Living dinosaur

Living dinosaurs are non-avian dinosaurs that may have survived the Cretaceous–Paleogene (K–Pg) extinction event. The term is used in the scientific fields of paleontology and biology (as well as the pseudoscience of cryptozoology) to refer to different creatures. In paleontology, all non-avian dinosaurs are believed to have gone extinct during the K–Pg extinction event, 66 million years ago, but there is some scattered evidence that some may have survived into the Paleocene epoch. These alleged creatures are referred to as living dinosaurs. In biology, the term is sometimes used to describe birds, which are the only living clade of dinosaurs today. In cryptozoology, where the term is often used, it refers to any legendary or folkloric creature that resembles the dinosaurs (such as the Loch Ness Monster), which cryptozoologists allege are dinosaurs that have survived into modern times. Excluding a few controversial claims, scientists agree that all non-avian dinosaurs became extinct at the K–Pg boundary.

In paleontology

Main article: Paleocene dinosaurs

In paleontology, a living dinosaur is a dinosaur which is claimed to have survived the K–Pg extinction event, 66 million years ago, into the Paleocene epoch. The fossils of these "Paleocene dinosaurs", are found above the K–Pg boundary strata. Although almost all evidence indicates that non-avian dinosaurs all became extinct at the K–Pg boundary, there is some scattered evidence that some non-avian dinosaurs lived for a short period of time during the Paleocene epoch, supporting the claim that the event that caused the extinction of the dinosaurs was not sudden, but rather gradual.[1] Their arguments are based on the finding of dinosaur remains in the Hell Creek Formation up to 1.3 m (4.3 ft) above, therefore 40,000 years later than the K–Pg boundary.[1][2]

In general biology

Main article: Origin of birds
Archaeopteryx lithographica, a transitional fossil between dinosaurs and modern birds.

In biology, "living dinosaurs" are modern birds.[3] The designation arises from the evolutionary lineage of birds as the only clade of dinosaurs to have survived the K–Pg extinction event.[4] More specifically, they are members of Maniraptora, a group of theropods that includes dromaeosaurs and oviraptorids, among others.[5][6]

In cryptozoology

In cryptozoology, a "living dinosaur" is any legendary or folkloric creature that resembles the dinosaurs, which cryptozoologists allege are dinosaurs that have survived into modern times. Excluding a few controversial claims, scientists agree that all non-avian dinosaurs became extinct at the K–Pg boundary.[7][8] or, at most, a few hundred thousand years after, in the early Paleocene.[1][9] There is no evidence that any non-avian dinosaurs survived beyond the Cretaceous,[7][10] and there are strong arguments against the survival of populations of large dinosaurs.

Alleged living dinosaurs are typically based on interpretations of regional folklore, alleged eyewitness sightings, legends, unverified physical evidence (like footprints), and works of traditional art that supposedly depict dinosaurs.[11]

Some cryptozoologists and creationists claim that archaeological evidence supports the existence of living dinosaurs,[12] and that several archaeological artifacts, old writings, cave paintings and ancient folklores were based on the idea that man and dinosaurs lived beside each other. However, archeologists, biologists, and other fields of science do not support this idea, and view the field of cryptozoology as pseudoscience.[13][14][15]

With no fossil evidence supporting the existence of Cenozoic dinosaurs, save for the few controversial discoveries limited to the early Paleocene,[1][9] paleontologists and evolutionary scientists have not supported the existence of living dinosaurs.[16]

See also

References

  1. 1 2 3 4 Fassett, JE, Lucas, SG, Zielinski, RA, and Budahn, JR (2001). "Compelling new evidence for Paleocene dinosaurs in the Ojo Alamo Sandstone, San Juan Basin, New Mexico and Colorado, USA" (PDF). Catastrophic events and mass extinctions, Lunar and Planetary Contribution. 1053: 45–46. Retrieved 2007-05-18.
  2. ↑ Sloan, R. E., Rigby, K,. Van Valen, L. M., Gabriel, Diane (1986). "Gradual dinosaur extinction and simultaneous ungulate radiation in the Hell Creek formation". Science. 232 (4750): 629–633. Bibcode:1986Sci...232..629S. doi:10.1126/science.232.4750.629. PMID 17781415. Retrieved 2007-05-18.
  3. ↑ Norell, Mark; Mick Ellison (2005). Unearthing the Dragon: The Great Feathered Dinosaur Discovery. New York: Pi Press. ISBN 0-13-186266-9.
  4. ↑ Prum, Richard O. Prum (2008). "Who's Your Daddy". Science. 322 (5909): 1799–1800. doi:10.1126/science.1168808. PMID 19095929.
  5. ↑ Paul, Gregory S. (2002). "Looking for the True Bird Ancestor". Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds. Baltimore: Johns Hopkins University Press. pp. 171–224. ISBN 0-8018-6763-0.
  6. ↑ Xing Xu, Hailu You, Kai Du and Fenglu Han (28 July 2011). "An Archaeopteryx-like theropod from China and the origin of Avialae". Nature. 475 (7357): 465–470. doi:10.1038/nature10288. PMID 21796204.
  7. 1 2 Fastovsky, David E.; Sheehan, Peter M. (2005). "The Extinction of the Dinosaurs in North America" (PDF). GSA Today. 15 (3): 11. doi:10.1130/1052-5173(2005)015<4:TEOTDI>2.0.CO;2. Retrieved 2010-08-21.
  8. ↑ Fastovsky, David E.; Sheehan, Peter M. (2005). "Reply to Comment on 'The Extinction of the Dinosaurs in North America'" (PDF). GSA Today. 15: 11. doi:10.1130/1052-5173(2005)015<11:TEOTDR>2.0.CO;2. Retrieved 2010-08-21.
  9. 1 2 Sloan, Robert E.; Rigby, Keith; Van Valen, Leigh M.; Gabriel, Diane (1986). "Gradual Dinosaur Extinction and Simultaneous Ungulate Radiation in the Hell Creek Formation". Science. 232 (4750): 629–633. Bibcode:1986Sci...232..629S. doi:10.1126/science.232.4750.629. PMID 17781415.
  10. ↑ Lucas, Spencer G. (2000). Dinosaurs: The Textbook (3rd ed.). Boston: McGraw-Hill. p. 237. ISBN 0-07-303642-0.
  11. ↑ Mackal, Roy (1987). A Living Dinosaur?: In Search of Mokele-Mbembe. United States of America: Brill Archive. pp. 3–6 [4]. ISBN 9789004085435.
  12. ↑ "Dinosaurs in Archaeology". Forbidden History. Restoring Genesis. Retrieved July 27, 2013.
  13. ↑ Carroll, Robert T. (1994–2009). "The Skeptic's Dictionary". Retrieved 26 August 2010.
  14. ↑ Shermer, Michael; Linse, Pat (2002). The Skeptic Encyclopedia of Pseudoscience. ABC-CLIO. ISBN 1-57607-653-9.
  15. ↑ H. James Birx (6 January 2009). Encyclopedia of time: science, philosophy, theology, & culture. SAGE. pp. 251–. ISBN 978-1-4129-4164-8. Retrieved 2 September 2011.
  16. ↑ Holtz, Thomas R., Jr. (2007). Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages. New York: Random House. pp. 363–364. ISBN 978-0-375-82419-7.

Further reading

This article is issued from Wikipedia - version of the 8/6/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.