosaurus Sinornithoides Talos Tochisaurus Xixiasaurus Jinfengopteryginae Sinovenatorinae Troodontinae | synonyms = *Saurornithoididae Barsbold, 1974 Troodontidae tro:.
TyrannosauroideaTyrannosauroidea (meaning 'tyrant lizard forms') is a superfamily (or clade) of coelurosaurian theropod dinosaurs that includes the family Tyrannosauridae as well as more basal relatives. Tyrannosauroids lived on the Laurasian supercontinent beginning in the Jurassic Period. By the end of the Cretaceous Period, tyrannosauroids were the dominant large predators in the Northern Hemisphere, culminating in the gigantic Tyrannosaurus.
TyrannosaurusTyrannosaurus is a genus of large theropod dinosaur. The species Tyrannosaurus rex (rex meaning "king" in Latin), often called T. rex or colloquially T-Rex, is one of the best represented theropods. It lived throughout what is now western North America, on what was then an island continent known as Laramidia. Tyrannosaurus had a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the Maastrichtian age of the Upper Cretaceous period, 68 to 66 million years ago.
ArchaeopteryxArchaeopteryx (ˌɑːrkiːˈɒptərᵻks; old-wing), sometimes referred to by its German name, "Urvogel" ( Primeval Bird), is a genus of avian dinosaurs. The name derives from the ancient Greek (archaīos), meaning "ancient", and (ptéryx), meaning "feather" or "wing". Between the late 19th century and the early 21st century, Archaeopteryx was generally accepted by palaeontologists and popular reference books as the oldest known bird (member of the group Avialae). Older potential avialans have since been identified, including Anchiornis, Xiaotingia, and Aurornis.
DinosaurDinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 245 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is a subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya and their dominance continued throughout the Jurassic and Cretaceous periods.
