{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,18]],"date-time":"2026-07-18T18:32:59Z","timestamp":1784399579132,"version":"3.55.0"},"reference-count":41,"publisher":"Wiley","issue":"10","license":[{"start":{"date-parts":[[2021,11,30]],"date-time":"2021-11-30T00:00:00Z","timestamp":1638230400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["anatomypubs.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["The Anatomical Record"],"published-print":{"date-parts":[[2022,10]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>A system\u2010by\u2010system approach dominates morphological and evolutionary study; however, some structures that are better understood within the context of an interface between two systems or traditional units remain less well understood. As part of a larger goal to clarify aspects of skull\u2013neck boundary evolution, we herein describe the morphology and development of the occiput and atlas\u2013axis complex in the crocodylian <jats:italic>Alligator mississippiensis<\/jats:italic>. We apply micro\u2010computed tomography scanning, clearing and double staining, and histological analyses to skull\u2013neck boundary structures at three stages of development (embryonic stage 22, 23, and hatchling). Regions of ossification that could possibly pertain to a postparietal were found adjacent to the parietal bone and supraoccipital; however, these were not deemed convincing and are considered part of the supraoccipital. Within the atlas\u2013axis complex, the proatlas appears as two discrete cartilaginous elements in Stage 22 that ossify together at Stage 23. Posterior to the proatlas, the atlas\u2013axis complex is composed of two centra, each with cervical ribs ventrally and neural arches dorsally that begin ossifying at Stage 23. Histology and clearing and staining of Stages 22 and 23 embryos reveal a discrete atlas intercentrum applied to the ventral part of the occipital condyle of the skull. Posterior to this is a cartilage that appears to be a co\u2010chondrified atlas pleurocentrum, axis intercentrum, and axis pleurocentrum. Ossification of this cartilaginous structure produces discrete atlas inter\u2010 and pleurocentra, as well as a singular axis centrum. Together these data are discussed with reference to clarifying historical discrepancies concerning elements at the crocodylian skull\u2013neck boundary.<\/jats:p>","DOI":"10.1002\/ar.24834","type":"journal-article","created":{"date-parts":[[2021,11,30]],"date-time":"2021-11-30T17:42:45Z","timestamp":1638294165000},"page":"3002-3015","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Anatomy and development of skull\u2013neck boundary structures in the skeleton of the extant crocodylian <i>Alligator mississippiensis<\/i>"],"prefix":"10.1002","volume":"305","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4813-1774","authenticated-orcid":false,"given":"Dana E.","family":"Korneisel","sequence":"first","affiliation":[{"name":"Department of Earth Sciences Carleton University  Ottawa Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rebekah","family":"Vice","sequence":"additional","affiliation":[{"name":"Department of Earth Sciences Carleton University  Ottawa Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hillary C.","family":"Maddin","sequence":"additional","affiliation":[{"name":"Department of Earth Sciences Carleton University  Ottawa Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2021,11,30]]},"reference":[{"key":"e_1_2_7_2_1","doi-asserted-by":"publisher","DOI":"10.2307\/1441081"},{"issue":"3","key":"e_1_2_7_3_1","first-page":"288","article-title":"The proatlas, atlas and axis of the crocodilia","volume":"20","author":"Baur G.","year":"1886","journal-title":"The American Naturalist"},{"key":"e_1_2_7_4_1","first-page":"1","article-title":"The chondrocranium and the development of the skull in recent reptiles","volume":"11","author":"Bellairs A.'. 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