THEROPODA - the CARNIVOROUS DINOSAURS


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SAURISCHIA

Characters

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The Saurischian pelvis.  Note the open acetabulum and  the anterior (to the left) pubis.  Illustration from O. C. Marsh.  1896.  The dinosaurs of North America.  16th Annual Report, U.S. Geological Survey, pp. 133-244, 84 plates.


CLASSIFICATION OF THE THEROPODA


Superorder Dinosauria
    Suborder Ornithischia
    Suborder Saurischia
        Order Sauropodomorpha
        Order Theropoda
            Eoraptor
            Neotheropoda
                Infraorder CERATOSAURIA
                Infraorder TETANURAE
                    Megalosaurus
                    Spinosauroidea
                    Avetheropoda
                        Carnosauria
                             Allosauridae
                         Coelurosauria
                            Compsognathus,Ornitholestes,Scipionyx, etc.
                            Therizinosauria
                            Arctometatarsalia
                                Tyranosauridae
                                Ornithomimosauria
                            Maniraptora
                                Oviraptosauria
                                Troodontidae
                                Dromaeosauridae
                                Aviale


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Ceratosaurus: Illustration from O. C. Marsh.  1896.  The dinosaurs of North America.


THEROPODA

Dinosaurs with a saurischian pelvis and sharp teeth and claws

Synapomorphies

  1. kinetic, flexible lower jaw
  2. large, ball-shaped occipital condyle provides extra mobility for the head [D&R p. 180]
  3.  5 or more sacral vertebrae
  4. distal part of tail is stiff
  5. digits IV and V of manus (hand) reduced to absent
  6. digits II and III of hand elongate
  7. phalanges of digit V of foot lost
  8. digit I of pes (foot) is reduced and breaks contact with ankle
  9. thin-walled, hollow limb bones and vertebrae
  10. Lachrymal bone is prominently exposed on dorsal surface of skull
  11. Gautier (1986) lists 25 synapomorphies including; extra fenestra in the maxilla; narrow elongate metatarsus; elongated zygopophyses on the vertebrae near the end of the tail; etc.

References


NOTES ON THEROPOD PALEOBIOLOGY


Eoraptor

Characters

References

Herrerasuaridae

Sereno considers the two or three genera of this family to be basal theropods.  Other suggest that they are dinosauromorphs that lack the synapomorphies of the dinosauria.  They are briefly discussed on my ancestry of the dinosaurs page.

Neotheropoda

Included taxa

characters

CERATOSAURIA 

Range

Characters

Coelophysoidea. 

Neoceratosauria. 


TETANURAE

Included taxa

Characters

Megalosaurus

Spinosauroidea  

Characters

Example

Reference

Avetheropoda (=Neotetanurae)

Included taxa

Characters

CARNOSAURIA

Allosauroidea

Characters

Example


COELUROSAURIA

Included taxa

Characters

Primitive Coelurosaurians

ARCTOMETATARSALIA

Included taxa

Characters

Tyrannosauridae

Characters

Examples


Ornithomimosauria (Cretaceous)

Characters

Examples


Maniraptora

Characters

Included Taxa

Therizinosauria

Examples

Oviraptorosauria

Previously considered ornithomimids, now included in maniraptors. Oviraptor was first discovered in Mongolia near what was thought to be the nest of a Protoceratops, presumably intent on stealing an egg.  In fact, inside the eggs are skeletons of fetuses of OviraptorA recent discovery is of an Oviraptor on top of a nest of eggs which she may have been brooding like a bird.  To learn much more about oviraptosaurs, visit Jaime A. Headden's Qilong site.

Characters

Example

Troodontidae

Characters

Examples

Protarchaeopterix

Characters

Dromaeosauridae see Currie; 1995; Journal of Vertebrate Paleontology 15:576-591

Characters

Examples

Eumaniraptora

Characters

Caudipterix Ji, Currie, Norell, & Ji, 1998

Distribution

Reference

Sinornithosaurus 

This deinonychosaur may be the sister taxon to the birds. It has filamentous feathers.  Its arms are proportionally very long -- 80% as long as the legs.  The shoulder girdle has features like those of flying birds; it could flap its arms..

Distribution

Reference

  Avialae

Characters

Archaeopterix (late Jurassic)

Bambiraptor

Unenlagia Unenlagia

Alvarezsauria

Ornithothorraces: all other birds.  They are better adapted for powered flight

Order Enantiornithoformes (Cretaceous)

Order Hesperornithiformes


Infraclass Neornithes ("New Birds")

Characteristics
loss of teeth

Superorder PALEOGNATHAE (Cenozoic)

Characters

  1. usual absence of flight feathers
  2. paleognathous palate (large vomers, small palatines, with pterygoid-vomer articulation
  3. sternum reduced, usually without a keel
  4. pygostyle poorly developed or absent.

Taxa

  1. Aepyornis [fig. 17-21a], the elephantbird of Madagascar, stood around 3 m tall and weighed about 660 kg, 20 lb. egg, 1 ft. long, 2 gallons; herbivore
  2. Dinornis, a moa from New Zealand stood 3.6 m tall and weighed up to 300 kg, herbivore.
  3. Ostrich: largest living bird; 2.6 m tall; lives in Africa; eats plants and small animals; ostrich up to 150 kg
  4. Emu: lives in Australia and reaches 6'
  5. Cassowary: lives in Australia & New Guinea
  6. Kiwi: 3 species that live in New Zealand
  7. Rhea: South America
  8. Tinamous: only group of ratites that fly, found in South America, Central America, and Mexico

Superorder NEOGNATHAE (Cenozoic)

Characters

  1. all other living birds Table 18-1
  2. carinates - the flying birds that have a keeled sternum on which the powerful flight muscles insert. Some carinates have become flightless
  3. neognathous palate  (small vomers, large palatines, pterygoid not reaching vomer articulation)
  4. About 22 orders, including the following:
  1. Order Podicipediformes: grebes;
  2. Order Anseriformes: waterfowl
    1. including ducks, geese, and swans:
    2. Trumpeter swan is the heaviest flying bird: trumpeter swan--17 kg;
  3. Order Pelicaniformes: marine birds;
    1. including pelicans, cormorants, anhingas
  4. Order Ciconiiformes: wading birds
    1. egrets, herons, ibises, spoon bills, and storks:
    2. new world vultures are probably closely related to storks
      1. The largest flying bird was the extinct giant condor, Argentavis, a Teratornithidae (related to New World vultures) from the late Miocene of Argentina, that weighed 75 kg, stood 2 m tall and had a wingspan of up to 8 m.
  5. Order Falconiformes: birds of prey;
    1. including  hawks, eagles, falcons and Old World vultures
  6. Order Galliformes: fowl; including the chicken, turkey, grouse, and pheasants:
  7. Order Gruiformes:
    1. 12 families, including cranes, coots, rails
    2. terror cranes: extinct, flightless, giant (over 2 m tall), cursorial predators   evolved independently at least twice in the Gruiformes
      1. Diatryma: [Paleocene and Eocene of North America and Europe]
      2. Phorusrhacus [Miocene and Pliocene of South America] and Titanis [Pliocene and Pleistocene of North America]
  8. Order Charadriiformes: shorebirds; including plovers, sandpipers, gulls, terns, and skimmers:
  9. Order Gaviiformes: loons;
  10. Order Columbiformes: including pigeons, doves, and the recently extinct dodo:
  11. Order Psittaciformes: parrots and macaws;
  12. Order Strigiformes: owls;
  13. Order Apodiformes: hummingbirds and swifts;
  14. Order Piciformes: woodpeckers and toucans;
  15. Order Passeriformes: perching birds/songbirds;
    1. 64 families
    2. comprise about 1/2 of all species (4000 species) of birds,

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