{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T12:32:57Z","timestamp":1791289977056,"version":"4.3.0"},"reference-count":42,"publisher":"American Association for the Advancement of Science (AAAS)","issue":"5531","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Science"],"published-print":{"date-parts":[[2001,8,3]]},"abstract":"<jats:p>Many dinosaurs have enormous and complicated bony nasal apertures. Functional interpretation requires knowledge of the location of the external opening in the skin. Traditionally, the fleshy nostril of dinosaurs has been placed in the back of the bony opening, but studies of extant dinosaur relatives suggest that it is located far forward. Narial blood supply and cavernous tissue corroborate the rostral position in dinosaurs. A rostral nostril was, and remains, a virtually invariant rule of construction among Amniota, which has consequences for (i) nasal airstreaming, and hence various physiological parameters, and (ii) the collection of behaviorally relevant circumoral odorants.<\/jats:p>","DOI":"10.1126\/science.1062681","type":"journal-article","created":{"date-parts":[[2002,7,27]],"date-time":"2002-07-27T09:39:52Z","timestamp":1027762792000},"page":"850-853","source":"Crossref","is-referenced-by-count":55,"title":["Nostril Position in Dinosaurs and Other Vertebrates and Its Significance for Nasal Function"],"prefix":"10.1126","volume":"293","author":[{"given":"Lawrence M.","family":"Witmer","sequence":"first","affiliation":[{"name":"Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA."},{"name":"E-mail:"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"221","reference":[{"key":"e_1_3_1_2_2","first-page":"64","volume":"110","author":"Witmer L. M.","year":"2001","unstructured":"Witmer L. M., Nat. Hist. 110, 64 (2001).","journal-title":"Nat. Hist."},{"key":"e_1_3_1_3_2","unstructured":"___ in Functional Morphology in Vertebrate Paleontology J. J. Thomason Ed. (Cambridge Univ. Press New York 1995) pp. 19\u201333."},{"key":"e_1_3_1_4_2","first-page":"173","volume":"17","author":"___","year":"1997","unstructured":"___, Mem. Soc. Vertebr. Paleontol. J. Vertebr. Paleontol. 17, 173 (1997).","journal-title":"Mem. Soc. Vertebr. Paleontol. J. Vertebr. Paleontol."},{"key":"e_1_3_1_5_2","unstructured":"To enhance its radiodensity the margin of the fleshy nostril was radiolabeled by carefully painting it with latex and then sprinkling barium sulfate on the latex. To solve the superimposition problem encountered with any radiograph (e.g. in a lateral radiograph superimposition of left- and right-sided structures into a single plane) stereoscopic radiographs were made by x-raying each specimen twice at slightly different angles and then viewing the radiographs together with a stereoviewer restoring three-dimensionality. For most specimens dorsal and lateral stereoradiographic sets were obtained. When scoring the extent of the bony nostril any narial fossae on the adjacent premaxilla and maxilla were included because they are functionally part of the narial apparatus."},{"key":"e_1_3_1_6_2","unstructured":"Supplemental material is available at Science Online at www.sciencemag.org\/cgi\/content\/full\/293\/5531\/850\/DC1"},{"key":"e_1_3_1_7_2","unstructured":"The rare exceptions to the pattern of a rostrally positioned fleshy nostril are easily understood. For example the sampled cormorant ( Phalacrocorax ) simply lacked a fleshy nostril altogether (a diving adaptation) and the bony nostril of geckos is so small that the fleshy nostril occupied almost its entire extent. The most significant exception was among monitor lizards ( Varanus ). Whereas some species (e.g. V. komodoensis V. giganteus ) resemble other diapsids in having a rostrally positioned fleshy nostril other species (e.g. V. griseus V. dumerili V. exanthematicus ) have a fleshy nostril located in the middle to caudal half of the much enlarged bony nostril. The modifications of the nasal apparatus resulting in retraction of the fleshy nostril are almost certainly associated with apomorphic elaboration of the chemosensory VNO which is enlarged relative to other lizards (29) and almost unique among squamates lies rostral to the fleshy nostril (30 31); thus the enlarged VNO apparatus essentially diverts the nostril caudally in some varanids. Given the diversity of amniotes one would expect to find additional exceptions particularly in lizards and birds which commonly have derived nasal vestibules. The dearth of exceptions in the face of this diversity emphasizes the fundamental nature of the relationship."},{"key":"e_1_3_1_8_2","first-page":"74A","volume":"19","author":"Sedlmayr J. C.","year":"1999","unstructured":"Sedlmayr J. C., Witmer L. M., J. Vertebr. Paleontol. 19, 74A (1999).","journal-title":"J. Vertebr. Paleontol."},{"key":"e_1_3_1_9_2","unstructured":"S. J. Rehorek A. H. Savitsky L. M. Witmer paper presented at the 2001 Annual Meeting of the American Society of Ichthyology and Herpetology State College PA July 2001."},{"key":"e_1_3_1_10_2","first-page":"85A","volume":"19","author":"Witmer L. M.","year":"1999","unstructured":"Witmer L. M., Sampson S. D., J. Vertebr. Paleontol. 19, 85A (1999).","journal-title":"J. Vertebr. Paleontol."},{"key":"e_1_3_1_11_2","unstructured":"A. d'"},{"key":"e_1_3_1_11_3","first-page":"367","volume":"87","author":"Bellairs A.","year":"1953","unstructured":"Bellairs A., Shute C. C. D., J. Anat. 87, 367 (1953).","journal-title":"J. Anat."},{"key":"e_1_3_1_12_2","doi-asserted-by":"publisher","DOI":"10.1002\/jmor.1052250304"},{"key":"e_1_3_1_13_2","doi-asserted-by":"publisher","DOI":"10.1002\/aja.1000070102"},{"key":"e_1_3_1_14_2","doi-asserted-by":"publisher","DOI":"10.1002\/aja.1000830202"},{"key":"e_1_3_1_15_2","doi-asserted-by":"publisher","DOI":"10.2307\/1440406"},{"key":"e_1_3_1_16_2","unstructured":"T. S. Parsons in Biology of the Reptilia C. Gans T. S. Parsons Eds. (Academic Press New York 1970) vol. 2 pp. 99\u2013191."},{"key":"e_1_3_1_17_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00310349"},{"key":"e_1_3_1_18_2","first-page":"311","volume":"87","author":"Dawes J. D. K.","year":"1953","unstructured":"Dawes J. D. K., Prichard M. M. L., J. Anat. 87, 311 (1953).","journal-title":"J. Anat."},{"key":"e_1_3_1_19_2","unstructured":"Why did anyone ever place the nostril caudally in dinosaurs? All leading early paleontologists regarded the largest dinosaurs (sauropods) as primarily \u201camphibious\u201d (32\u201335). This view was clinched by the discovery in the sauropod Diplodocus of a large caudodorsal nasal opening (36) that was thought to serve as a snorkel allowing the nearly submerged dinosaur to breathe (the dorsal opening in Diplodocus is actually just the caudal portion of the bony nostril and the rostral portion extends far forward as a shallow narial fossa; vascular relationships confirm a rostral nostril). Although sauropods were later interpreted as terrestrial (37) the inferred caudal nostril stuck and somehow was transferred to other dinosaurs. Retracted nasal bones perhaps could be evidence but nasal retraction is common in mammals in association with development of a proboscis and mammals have been studied as extant analogs [e.g. (1 38)]. Despite retraction of the bony nostril the fleshy nostril remains rostrally positioned; moreover some mammals with retracted nasals (e.g. tapirs elephants) enhance the fundamental amniote rostroventral position by extending the fleshy nostril out on a trunk. Thus caudal expansion of the bony nostril apparently is not driven by caudal movement of the fleshy nostril but rather by caudal expansion of the vestibular contents that is the narial apparatus."},{"key":"e_1_3_1_20_2","doi-asserted-by":"publisher","DOI":"10.1159\/000143668"},{"key":"e_1_3_1_21_2","doi-asserted-by":"publisher","DOI":"10.1017\/S0022215100048143"},{"key":"e_1_3_1_22_2","doi-asserted-by":"publisher","DOI":"10.1242\/jeb.113.1.447"},{"key":"e_1_3_1_23_2","doi-asserted-by":"publisher","DOI":"10.1242\/jeb.194.1.329"},{"key":"e_1_3_1_24_2","doi-asserted-by":"crossref","unstructured":"J. A. Ruben in Animals and Temperature I. A. Johnston A. F. Bennett Eds. (Cambridge Univ. Press New York 1996) pp. 347\u2013376.","DOI":"10.1017\/CBO9780511721854.015"},{"key":"e_1_3_1_25_2","doi-asserted-by":"crossref","unstructured":"K. Schmidt-Nielsen Animal Physiology (Cambridge Univ. 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Sci."},{"key":"e_1_3_1_38_2","doi-asserted-by":"publisher","DOI":"10.1038\/229172a0"},{"key":"e_1_3_1_39_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-7998.1999.tb00763.x"},{"key":"e_1_3_1_40_2","first-page":"1","volume":"49","author":"Hatcher J. B.","year":"1907","unstructured":"Hatcher J. B., Marsh O. C., Lull R. S., Monogr. U.S. Geol. Surv. 49, 1 (1907).","journal-title":"Monogr. U.S. Geol. Surv."},{"key":"e_1_3_1_41_2","unstructured":"I thank S. W Cho and J. C. Sedlmayr for assistance with collecting data on the extant sample and S. D. Sampson for his role in the dinosaur studies. The manuscript was improved by comments provided by C. M. Holliday J. S. McIntosh P. M. O'Connor S. D. Sampson and J. C. Sedlmayr. S. M. Moody K. de Queiroz R. M. Elsey and J. J. Baumel graciously provided some of the extant specimens. Funding was  provided by NSF grants BSR-9112070 and IBN-9601174 and the Ohio University College of Osteopathic Medicine. The images on the cover and in Fig. 3 were skillfully painted by M. W. Skrepnick and W. L. Parsons respectively under the author's direction."}],"container-title":["Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.science.org\/doi\/pdf\/10.1126\/science.1062681","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,1,9]],"date-time":"2024-01-09T22:09:50Z","timestamp":1704838190000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.science.org\/doi\/10.1126\/science.1062681"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2001,8,3]]},"references-count":42,"journal-issue":{"issue":"5531","published-print":{"date-parts":[[2001,8,3]]}},"alternative-id":["10.1126\/science.1062681"],"URL":"https:\/\/doi.org\/10.1126\/science.1062681","relation":{},"ISSN":["0036-8075","1095-9203"],"issn-type":[{"value":"0036-8075","type":"print"},{"value":"1095-9203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2001,8,3]]}}}