{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T10:53:16Z","timestamp":1791283996805,"version":"4.1.0"},"reference-count":57,"publisher":"PeerJ","license":[{"start":{"date-parts":[[2020,9,18]],"date-time":"2020-09-18T00:00:00Z","timestamp":1600387200000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100011483","name":"North Carolina Museum of Natural Sciences","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100011483","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:p>Dietary habits in extinct species cannot be directly observed; thus, in the absence of extraordinary evidence, they must be reconstructed with a combination of morphological proxies. Such proxies often include information on dental organization and function such as tooth formation time and tooth replacement rate. In extinct organisms, tooth formation times and tooth replacement rate are calculated, in part via extrapolation of the space between incremental lines in dental tissues representing daily growth (von Ebner Line Increment Width; VEIW). However, to date, little work has been conducted testing assumptions about the primary data underpinning these calculations, specifically, the potential impact of differential sampling and data extrapolation protocols. To address this, we tested a variety of intradental, intramandibular, and ontogentic sampling effects on calculations of mean VEIW, tooth formation times, and replacement rates using histological sections and CT reconstructions of a growth series of three specimens of the extant archosaurian<jats:italic>Alligator mississippiensis<\/jats:italic>. We find transect position within the tooth and transect orientation with respect to von Ebner lines to have the greatest impact on calculations of mean VEIW\u2014a maximum number of VEIW measurements should be made as near to the central axis (CA) as possible. Measuring in regions away from the central axis can reduce mean VEIW by up to 36%, causing inflated calculations of tooth formation time. We find little demonstrable impact to calculations of mean VEIW from the practice of subsampling along a transect, or from using mean VEIW derived from one portion of the dentition to extrapolate for other regions of the dentition. Subsampling along transects contributes only minor variations in mean VEIW (&lt;12%) that are dwarfed by the standard deviation (SD). Moreover, variation in VEIW with distance from the pulp cavity likely reflects idiosyncratic patterns related to life history, which are difficult to control for; however, we recommend increasing the number of VEIW measured to minimize this effect. Our data reveal only a weak correlation between mean VEIW and body length, suggesting minimal ontogenetic impacts. Finally, we provide a relative SD of mean VEIW for Alligator of 29.94%, which can be used by researchers to create data-driven error bars for tooth formation times and replacement rates in fossil taxa with small sample sizes. We caution that small differences in mean VEIW calculations resulting from non-standardized sampling protocols, especially in a comparative context, will produce inflated error in tooth formation time estimations that intensify with crown height. The same holds true for applications of our relative SD to calculations of tooth formation time in extinct taxa, which produce highly variable maximum and minimum estimates in large-toothed taxa (e.g., 718\u20131,331 days in<jats:italic>Tyrannosaurus<\/jats:italic>).<\/jats:p>","DOI":"10.7717\/peerj.9918","type":"journal-article","created":{"date-parts":[[2020,9,18]],"date-time":"2020-09-18T07:48:27Z","timestamp":1600415307000},"page":"e9918","source":"Crossref","is-referenced-by-count":10,"title":["Sampling impacts the assessment of tooth growth and replacement rates in archosaurs: implications for paleontological studies"],"prefix":"10.7717","volume":"8","author":[{"given":"Jens C.D.","family":"Kosch","sequence":"first","affiliation":[{"name":"Paleontology, North Carolina Museum of Natural Sciences, Raleigh, NC, USA"},{"name":"Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1654-1990","authenticated-orcid":true,"given":"Lindsay E.","family":"Zanno","sequence":"additional","affiliation":[{"name":"Paleontology, North Carolina Museum of Natural Sciences, Raleigh, NC, USA"},{"name":"Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"4443","published-online":{"date-parts":[[2020,9,18]]},"reference":[{"key":"10.7717\/peerj.9918\/ref-1","first-page":"53","article-title":"Buccal tooth development, replacement rate, and microstructure in parksosauridae (Dinosauria: Neornithischia)","volume":"2019","author":"Allison","year":"2019","journal-title":"Journal of Vertebrate Paleontology, Program and Abstracts"},{"issue":"1","key":"10.7717\/peerj.9918\/ref-2","doi-asserted-by":"publisher","first-page":"207","DOI":"10.1146\/annurev-earth-042711-105515","article-title":"Paleobiology of herbivorous dinosaurs","volume":"42","author":"Barrett","year":"2014","journal-title":"Annual Review of Earth and Planetary Sciences"},{"issue":"1","key":"10.7717\/peerj.9918\/ref-3","doi-asserted-by":"publisher","first-page":"15787","DOI":"10.1038\/s41598-017-16056-3","article-title":"Histological evidence for a dynamic dental battery in hadrosaurid dinosaurs","volume":"7","author":"Bramble","year":"2017","journal-title":"Scientific Reports"},{"issue":"1","key":"10.7717\/peerj.9918\/ref-4","doi-asserted-by":"publisher","first-page":"12338","DOI":"10.1038\/srep12338","article-title":"Developmental and evolutionary novelty in the serrated teeth of theropod dinosaurs","volume":"5","author":"Brink","year":"2015","journal-title":"Scientific Reports"},{"issue":"4","key":"10.7717\/peerj.9918\/ref-5","doi-asserted-by":"publisher","first-page":"322","DOI":"10.1111\/joa.12280","article-title":"Tooth counts through growth in diapsid reptiles: implications for interpreting individual and size-related variation in the fossil record","volume":"226","author":"Brown","year":"2015","journal-title":"Journal of Anatomy"},{"key":"10.7717\/peerj.9918\/ref-6","doi-asserted-by":"publisher","first-page":"e4129","DOI":"10.7717\/peerj.4129","article-title":"Incremental growth of therizinosaurian dental tissues: implications for dietary transitions in Theropoda","volume":"5","author":"Button","year":"2017","journal-title":"PeerJ"},{"issue":"2","key":"10.7717\/peerj.9918\/ref-7","doi-asserted-by":"publisher","first-page":"235","DOI":"10.1111\/j.1469-7998.1966.tb03006.x","article-title":"Tooth replacement in the slow worm (Anguis fragilis)","volume":"150","author":"Cooper","year":"1966","journal-title":"Journal of Zoology"},{"issue":"4","key":"10.7717\/peerj.9918\/ref-8","doi-asserted-by":"publisher","first-page":"e6485","DOI":"10.7717\/peerj.6485","article-title":"Quantitative heterodonty in Crocodylia: assessing size and shape across modern and extinct taxa","volume":"7","author":"D\u2019Amore","year":"2019","journal-title":"PeerJ"},{"issue":"4","key":"10.7717\/peerj.9918\/ref-9","doi-asserted-by":"publisher","first-page":"732","DOI":"10.1002\/ar.24198","article-title":"Redescription of brachiosaurid sauropod dinosaur material from the Upper Jurassic morrison formation, Colorado, USA","volume":"303","author":"D\u2019Emic","year":"2019","journal-title":"Anatomical Record"},{"issue":"11","key":"10.7717\/peerj.9918\/ref-10","doi-asserted-by":"publisher","first-page":"e0224734","DOI":"10.1371\/journal.pone.0224734","article-title":"Evolution of high tooth replacement rates in theropod dinosaurs","volume":"14","author":"D\u2019Emic","year":"2019","journal-title":"PLOS ONE"},{"issue":"7","key":"10.7717\/peerj.9918\/ref-11","doi-asserted-by":"publisher","first-page":"e69235","DOI":"10.1371\/journal.pone.0069235","article-title":"Evolution of high tooth replacement rates in sauropod dinosaurs","volume":"8","author":"D\u2019Emic","year":"2013","journal-title":"PLOS ONE"},{"issue":"12","key":"10.7717\/peerj.9918\/ref-12","doi-asserted-by":"publisher","first-page":"1009","DOI":"10.1016\/S0003-9969(98)00069-7","article-title":"Comparative observations on the spacing of short-period (von Ebner\u2019s) lines in dentine","volume":"43","author":"Dean","year":"1998","journal-title":"Archives of Oral Biology"},{"issue":"2","key":"10.7717\/peerj.9918\/ref-13","doi-asserted-by":"publisher","first-page":"146","DOI":"10.1002\/jmor.10080","article-title":"Dentition and tooth replacement pattern in Chalcides (Squamata; Scincidae)","volume":"256","author":"Delgado","year":"2003","journal-title":"Journal of Morphology"},{"key":"10.7717\/peerj.9918\/ref-14","first-page":"1","article-title":"Tooth replacement phenomena in lower vertebrates","volume":"52","author":"Edmund","year":"1960","journal-title":"Royal Ontario Museum Life Science Division Contribution"},{"key":"10.7717\/peerj.9918\/ref-15","first-page":"1","article-title":"Sequence and rate of tooth replacement in the crocodilia","volume":"56","author":"Edmund","year":"1962","journal-title":"Royal Ontario Museum Life Sciences Division Contribution"},{"issue":"2","key":"10.7717\/peerj.9918\/ref-16","doi-asserted-by":"publisher","first-page":"155","DOI":"10.1016\/j.jsb.2013.09.018","article-title":"Characterization of crocodile teeth: correlation of composition, microstructure, and hardness","volume":"184","author":"Enax","year":"2013","journal-title":"Journal of Structural Biology"},{"key":"10.7717\/peerj.9918\/ref-17","article-title":"Verification of von Ebner incremental lines in extant and fossil archosaur dentine and tooth replacement rate assessment using counts of von Ebner lines","author":"Erickson","year":"1992"},{"key":"10.7717\/peerj.9918\/ref-18","doi-asserted-by":"publisher","first-page":"189","DOI":"10.1002\/(SICI)1097-4687(199605)228:2<189::AID-JMOR7>3.0.CO;2-0","article-title":"Daily deposition of dentine in juvenile Alligator and assessment of tooth replacement rates using incremental line counts","volume":"228","author":"Erickson","year":"1996a","journal-title":"Journal of Morphology"},{"issue":"25","key":"10.7717\/peerj.9918\/ref-19","doi-asserted-by":"publisher","first-page":"14623","DOI":"10.1073\/pnas.93.25.14623","article-title":"Incremental lines of von Ebner in dinosaurs and the assessment of tooth replacement rates using growth line counts","volume":"93","author":"Erickson","year":"1996b","journal-title":"Proceedings of the National Academy of Sciences"},{"issue":"42","key":"10.7717\/peerj.9918\/ref-20","doi-asserted-by":"publisher","first-page":"675","DOI":"10.1146\/annurev-earth-060313-054858","article-title":"On dinosaur growth","volume":"2014","author":"Erickson","year":"2014","journal-title":"Annual Review of Earth and Planetary Sciences"},{"issue":"3","key":"10.7717\/peerj.9918\/ref-21","doi-asserted-by":"publisher","first-page":"540","DOI":"10.1073\/pnas.1613716114","article-title":"Dinosaur incubation periods directly determined from growth-line counts in embryonic teeth show reptilian-grade development","volume":"114","author":"Erickson","year":"2017","journal-title":"Proceedings of the National Academy of Sciences"},{"issue":"2","key":"10.7717\/peerj.9918\/ref-22","doi-asserted-by":"publisher","first-page":"354","DOI":"10.1671\/0272-4634(2005)025[0354:FDABSO]2.0.CO;2","article-title":"Femoral dimensions and body size of Alligator mississippiensis: estimating the size of extinct Mesoeucrocodylians","volume":"25","author":"Farlow","year":"2005","journal-title":"Journal of Vertebrate Paleontology"},{"key":"10.7717\/peerj.9918\/ref-23","doi-asserted-by":"publisher","first-page":"102","DOI":"10.1016\/j.aquaculture.2019.01.060","article-title":"A pilot study to understand tooth replacement in near-harvest farmed saltwater crocodiles (Crocodylus porosus): implications for blemish induction","volume":"504","author":"Finger","year":"2019","journal-title":"Aquaculture"},{"key":"10.7717\/peerj.9918\/ref-24","doi-asserted-by":"publisher","first-page":"248","DOI":"10.1016\/j.cretres.2015.09.006","article-title":"Histology of teeth and tooth attachment in titanosaurs (Dinosauria; Sauropoda)","volume":"57","author":"Garcia","year":"2016","journal-title":"Cretaceous Research"},{"key":"10.7717\/peerj.9918\/ref-25","article-title":"Biomechanics and the ontogeny of feeding in the american alligator (Alligator Mississippiensis): reconciling factors contributing to intraspecific niche differentiation in a large bodied vertebrate","author":"Gignac","year":"2010"},{"key":"10.7717\/peerj.9918\/ref-26","article-title":"Dental histology of Cretaceous mosasaurs (Reptilia, Squamata): incremental growth lines in dentine and implications for tooth replacement","author":"Gren","year":"2011"},{"issue":"1","key":"10.7717\/peerj.9918\/ref-27","doi-asserted-by":"publisher","first-page":"134","DOI":"10.1017\/S0016756813000526","article-title":"Dental histology of mosasaurs and a marine crocodylian from the Campanian (Upper Cretaceous) of southern Sweden: incremental growth lines and dentine formation rates","volume":"151","author":"Gren","year":"2013","journal-title":"Geological Magazine"},{"issue":"7","key":"10.7717\/peerj.9918\/ref-28","doi-asserted-by":"publisher","first-page":"1210","DOI":"10.1002\/ar.24014","article-title":"Description of tooth ontogeny and replacement patterns in a Juvenile Tarbosaurus baatar (Dinosauria: Theropoda) using CT-scan data","volume":"302","author":"Hanai","year":"2018","journal-title":"Anatomical Record"},{"issue":"143","key":"10.7717\/peerj.9918\/ref-29","doi-asserted-by":"publisher","first-page":"20180039","DOI":"10.1098\/rsif.2018.0039","article-title":"Neutron scanning reveals unexpected complexity in the enamel thickness of an herbivorous Jurassic reptile","volume":"15","author":"Jones","year":"2018","journal-title":"Journal of The Royal Society Interface"},{"issue":"5705","key":"10.7717\/peerj.9918\/ref-30","doi-asserted-by":"publisher","first-page":"635","DOI":"10.1038\/278635a0","article-title":"Growth rings in dinosaur teeth","volume":"278","author":"Johnston","year":"1979","journal-title":"Nature"},{"issue":"2","key":"10.7717\/peerj.9918\/ref-31","doi-asserted-by":"publisher","first-page":"e0172759","DOI":"10.1371\/journal.pone.0172759","article-title":"Exceptionally prolonged tooth formation in elasmosaurid plesiosaurians","volume":"12","author":"Kear","year":"2017","journal-title":"PLOS ONE"},{"issue":"1","key":"10.7717\/peerj.9918\/ref-32","doi-asserted-by":"publisher","first-page":"54","DOI":"10.1006\/eesa.2000.1923","article-title":"Mercury bioconcentration factors in american alligators (Alligator mississippiensis) in the Florida Everglades","volume":"47","author":"Khan","year":"2000","journal-title":"Ecotoxicology and Environmental Safety"},{"issue":"2","key":"10.7717\/peerj.9918\/ref-33","doi-asserted-by":"publisher","first-page":"195","DOI":"10.1002\/jmor.1052180208","article-title":"Heterodonty and patterns of tooth replacement in Crocodylus niloticus","volume":"218","author":"Kieser","year":"1993","journal-title":"Journal of Morphology"},{"key":"10.7717\/peerj.9918\/ref-34","volume-title":"Recording structures of mammals: determination of age and reconstruction of life history","author":"Klevezal","year":"1996"},{"key":"10.7717\/peerj.9918\/ref-35","first-page":"1","article-title":"Bezahnung und Zahnwechsel von Dicraeosaurus hansemanni","author":"Kosch","year":"2010"},{"key":"10.7717\/peerj.9918\/ref-36","article-title":"Tooth replacement and dentition in Giraffatitan brancai","author":"Kosch","year":"2014"},{"key":"10.7717\/peerj.9918\/ref-37","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1525\/california\/9780520273528.003.0004","article-title":"Preparation and sectioning of specimens","volume-title":"Bone Histology of Fossil Tetrapods","author":"Lamm","year":"2013"},{"issue":"3","key":"10.7717\/peerj.9918\/ref-38","doi-asserted-by":"publisher","first-page":"259","DOI":"10.1002\/jmor.1051340302","article-title":"Tooth replacement in the red-backed salamander, Plethodon cinereus","volume":"134","author":"Lawson","year":"1971","journal-title":"Journal of Morhpology"},{"issue":"1","key":"10.7717\/peerj.9918\/ref-39","doi-asserted-by":"publisher","first-page":"152","DOI":"10.1186\/s12862-016-0721-1","article-title":"Ontogeny reveals function and evolution of the hadrosaurid dinosaur dental battery","volume":"16","author":"LeBlanc","year":"2016","journal-title":"BMC Evolutionary Biology"},{"key":"10.7717\/peerj.9918\/ref-40","first-page":"263","volume-title":"The last of the ruling reptiles alligators, crocodiles and their kin","author":"Neill","year":"1971"},{"issue":"5230","key":"10.7717\/peerj.9918\/ref-41","doi-asserted-by":"publisher","first-page":"343","DOI":"10.1038\/225343a0","article-title":"New approach to Zahnreihen","volume":"225","author":"Osborn","year":"1970","journal-title":"Nature"},{"issue":"1","key":"10.7717\/peerj.9918\/ref-42","doi-asserted-by":"publisher","first-page":"180","DOI":"10.1111\/j.1558-5646.1975.tb00825.x","article-title":"Tooth replacement efficiency, patterns and evolution","volume":"29","author":"Osborn","year":"1975","journal-title":"Evolution"},{"issue":"6","key":"10.7717\/peerj.9918\/ref-43","doi-asserted-by":"publisher","first-page":"481","DOI":"10.1016\/0003-9969(95)00002-7","article-title":"Ontogeny of circadian dentinogenesis in the rat incisor","volume":"40","author":"Ohtsuka","year":"1995","journal-title":"Archives of Oral Biology"},{"key":"10.7717\/peerj.9918\/ref-44","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1080\/08912963.2019.1675057","article-title":"Dental histology of three notosuchians (Crocodylomorpha) from the Bauru Group, Upper Cretaceous","volume":"66","author":"Ricart","year":"2019","journal-title":"Historical Biology"},{"key":"10.7717\/peerj.9918\/ref-45","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1002\/9781118498026.ch7","article-title":"Reptilian tooth regeneration","volume-title":"Stem Cells in Craniofacial Development and Regeneration","author":"Richman","year":"2013"},{"issue":"1","key":"10.7717\/peerj.9918\/ref-46","doi-asserted-by":"publisher","first-page":"29","DOI":"10.1007\/BF02408519","article-title":"Rhythmic dentinogenesis in the rabbit incisors: circadian, ultradian & infradian periods","volume":"32","author":"Rosenberg","year":"1980","journal-title":"Calcified Tissue International"},{"key":"10.7717\/peerj.9918\/ref-47","article-title":"Tooth replacement of Euhelopus Zdanskyi [sic!] (Dinosauria: Sauropoda) and the evolution of titanosaurian tooth morphology","author":"Salakka","year":"2014"},{"key":"10.7717\/peerj.9918\/ref-48","article-title":"Tooth replacement of the sauropod dinosaur Tornieria africana (Fraas) from Tendaguru (Late Jurassic, Tanzania)","author":"Sattler","year":"2014"},{"issue":"S1","key":"10.7717\/peerj.9918\/ref-49","doi-asserted-by":"publisher","first-page":"779.8","DOI":"10.1096\/fasebj.30.1_supplement.779.8","article-title":"Ontogeny of enamel thickness in the teeth of Alligator and its significance for crocodyliform dental evolution","volume":"30","author":"Schmiegelow","year":"2016","journal-title":"FASEB Journal"},{"issue":"6","key":"10.7717\/peerj.9918\/ref-50","doi-asserted-by":"publisher","first-page":"e1008134","DOI":"10.1080\/02724634.2015.1008134","article-title":"Dentition and tooth replacement of Dicraeosaurus hansemanni (Dinosauria, Sauropoda, Diplodocoidea) from the Tendaguru Formation of Tanzania","volume":"35","author":"Schwarz","year":"2015","journal-title":"Journal of Vertebrate Paleontology"},{"issue":"3","key":"10.7717\/peerj.9918\/ref-51","doi-asserted-by":"publisher","first-page":"172","DOI":"10.1111\/jzo.12707","article-title":"The significance of enamel thickness in the teeth of Alligator mississippiensis and its diversity among crocodyliforms","volume":"09","author":"Sellers","year":"2019","journal-title":"Journal of Zoology"},{"issue":"11","key":"10.7717\/peerj.9918\/ref-52","doi-asserted-by":"publisher","first-page":"e1230","DOI":"10.1371\/journal.pone.0001230","article-title":"Structural extremes in a cretaceous dinosaur","volume":"2","author":"Sereno","year":"2007","journal-title":"PLOS ONE"},{"key":"10.7717\/peerj.9918\/ref-53","article-title":"Incremental development of primate dental enamel","author":"Smith","year":"2004"},{"key":"10.7717\/peerj.9918\/ref-54","first-page":"195","article-title":"Unusual Tooth Replacement in a New Cenomanian Iguanodontian from the Mussentuchit Member of the Cedar Mountain Formation","volume":"2019","author":"Sokolskyi","year":"2019","journal-title":"Journal of Vertebrate Paleontology, Program and Abstracts"},{"issue":"2","key":"10.7717\/peerj.9918\/ref-55","doi-asserted-by":"publisher","first-page":"66","DOI":"10.1038\/ijos.2013.36","article-title":"Biology of tooth replacement in amniotes","volume":"5","author":"Whitlock","year":"2013","journal-title":"International Journal of Oral Science"},{"issue":"1","key":"10.7717\/peerj.9918\/ref-56","doi-asserted-by":"crossref","first-page":"65","DOI":"10.32800\/abc.2006.29.0065","article-title":"Regression analysis between body and head measurements of Chinese alligators (Alligator sinensis) in captive population","volume":"29","author":"Wu","year":"2006","journal-title":"Animal Biodiversity and Conservation"},{"issue":"22","key":"10.7717\/peerj.9918\/ref-57","doi-asserted-by":"publisher","first-page":"E2009","DOI":"10.1073\/pnas.1213202110","article-title":"Specialized stem cell niche enables repetitive renewal of alligator teeth","volume":"110","author":"Wu","year":"2013","journal-title":"Proceedings of the National Academy of Sciences"}],"container-title":["PeerJ"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/peerj.com\/articles\/9918.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/peerj.com\/articles\/9918.xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/peerj.com\/articles\/9918.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/peerj.com\/articles\/9918.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,7]],"date-time":"2023-10-07T14:19:12Z","timestamp":1696688352000},"score":1,"resource":{"primary":{"URL":"https:\/\/peerj.com\/articles\/9918"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,9,18]]},"references-count":57,"alternative-id":["10.7717\/peerj.9918"],"URL":"https:\/\/doi.org\/10.7717\/peerj.9918","archive":["CLOCKSS","LOCKSS","Portico"],"relation":{},"ISSN":["2167-8359"],"issn-type":[{"value":"2167-8359","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,9,18]]},"article-number":"e9918"}}