? Theropoda Conservation status: Fossil
T. rex foot Picture taken at Field Museum of Natural History, Chicago
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Sauropsida Superorder: Dinosauria Order: Saurischia Suborder: Theropoda Marsh, 1881
Subdivisions
?Eoraptor Herrerasauria Coelophysoidea Ceratosauria Cryolophosaurus Spinosauridae Carnosauria Coelurosauria

Theropods ("beast foot") are a group of bipedal saurischian dinosaurs. Although they were primarily carnivorous, it is believed a number of theropod families evolved herbivory during the Cretaceous. Theropods first appear during the Carnian age of the Late Triassic (about 220 million years ago), and were the sole large terrestrial Carnivores from the Early Jurassic until the close of the Cretaceous (65 million years ago). Today, they are represented by the 9,300 living species of birds, which evolved in the Late Jurassic from small specialized coelurosaurian dinosaurs. T. rex foot, picture taken at Field Museum of Natural History, Chicago The T. rex is nicknamed Sue in honor of its discoverer. ... Binomial name Tyrannosaurus rex Osborn, 1905 Tyrannosaurus rex (ty-RAN-o-sawr-us) meaning king tyrant lizard because of its size and large teeth and claws (Greek tyrannos = tyrant + sauros = lizard; Latin rex = king), also known colloquially as T. rex and The King of the Dinosaurs, was a giant carnivorous... Field Museum of Natural History, Chicago The Field Museum of Natural History, in Chicago, Illinois, USA, sits on Lake Shore Drive next to Lake Michigan, part of a scenic complex known as Museum Campus Chicago. ... Chicago (officially named the City of Chicago) is the third largest city in the United States (after New York City and Los Angeles), with an official population of 2,896,016, as of the 2000 census. ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria (coral, jellyfish, anenomes) Placozoa (trichoplax) Subregnum Bilateria (bilateral symmetry) Acoelomorpha (basal) Orthonectida (parasitic to flatworms, echinoderms, etc. ... Typical Classes Subphylum Urochordata - Tunicatas Ascidiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... Orders See text. ... Orders Saurischia    Sauropodomorpha    Theropoda Ornithischia Dinosaurs are giant reptiles that dominated the terrestrial ecosystem for most of their 165-million year existence. ... Groups Sauropodomorpha    Saturnalia    Prosauropoda    Sauropoda Theropoda    Eoraptor    Herrerasauridae    Ceratosauria    Tetanurae       Avis (extant) Saurischians (from the Greek Saurischia meaning lizard hip) are one of the two orders/branches of dinosaurs. ... Othniel Charles Marsh (October 29, 1831 - March 18, 1899) was one of the pre-eminent paleontologists of the 19th century, who discovered and named many fossils found in the American West. ... Binomial name Eoraptor lunensis Sereno, Rogers, Forster & Monetta, 1993 Eoraptor lunensis was one of the worlds earliest dinosaurs. ... Genera Staurikosaurus Aliwalia Herrerasaurus Spondylosoma Chindesaurus ? Caseosaurus Herrerasaurs are among the oldest known dinosaurs, appearing in the fossil record about 228 million years ago (mid-Triassic). ... Families Coelophysidae Coelophysoids were common dinosaurs of the Late Triassic and Early Jurassic periods. ... The Ceratosauria are a group of Theropod dinosaurs defined as all theropods sharing a more recent common ancestry with Ceratosaurus than with birds. ... Binomial name Cryolophosaurus ellioti (Hammer, 1994) Cryolophosaurus ellioti (cry-oh-LOAF-oh-SORE-us, meaning cold crested lizard) is a large bipedal dinosaur with a bizarre crest running across its head that looks like a Spanish comb. ... Spinosauridae is a subdivision of the Theropods. ... Families Allosauridae    Allosaurinae    ?Carcharodontosaurinae Sinraptoridae Carnosauria is a sub-group of Theropoda, a group of predatory dinosaurs. ... Subclades Nqwebasaurus Proceratosaurus Tyrannoraptora ?Coeluridae ?Compsognathidae Tyrannosauroidea Maniraptoriformes [incertae sedis] Alvarezsauridae Maniraptora Ornithomimosauria Coelurosauria is a group of theropod dinosaurs that includes the subgroups Tyrannosauridae, Ornithomimidae, and Maniraptora. ... Groups Sauropodomorpha    Saturnalia    Prosauropoda    Sauropoda Theropoda    Eoraptor    Herrerasauridae    Ceratosauria    Tetanurae       Avis (extant) Saurischians (from the Greek Saurischia meaning lizard hip) are one of the two orders/branches of dinosaurs. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... A deer and two fawns feeding on some foliage In zoology, a herbivore is an animal that is adapted to eat primarily plant matter (rather than meat). ... The Carnian is a stage on the geologic time scale occuring from 228 +/- 2 to 216. ... The Triassic is a geologic period that extends from about 245 to 202 Ma (million years ago). ... Lower Jurassic (also known as Lias) is the earliest of three epochs of the Jurassic period. ... The Cretaceous period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic period, about 146 million years ago (Ma), to the beginning of the Paleocene epoch of the Tertiary period (65. ... Orders Many - see section below. ... Upper Jurassic (also known as Malm) was an epoch of the Jurassic geologic period. ... Coelurosauria is a group of theropod dinosaurs that includes the subgroups Tyrannosauridae, Ornithomimidae, and Maniraptora. ...

Among the features linking theropods to birds are the three-toed foot, a wishbone, air-filled bones, and (in some cases) feathers and brooding of the eggs.

Evolutionary history

During the late Triassic, a number of primitive proto-theropod and theropod dinosaurs existed and evolved alongside each other.

The earliest and most primitive of the carnivorous dinosaurs are Eoraptor of Argentina, and the Herrerasaurs known so far from the early late Triassic (Late Carnian to Early Norian) of North and South America (and possibly also India and Southern Africa), and characterised by a mosaic of primitive and advanced features. Experts disagree over whether these animals are basal theropods, basal saurischians, or prior-to the saurischian-ornithischian split. Binomial name Eoraptor lunensis Sereno, Rogers, Forster & Monetta, 1993 Eoraptor lunensis was one of the worlds earliest dinosaurs. ... Genera Staurikosaurus Aliwalia Herrerasaurus Spondylosoma Chindesaurus ? Caseosaurus Herrerasaurs are among the oldest known dinosaurs, appearing in the fossil record about 228 million years ago (mid-Triassic). ... The Carnian is a stage on the geologic time scale occuring from 228 +/- 2 to 216. ... The Norian Stage was a portion of the Triassic geological period. ... In phylogenetics, basal members of a group are subgroups that diverged very early from the others. ...

The earliest and most primitive unambiguous theropods (or alternatively, Eutheropods - "True Theropods") are the Coelophysidae, a group of widely distributed, lightly built and apparently gregarious (Coelophysis, Syntarsus) animals that including not only smallish hunters like Coelophysis, but larger (6 meters) predators like Dilophosaurus. These successful animals continued from the Late Carnian (early Late Triassic) through to the Toarcian (late Early Jurassic). Although in the early cladistic classifications they were included under the Ceratosauria and considered a side-branch of more advanced theropods (e.g. Rowe & Gauthier 1990), they may have been ancestral to all other theropods (which would make them a paraphyletic assemblage (e.g. Mortimor 2001, Carrano et al 2002). Hello Species (type) (junior synonym) (junior synonym) One of the earliest known dinosaurs, Coelophysis (see-law-FYS-iss) meaning hollow form in reference to its hollow bones (Greek koilos = hollow + physis = form) is a small, carnivorous biped from North America. ... Dilophosaurus wetherilli (dy-LOH-fo-sawr-us) meaning two-crested lizard, because it had two crests (Greek di = two + lophos = crest + sauros = lizard) was an early Jurassic theropod dinosaur. ... The Toarcian Stage was the last faunal stage of the Early Jurassic period. ... Lower Jurassic (also known as Lias) is the earliest of three epochs of the Jurassic period. ... Greek clados = branch) or phylogenetic systematics is a branch of biology that determines the evolutionary relationships of living things based on derived similarities. ... The Ceratosauria are a group of Theropod dinosaurs defined as all theropods sharing a more recent common ancestry with Ceratosaurus than with birds. ... Paraphyletic - Wikipedia /**/ @import /skins-1. ...

The somewhat more advanced true Ceratosauria (including Ceratosaurus and Carnotaurus) appear during the Early Jurassic, and continued through to the Late Jurassic in Laurasia, competing quite well alongside their more advanced tetanuran relatives, and - in the form of the abelisaur lineage - the end of the Cretaceous in Gondwana Binomial name Ceratosaurus nasicornis Marsh, 1884 Species Ceratosaurus (horned lizard) is a predatory dinosaur from the Late Jurassic Morrison Formation of North America. ... Binomial name Carnotaurus sastrei Bonaparte, 1985 Carnotaurus (kahrn-oh-TAWR-us) meaning meat-eating bull, referring to its distinct bull-like horns (Latin carn = flesh + taurus = bull) was a large predatory dinosaur, similar to a Tyrannosaurus rex with a head distantly resembling a bulls. ... Laurasia was a supercontinent that broke off from the Pangaean supercontinent in the late Mesozoic era. ... Species See text Abelisaurs were a family of Ceratosaurian dinosaurs which lived all over the southern hemisphere (with the exeption of Tarascosaurus in Southern Europe) during the Cretaceous period. ... Pangea broke into the two supercontinents, Laurasia and Gondwana The southern supercontinent Gondwana (originally Gondwanaland) included most of the landmasses which make up todays continents of the southern hemisphere, including Antarctica, South America, Africa, Madagascar, India, Arabia, Australia-New Guinea and New Zealand. ...

The Tetanurae are more specialised again than the Ceratosaurs. They are subdivided into Spinosauroidea or Torvosauroidea (originally called "Megalosaurs") which were most common during the Middle Jurassic but continue to the Middle Cretaceous, and the Avetheropoda. The Latter clade - as their name indicates - are more closely related to birds, and are again divided into the Carnosauria (including Allosaurus) and the Coelurosauria, a very large and diverse dinosaur group that was especially common during the Cretaceous. Subclades Neotetanurae   Carnosauria   Coelurosauria Spinosauroidea   Megalosauridae   Spinosauridae   Torvosauridae // Definition Tetanurae, meaning stiff tails, was named by Gauthier (1986) for a large group of theropod dinosaurs. ... Families Spinosauridae Megalosauridae Megalosauroidea was a superfamily of tetanuran theropod dinosaurs that lived from the Middle Jurassic to the Late Cretaceous period. ... A clade is group of organisms which share a common ancestor and which includes all decendents of that ancestor. ... Families Allosauridae    Allosaurinae    ?Carcharodontosaurinae Sinraptoridae Carnosauria is a sub-group of Theropoda, a group of predatory dinosaurs. ... Species (type) Allosaurus (AL-oh-sore-us) meaning “different lizard”, because its vertebrae were different from those of all other dinosaurs (Greek allos = different + sauros = lizard), was a large carnivorous dinosaur with a length of up to 12 m (39 ft). ... Subclades Nqwebasaurus Proceratosaurus Tyrannoraptora ?Coeluridae ?Compsognathidae Tyrannosauroidea Maniraptoriformes [incertae sedis] Alvarezsauridae Maniraptora Ornithomimosauria Coelurosauria is a group of theropod dinosaurs that includes the subgroups Tyrannosauridae, Ornithomimidae, and Maniraptora. ...

Thus during the late Jurassic there were no less than four distinct lineages of theropods - Ceratosaurs, Torvosaurs, Allosaurs (Carnosaurs), and Coelurosaurs, preying on the abundance of small and large herbivorous dinosaurs. All four groups survived into the Cretaceous, although only two - the Abelisaurs and the Coelurosaurs - seem to have made it to end of the period, where they were geographically separate; the Abelisaurs in Gondwana, and the Coelurosaurs in Asiamerica.

Of all the theropod groups, the Coelurosaurs were by far the most diverse. Some Coelurosaur clades that flourished during the Cretaceous are: tyrannosaurs, including the famous Tyrannosaurus rex, the dromaeosaurs, including Velociraptor and Deinonychus, which are remarkably similar in form to the Archaeopteryx (Ostrom 1969, Paul 1988, Dingus & Rowe 1998), the superficially dromaeosaur-like Troodontidae, the omnivorous oviraptorosaurs, the herbivorous ornithomimids ("ostrich dinosaurs") and Therizinosauridae (with Falcarius utahensis as a recently discovered non-missing link between the carnivores and the vegetarian forms (Kirkland et al 2005)), and the birds, the only dinosaur lineage to survive the end Cretaceous mass-extinction. While the roots of these various groups must have been in the Late, or possibly even the Middle Jurassic, they only became abundant during the early Cretaceous. One paleontologist and popular writer, Gregory S. Paul, has suggested (Paul 1988, 2002) that these advanced theropods were actually descended from flying dinosaurs or proto-birds like Archaeopteryx that lost the ability to fly and returned to a terrestrial habitat. While this hypothesis can explain why coelurosaurs are so rare during the Jurassic, Paul's theory has not caught on among other vertebrate paleontologists. Genera Dilong Eotyrannus Alectrosaurus Albertosaurus Daspletosaurus Gorgosaurus Tarbosaurus Tyrannosaurus The tyrannosaurids were a family of dinosaurs whose name is derived from the Greek words trannos, meaning tyrant; and sauros, meaning lizard. ... Binomial name Tyrannosaurus rex Osborn, 1905 Tyrannosaurus rex (ty-RAN-o-sawr-us) meaning king tyrant lizard because of its size and large teeth and claws (Greek tyrannos = tyrant + sauros = lizard; Latin rex = king), also known colloquially as T. rex and The King of the Dinosaurs, was a giant carnivorous... Genera Achillobator Adasaurus Bambiraptor Cryptovolans Dromaeosaurus Deinonychus Gracilraptor Microraptor Pyroraptor Saurornitholestes Sinornithosaurus Utahraptor Variraptor Velociraptor Among the dinosaurs, the Dromaeosaurids or Dromaeosauridae (running lizards) were fast and agile dominant carnivores throughout the Cretaceous period. ... Binomial name Velociraptor mongoliensis Osborn, 1924 Velociraptor mongoliensis (pronounced , or approximately veh-LOSS-ih-RAP-tor) meaning swift thief, referring to its speed and grasping hands (Latin velocis = swift + raptor = thief) was a small, agile, and slender theropod dinosaur species from the Late Cretaceous Period (Campanian age), with a slightly... Binomial name Deinonychus antirrhopus Ostrom, 1969 Deinonychus antirrhopus (pronounced , or approximately dyn-ON-ik-us) meaning terrible claw, referring to the large claws on its feet (Greek deinos = terrible + onyx, onychos = claw) was a jaguar-sized, carnivorous dromaeosaurid dinosaur species from the Early Cretaceous Clovery Formation of Montana. ... Troodontidae is a clade of bird-like theropod dinosaur which have been allied, at various times, with nearly every major coelurosaurian lineage. ... The Oviraptorosauria are a group of beaked, feathered dinosaurs from the Cretaceous of Asia and North America. ... Genera Anserimimus Archaeornithomimus Deinocheirus ? Dromiceiomimus Gallimimus Garudimimus Harpymimus Ornithomimus Pelecanimimus Struthiomimus Ornithomimids (Bird mimics) or members of the Ornithomimidae family are theropod dinosaurs, like Gallimimus. ... Genera Alxasaurus elesitaiensis Chilantaisaurus zheziangensis Enigmosaurus mongoliensis Erlikosaurus andrewsi Nanshiungosaurus brevispinus Nanshiungosaurus bohlini Nothronychus mckinleyi Segnosaurus galbinensis Therizinosaurus cheloniformis Falcarius utahensis Therizinosauridae is a family of dinosaur species with related characteristics, belonging to the more including group of the Therizinosauroidea. ... Binomial name Falcarius utahensisSampson & Zanno, 2005 Falcarius utahensis is a newly discovered dinosaur species found in east-central Utah, in the United States, in 2005. ... Orders Many - see section below. ... Gregory S. Paul (born 1954) is a freelance paleontologist, author and illustrator. ... Binomial name Archaeopteryx lithographica Meyer, 1861 Archaeopteryx lithographica (ahr-kee-OP-ter-ix) meaning ancient wing(Greek archaio = ancient + pteryx = wing), from the Late Jurassic of Germany, is the earliest and most primitive known bird. ...

Classification

• Order Saurischia
  • SUBORDER THEROPODA
    • ?Eoraptor
    • ?Superfamily Herrerasauria
    • Guaibasaurus
    • Neotheropoda
      • Superfamily Coelophysoidea
      • Ceratosauria
        • Family Ceratosauridae
        • Family Noasauridae
        • Family Abelisauridae
      • Tetanurae
        • ?Cryolophosaurus
        • Superfamily Megalosauroidea
          • Family Megalosauridae
          • Family Spinosauridae
        • Avetheropoda
          • Carnosauria
            • Family Sinraptoridae
            • Family Allosauridae
            • Family Carcharodontosauridae
          • Coelurosauria
            • Family Coeluridae
            • Superfamily Tyrannosauroidea
            • Superfamily Ornithomimosauria
            • Maniraptora

Groups Sauropodomorpha    Saturnalia    Prosauropoda    Sauropoda Theropoda    Eoraptor    Herrerasauridae    Ceratosauria    Tetanurae       Avis (extant) Saurischians (from the Greek Saurischia meaning lizard hip) are one of the two orders/branches of dinosaurs. ... Binomial name Eoraptor lunensis Sereno, Rogers, Forster & Monetta, 1993 Eoraptor lunensis was one of the worlds earliest dinosaurs. ... Genera Staurikosaurus Aliwalia Herrerasaurus Spondylosoma Chindesaurus ? Caseosaurus Herrerasaurs are among the oldest known dinosaurs, appearing in the fossil record about 228 million years ago (mid-Triassic). ... Guaibasaurus (Guaiba Lizard) was a Herrerasaur from Triassic South America. ... Families Coelophysidae Coelophysoids were common dinosaurs of the Late Triassic and Early Jurassic periods. ... The Ceratosauria are a group of Theropod dinosaurs defined as all theropods sharing a more recent common ancestry with Ceratosaurus than with birds. ... Abelisauridae is a family (or clade) of theropod dinosaurs. ... Subclades Neotetanurae   Carnosauria   Coelurosauria Spinosauroidea   Megalosauridae   Spinosauridae   Torvosauridae // Definition Tetanurae, meaning stiff tails, was named by Gauthier (1986) for a large group of theropod dinosaurs. ... Binomial name Cryolophosaurus ellioti (Hammer, 1994) Cryolophosaurus ellioti (cry-oh-LOAF-oh-SORE-us, meaning cold crested lizard) is a large bipedal dinosaur with a bizarre crest running across its head that looks like a Spanish comb. ... Families Spinosauridae Megalosauridae Megalosauroidea was a superfamily of tetanuran theropod dinosaurs that lived from the Middle Jurassic to the Late Cretaceous period. ... Megalosaurids were a family of tetanuran theropod dinosaurs, order Saurischia. ... Spinosauridae is a subdivision of the Theropods. ... Families Allosauridae    Allosaurinae    ?Carcharodontosaurinae Sinraptoridae Carnosauria is a sub-group of Theropoda, a group of predatory dinosaurs. ... Allosaurids were a family of medium to large sized carnivorous dinosaurs. ... Carcharodontosauridae (from the Greek Carcharodontosauros: shark-toothed lizard) is a group of carnivorous theropod dinosaurs, sometimes also referred as Carcharodontosaurinae (included within the Allosauridae), which includes some of the biggest land predators of all time, like Giganotosaurus, Carcharodontosaurus or Tyrannotitan. ... Subclades Nqwebasaurus Proceratosaurus Tyrannoraptora ?Coeluridae ?Compsognathidae Tyrannosauroidea Maniraptoriformes [incertae sedis] Alvarezsauridae Maniraptora Ornithomimosauria Coelurosauria is a group of theropod dinosaurs that includes the subgroups Tyrannosauridae, Ornithomimidae, and Maniraptora. ... Subclades Coelurus Tanycolagreus ?Compsognathinae Coeluridae is a family of generally small, carnivorous dinosaurs from the Jurassic and Cretaceous periods. ... Genera See text. ... Genera Anserimimus Archaeornithomimus Deinocheirus ? Dromiceiomimus Gallimimus Garudimimus Harpymimus Ornithomimus Pelecanimimus Shenzhousaurus Struthiomimus Ornithomimids (Bird mimics) or members of the Ornithomimidae family are theropod dinosaurs, like Gallimimus. ... Subgroups Alvarezsauria Aves Deinonychosauria Oviraptorosauria Therizinosauria Maniraptora is a group used in biological classification to cover the birds and the dinosaurs that were related to them. ...

References

• Carrano, M. T., Sampson, S. D. & Forster, C. A., (2002), The osteology of Masiakasaurus knopfleri, a small abelisauroid (Dinosauria: Theropoda) from the Late Cretaceous of Madagascar. Journal of Vertebrate Paleontology Vol. 22, #3, pp. 510-534
• Dingus, L. & Rowe, T. (1998), The Mistaken Extinction: Dinosaur Evolution and the Origin of Birds, Freeman
• Kirkland, J. I., Zanno, L. E., Sampson, S. D., Clark, J. M. & DeBlieux, D. D., (2005) A primitive therizinosauroid dinosaurs from the Early Cretaceous of Utah, Nature: Vol. 435, pp. 84-87
• Mortimer, M., (2001) "Rauhut's Thesis", Dinosaur Mailing List Archives, 4 Jul 2001
• Ostrom, J.H. (1969). Osteology of Deinonychus antirrhopus, an unusual theropod from the Lower Cretaceous of Montana, Peabody Museum Nat. History Bull., 30, 1-165
• Paul, G.S., (1988) Predatory Dinosaurs of the World Simon and Schuster Co., New York (ISBN 0671619462)
• ----- (2002) Dinosaurs of the Air (ISBN 0801867630):
• Rowe, T., & Gauthier, J., (1990) Ceratosauria. 151-168 in Weishampel, D. B., Dodson, P., & Osmólska, H. (eds.), The Dinosauria, University of California Press, Berkley, Los Angeles, Oxford.

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