Pterosaur

"Pterodactyl" redirects here. For the genus commonly called "pterodactyl", see Pterodactylus. For other uses, see Pterodactyl (disambiguation).

Pterosaur
Temporal range: Late Triassic–Late Cretaceous, 228–66 Ma
Six pterosaurs (top left to bottom right): Dimorphodon, Pterodactylus, Anurognathus, Quetzalcoatlus, Sordes, Tropeognathus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Ornithodira
Clade: †Pterosauromorpha
Order: †Pterosauria
Kaup, 1834
Subgroups[1][2]
Distribution of pterosaur fossil locations. Colored species or genera names correspond to their taxonomic group.[a]
Synonyms

Ornithosauria Seeley, 1870

Pterosaurs[b][c] are an extinct clade of flying reptiles in the order Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to 66 million years ago).[8] Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger.[9]

There were two major types of pterosaurs. Basal pterosaurs (also called 'non-pterodactyloid pterosaurs' or 'rhamphorhynchoids') were smaller animals with fully toothed jaws and, typically, long tails. Their wide wing membranes probably included and connected the hind legs. On the ground, they would have had an awkward sprawling posture, but the anatomy of their joints and strong claws would have made them effective climbers, and some may have even lived in trees. Basal pterosaurs were insectivores or predators of small vertebrates. Later pterosaurs (pterodactyloids) evolved many sizes, shapes, and lifestyles. Pterodactyloids had narrower wings with free hind limbs, highly reduced tails, and long necks with large heads. On the ground, they walked well on all four limbs with an upright posture, standing plantigrade on the hind feet and folding the wing finger upward to walk on the three-fingered "hand". They could take off from the ground, and fossil trackways show at least some species were able to run and wade or swim.[10] Their jaws had horny beaks, and some groups lacked teeth. Some groups developed elaborate head crests with sexual dimorphism.

Pterosaurs sported coats of hair-like filaments known as pycnofibers, which covered their bodies and parts of their wings. Pycnofibers grew in several forms, from simple filaments to branching down feathers. These may be homologous to the down feathers found on both avian and some non-avian dinosaurs, suggesting that early feathers evolved in the common ancestor of pterosaurs and dinosaurs, possibly as insulation.[11] In life, pterosaurs would have had smooth or fluffy coats that did not resemble bird feathers. They were warm-blooded (endothermic), active animals. The respiratory system had efficient unidirectional "flow-through" breathing using air sacs, which hollowed out their bones to an extreme extent. Pterosaurs spanned a wide range of adult sizes, from the very small anurognathids to the largest known flying creatures, including Quetzalcoatlus and Hatzegopteryx,[12][13][14] which reached wingspans of at least nine metres. The combination of endothermy, a good oxygen supply and strong muscles made pterosaurs powerful and capable flyers.

Pterosaurs are often referred to by popular media or the general public as "flying dinosaurs", but dinosaurs are defined as the descendants of the last common ancestor of the Saurischia and Ornithischia, which excludes the pterosaurs.[15] Pterosaurs are nonetheless more closely related to birds and other dinosaurs than to crocodiles or any other living reptile, though they are not bird ancestors. Pterosaurs are also colloquially referred to as pterodactyls, particularly in fiction and journalism.[16] However, technically, pterodactyl may refer to members of the genus Pterodactylus, and more broadly to members of the suborder Pterodactyloidea of the pterosaurs.[17]

Pterosaurs had a variety of lifestyles. Traditionally seen as fish-eaters, the group is now understood to have also included hunters of land animals, insectivores, fruit eaters and even predators of other pterosaurs. They reproduced by eggs, some fossils of which have been discovered.

  1. ^ Andres, B.; Clark, J.; Xu, X. (2014). "The Earliest Pterodactyloid and the Origin of the Group". Current Biology. 24 (9): 1011–16. Bibcode:2014CBio...24.1011A. doi:10.1016/j.cub.2014.03.030. PMID 24768054.
  2. ^ Baron, Matthew G. (2020). "Testing pterosaur ingroup relationships through broader sampling of avemetatarsalian taxa and characters and a range of phylogenetic analysis techniques". PeerJ. 8: e9604. doi:10.7717/peerj.9604. PMC 7512134. PMID 33005485.
  3. ^ Mark P. Witton (2013), Pterosaurs: Natural History, Evolution, Anatomy, Princeton University Press, Bibcode:2013pnhe.book.....W, ISBN 978-0-691-15061-1
  4. ^ David M. Unwin (2010), "Darwinopterus and its implications for pterosaur phylogeny", Acta Geoscientica Sinica, 31 (1): 68–69
  5. ^ Jones, Daniel (2003) [1917], Peter Roach; James Hartmann; Jane Setter (eds.), English Pronouncing Dictionary, Cambridge: Cambridge University Press, ISBN 978-3-12-539683-8
  6. ^ "Pterosaur". Merriam-Webster.com Dictionary. Merriam-Webster.
  7. ^ Colbert, Edwin H. (Edwin Harris); Knight, Charles Robert (1951). The dinosaur book: the ruling reptiles and their relatives. New York: McGraw-Hill. p. 153.
  8. ^ "Pterosaur distribution in time and space: an atlas" (PDF). Zitteliana: 61–107. 2008.
  9. ^ Elgin RA, Hone DW, Frey E (2011). "The Extent of the Pterosaur Flight Membrane". Acta Palaeontologica Polonica. 56 (1): 99–111. doi:10.4202/app.2009.0145.
  10. ^ "Pterosaur.net :: Terrestrial Locomotion". pterosaur.net. Retrieved 2020-02-01.
  11. ^ Geggel 2018-12-17T19:23:17Z, Laura (17 December 2018). "It's Official: Those Flying Reptiles Called Pterosaurs Were Covered in Fluffy Feathers". livescience.com. Retrieved 2020-02-01.{{cite web}}: CS1 maint: numeric names: authors list (link)
  12. ^ Cite error: The named reference wangetal2008 was invoked but never defined (see the help page).
  13. ^ Lawson DA (March 1975). "Pterosaur from the Latest Cretaceous of West Texas: Discovery of the Largest Flying Creature". Science. 187 (4180): 947–948. Bibcode:1975Sci...187..947L. doi:10.1126/science.187.4180.947. PMID 17745279. S2CID 46396417.
  14. ^ Buffetaut E, Grigorescu D, Csiki Z (April 2002). "A new giant pterosaur with a robust skull from the latest cretaceous of Romania" (PDF). Naturwissenschaften. 89 (4): 180–84. Bibcode:2002NW.....89..180B. doi:10.1007/s00114-002-0307-1. PMID 12061403. S2CID 15423666.
  15. ^ Benton, Michael J. (2004). "Origin and relationships of Dinosauria". In Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (eds.). The Dinosauria (2nd ed.). Berkeley: University of California Press. pp. 7–19. ISBN 978-0-520-24209-8.
  16. ^ Naish, Darren. "Pterosaurs: Myths and Misconceptions". Pterosaur.net. Retrieved June 18, 2011.
  17. ^ Alexander, David E. & Vogel, Steven (2004). Nature's Flyers: Birds, Insects, and the Biomechanics of Flight. JHU Press. p. 191. ISBN 978-0-8018-8059-9.


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