Coelurosauria

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iCoelurosaurs Fossil range: Middle Jurassic – Late Cretaceous (non-avian)
Sinosauropteryx, a compsognathid.
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Sauropsida Superorder: Dinosauria Order: Saurischia Suborder: Theropoda Infraorder: Coelurosauria von Huene, 1914
Families
See text

The Coelurosauria is a group of theropod dinosaurs that includes the subgroups Tyrannosauroidea, Ornithomimosauria, and Maniraptora.

Contents 1 Description 2 Traditional 'Coelurosaurs' 3 Classification 4 References 5 External links

[edit] Description

Coelurosaur characteristics included an extended sacrum, a distally stiffened tail and a bowed ulna. The tibia is also characteristically longer than the femur in coelurosaurs. Fossil evidence shows that all coelurosaurs were probably feathered. Prum and Brush (2002) state that feathers "originated in a lineage of coelurosaurian theropod dinosaurs including both Sinosauropteryx and birds", and that feathers probably did not exist in more primitive theropod groups, like "allosauroids, ceratosaurids, and coelophysids." [1] Thus, feathers are trait of advanced theropods (i.e., coelurosaurs), and probably originated in the basalmost members of this group.

Additionally, fossilized traces of feathers have been identified from at least one species in almost every coelurosaur lineage. Feathers are known from coelurids, tyrannosaurs, oviraptorosaurs, therizinosaurs, alvarezsaurids, dromaeosaurids, and troodontids. All known specimens in the family Scansoriopterygidae are also known from feather-bearing fossils. To date, the only group of coelurosaurs which have not shown direct evidence of feathers are the ornithomimosaurs.

Most coelurosaurs were bipedal predators and the group includes some of the largest (Tyrannosaurus) and smallest (Microraptor) carnivorous dinosaurs discovered thus far. Modern birds are classified by most palaeontologists (but not by many ornithologists (Feduccia, 1993)) as an extant group of coelurosaurs (in the subgroup Maniraptora) (Mayr et al., 2005).

Examples of the coelurosaur footprints have been found at the Lark Quarry Dinosaur Stampede, Queensland, Australia.

[edit] Traditional 'Coelurosaurs'

Like Carnosauria for large theropods, the infraorder Coelurosauria had traditionally been used as a 'dumping ground' for all small theropods but analysis, in the 1980s and 1990s, revealed that some 'coelurosaurs' were actually more primitive theropods, most notably the coelophysids. Additionally, some dinosaur groups long thought to belong to the Carnosauria, the tyrannosaurids, turned out to be giant coelurosaurs. The large, herbivorous/omnivorous segnosaurs, once thought to be related to either sauropods or ornithischians, have similarly turned out to be coelurosaurs.

Coelurosauria is phylogenetically defined as those dinosaurs sharing a more recent common ancestor with birds than with Allosaurus.[2].

[edit] Classification

• Tetanurae
  • Infraorder COELUROSAURIA
    • Tugulusaurus
    • Proceratosaurus
    • Nedcolbertia
    • Santanaraptor
    • Ornitholestes
    • Scipionyx
    • Nqwebasaurus
    • Family Coeluridae
    • Family Compsognathidae
    • Superfamily Tyrannosauroidea
    • Maniraptoriformes
      • Ornithomimosauria
      • ?Family Alvarezsauridae
      • Maniraptora
        • Therizinosauria
        • Oviraptorosauria
        • Deinonychosauria
        • Class Aves

[edit] References

• Mayr, G., B. Pohl & D.S. Peters (2005). "A well-preserved Archaeopteryx specimen with theropod features". Science 310 (5753): 1483-1486.
• Prum, R. & Brush A.H. (2002). "The evolutionary origin and diversification of feathers". The Quarterly Review of Biology 77: 261-295.

[edit] External links

• "Coelurosauria ". DinoData.
• "Lark Quarry, Queensland, Australia". Lark Quarry.