Richards Spur

Two specimens of Captorhinus aguti found at Richards Spur

Richards Spur is a Permian fossil locality located at the Dolese Brothers Limestone Quarry north of Lawton, Oklahoma. The locality preserves clay and mudstone fissure fills of a karst system eroded out of Ordovician limestone and dolomite, with the infilling dating to the Artinskian stage of the early Permian (Cisuralian), around 289 to 286 million years ago. Fossils of terrestrial animals are abundant and well-preserved, representing one of the most diverse Paleozoic tetrapod communities known.[1][2] A common historical name for the site is Fort Sill, in reference to the nearby military base.[3] Fossils were first reported at the quarry by workers in 1932, spurring a wave of collecting by local and international geologists. Early taxa of interest included the abundant reptile Captorhinus[4][5] and microsaurs such as Cardiocephalus and Euryodus.[3] Later notable discoveries include Doleserpeton (one of the most lissamphibian-like Paleozoic tetrapods),[6] the most diverse assortment of parareptiles in the Early Permian,[7] and the rare early diapsid Orovenator.[8]

  1. ^ MacDougall, Mark J.; Tabor, Neil J.; Woodhead, Jon; Daoust, Andrew R.; Reisz, Robert R. (2017-06-01). "The unique preservational environment of the Early Permian (Cisuralian) fossiliferous cave deposits of the Richards Spur locality, Oklahoma". Palaeogeography, Palaeoclimatology, Palaeoecology. 475: 1–11. Bibcode:2017PPP...475....1M. doi:10.1016/j.palaeo.2017.02.019. ISSN 0031-0182.
  2. ^ Sullivan, Corwin; Reisz, Robert R.; May, William J. (2000-09-25). "Large dissorophoid skeletal elements from the Lower Permian Richards Spur Fissures, Oklahoma, and their paleoecological implications". Journal of Vertebrate Paleontology. 20 (3): 456–461. doi:10.1671/0272-4634(2000)020[0456:LDSEFT]2.0.CO;2. ISSN 0272-4634. S2CID 140709673.
  3. ^ a b Gregory, J.T.; Peabody, Frank E.; Price, Llewellyn I. (1956). "Revision of the Gymnarthridae: American Permian microsaurs". Yale Peabody Museum Bulletin. 10: 1–77.
  4. ^ Price, L.I. (1935). "Notes on the brain case of Captorhinus". Proceedings of the Boston Society of Natural History. 40 (7): 377–386.
  5. ^ Olson, Everett Claire (29 July 1954). "Fauna of the Vale and Choza; 9. Captorhinomorpha". Fieldiana Geology. 10 (19): 211–218.
  6. ^ Bolt, J. R. (14 November 1969). "Lissamphibian origins: possible protolissamphibian from the Lower Permian of Oklahoma". Science. 166 (3907): 888–891. Bibcode:1969Sci...166..888B. doi:10.1126/science.166.3907.888. ISSN 0036-8075. PMID 17815754. S2CID 10813454.
  7. ^ Macdougall, Mark J.; Scott, Diane; Modesto, Sean P.; Williams, Scott A.; Reisz, Robert R. (2017-07-01). "New material of the reptile Colobomycter pholeter (Parareptilia: Lanthanosuchoidea) and the diversity of reptiles during the Early Permian (Cisuralian)". Zoological Journal of the Linnean Society. 180 (3): 661–671. doi:10.1093/zoolinnean/zlw012. ISSN 0024-4082.
  8. ^ Reisz, Robert R.; et al. (2011). "A new Early Permian reptile and its significance in early diapsid evolution". Proceedings of the Royal Society B. 278 (1725): 3731–3737. doi:10.1098/rspb.2011.0439. PMC 3203498. PMID 21525061.