The origin of ceratopsian horn-cores. American Museum novitates ; no. 1065

dc.contributor.authorBrown, Barnum.en_US
dc.contributor.authorSchlaikjer, Erich Maren, 1905-en_US
dc.date.accessioned2005-10-06T16:18:39Z
dc.date.available2005-10-06T16:18:39Z
dc.date.issued1940en_US
dc.description7 p. : ill. ; 24 cm.en_US
dc.descriptionIncludes bibliographical references (p. 7).en_US
dc.description.abstract"In Protoceratops the pronounced horn-core-like structure formed by the arching of the nasal bones represents the first stage in the development of the ceratopsian nasal horn-core. 2. In all of the earlier ceratopsians the nasal horn-core is formed by upgrowth of the nasal bones. This horn-core probably bore a pair of osseous elements, although these elements are known only in two genera. 3. The distinct nasal horn-core suturally united with the nasal bones, as in Triceratops, is the homologue of the nasal ossicle or ossicles of the earlier ceratopsians. 4. The retrogression of the nasal horn with the enlargement of the osseous element or elements seems definitely associated with the progressive development of the brow horns. 5. The brow horn-cores are formed by outgrowths of the dorsal portions of the postorbital (postfrontal) bones. Definite evidence of this is shown by the condition in Brachyceratops, Monoclonius, Chasmosaurus, Styracosaurus, and the immature Triceratops. This development of brow horn-cores is foreshadowed in Protoceratops. With age, the postorbitals in this genus become proportionately enlarged, pronouncedly arched, and very rugose"--P. 6-7.en_US
dc.format.extent897157 bytes
dc.format.mimetypeapplication/pdf
dc.identifier.urihttp://hdl.handle.net/2246/2234
dc.languageengen_US
dc.language.isoen_US
dc.publisherNew York City : The American Museum of Natural Historyen_US
dc.relation.ispartofseriesAmerican Museum novitates ; no. 1065en_US
dc.subject.lccQL1 .A436 no.1065, 1940en_US
dc.subject.lcshCeratopsidae -- Anatomy.en_US
dc.subject.lcshHorns.en_US
dc.titleThe origin of ceratopsian horn-cores. American Museum novitates ; no. 1065en_US
dc.typetexten_US

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