Tooth-Like Scales in Early Devonian Eugnathostomes and the ‘Outside-In’ Hypothesis for the Origins of Teeth in Vertebrates

Although teeth are considered one of the most important steps in vertebrate evolution, details of their origins are obscure. Two prominent and opposing theories for the evolution of the vertebrate dentition are current: the ‘Outside-in’ hypothesis and the ‘inside-out’ hypothesis. One of the main arg...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of vertebrate paleontology 2011-11, Vol.31 (6), p.1189-1199
Hauptverfasser: Blais, Stephanie A, MacKenzie, Lindsay A, Wilson, Mark V. H
Format: Artikel
Sprache:eng
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
container_end_page 1199
container_issue 6
container_start_page 1189
container_title Journal of vertebrate paleontology
container_volume 31
creator Blais, Stephanie A
MacKenzie, Lindsay A
Wilson, Mark V. H
description Although teeth are considered one of the most important steps in vertebrate evolution, details of their origins are obscure. Two prominent and opposing theories for the evolution of the vertebrate dentition are current: the ‘Outside-in’ hypothesis and the ‘inside-out’ hypothesis. One of the main arguments against the ‘outside-in’ hypothesis is that, although similarities between teeth and scales have been observed, there is little fossil evidence of transitional forms between the two structures. Specimens of ischnacanthid acanthodians from the Man On The Hill (MOTH) locality in the Mackenzie Mountains of Canada provide the first unequivocal example of such transitional forms in an Early Devonian (Lochkovian) vertebrate assemblage. The head scales of these specimens are modified with proximity to the mouth to be extremely tooth-like. Three distinct morphotypes of modified cheek and lip scales are described. Their detailed similarity to teeth suggests that they are a result of the same developmental processes, and also suggests the existence of a field of gene expression near the mouth margin in which scales could be transformed into teeth. These transitional forms remove one of the chief objections to the ‘outside-in’ hypothesis for the origins of teeth in vertebrates.
doi_str_mv 10.1080/039.031.0611
format Article
fullrecord <record><control><sourceid>bioone</sourceid><recordid>TN_cdi_bioone_primary_10_1080_039_031_0611</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>bioone_primary_10_1080_039_031_0611</sourcerecordid><originalsourceid>FETCH-bioone_primary_10_1080_039_031_06113</originalsourceid><addsrcrecordid>eNqVj8FKw0AURQdRMFp3fsCshcQ3mZAma61UKHRh6HaY2pdmNJ0p86ZCNtLP0N_rlzgRf8DF5XLhcOEwdisgE1DBPcg6AykyKIU4Y4mo5TTNK6jPWQL5NE-LUhaX7IroDQCqUhQJ-2ycC126MO_IX151j8SN5TPt-4E_4oezRsd52FodOkfB7SKg7YaHDvnp-LU8BDIbTJ_t6fjN58M-niEZ4q3zv8zSm62xxF3LG8TQje8r9AHXXgekCbtodU9489fX7O5p1jzM07VxzqLae7PTflAC1GioomGMUKOh_Bf8AxPDWMM</addsrcrecordid><sourcetype>Publisher</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype></control><display><type>article</type><title>Tooth-Like Scales in Early Devonian Eugnathostomes and the ‘Outside-In’ Hypothesis for the Origins of Teeth in Vertebrates</title><source>BioOne Complete</source><source>Jstor Complete Legacy</source><creator>Blais, Stephanie A ; MacKenzie, Lindsay A ; Wilson, Mark V. H</creator><creatorcontrib>Blais, Stephanie A ; MacKenzie, Lindsay A ; Wilson, Mark V. H</creatorcontrib><description>Although teeth are considered one of the most important steps in vertebrate evolution, details of their origins are obscure. Two prominent and opposing theories for the evolution of the vertebrate dentition are current: the ‘Outside-in’ hypothesis and the ‘inside-out’ hypothesis. One of the main arguments against the ‘outside-in’ hypothesis is that, although similarities between teeth and scales have been observed, there is little fossil evidence of transitional forms between the two structures. Specimens of ischnacanthid acanthodians from the Man On The Hill (MOTH) locality in the Mackenzie Mountains of Canada provide the first unequivocal example of such transitional forms in an Early Devonian (Lochkovian) vertebrate assemblage. The head scales of these specimens are modified with proximity to the mouth to be extremely tooth-like. Three distinct morphotypes of modified cheek and lip scales are described. Their detailed similarity to teeth suggests that they are a result of the same developmental processes, and also suggests the existence of a field of gene expression near the mouth margin in which scales could be transformed into teeth. These transitional forms remove one of the chief objections to the ‘outside-in’ hypothesis for the origins of teeth in vertebrates.</description><identifier>ISSN: 0272-4634</identifier><identifier>EISSN: 1937-2809</identifier><identifier>DOI: 10.1080/039.031.0611</identifier><language>eng</language><publisher>Society of Vertebrate Paleontology</publisher><ispartof>Journal of vertebrate paleontology, 2011-11, Vol.31 (6), p.1189-1199</ispartof><rights>2011 by the Society of Vertebrate Paleontology</rights><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><linktopdf>$$Uhttps://bioone.org/doi/pdf/10.1080/039.031.0611$$EPDF$$P50$$Gbioone$$H</linktopdf><link.rule.ids>314,776,780,26957,27903,27904,52341</link.rule.ids></links><search><creatorcontrib>Blais, Stephanie A</creatorcontrib><creatorcontrib>MacKenzie, Lindsay A</creatorcontrib><creatorcontrib>Wilson, Mark V. H</creatorcontrib><title>Tooth-Like Scales in Early Devonian Eugnathostomes and the ‘Outside-In’ Hypothesis for the Origins of Teeth in Vertebrates</title><title>Journal of vertebrate paleontology</title><description>Although teeth are considered one of the most important steps in vertebrate evolution, details of their origins are obscure. Two prominent and opposing theories for the evolution of the vertebrate dentition are current: the ‘Outside-in’ hypothesis and the ‘inside-out’ hypothesis. One of the main arguments against the ‘outside-in’ hypothesis is that, although similarities between teeth and scales have been observed, there is little fossil evidence of transitional forms between the two structures. Specimens of ischnacanthid acanthodians from the Man On The Hill (MOTH) locality in the Mackenzie Mountains of Canada provide the first unequivocal example of such transitional forms in an Early Devonian (Lochkovian) vertebrate assemblage. The head scales of these specimens are modified with proximity to the mouth to be extremely tooth-like. Three distinct morphotypes of modified cheek and lip scales are described. Their detailed similarity to teeth suggests that they are a result of the same developmental processes, and also suggests the existence of a field of gene expression near the mouth margin in which scales could be transformed into teeth. These transitional forms remove one of the chief objections to the ‘outside-in’ hypothesis for the origins of teeth in vertebrates.</description><issn>0272-4634</issn><issn>1937-2809</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2011</creationdate><recordtype>article</recordtype><sourceid/><recordid>eNqVj8FKw0AURQdRMFp3fsCshcQ3mZAma61UKHRh6HaY2pdmNJ0p86ZCNtLP0N_rlzgRf8DF5XLhcOEwdisgE1DBPcg6AykyKIU4Y4mo5TTNK6jPWQL5NE-LUhaX7IroDQCqUhQJ-2ycC126MO_IX151j8SN5TPt-4E_4oezRsd52FodOkfB7SKg7YaHDvnp-LU8BDIbTJ_t6fjN58M-niEZ4q3zv8zSm62xxF3LG8TQje8r9AHXXgekCbtodU9489fX7O5p1jzM07VxzqLae7PTflAC1GioomGMUKOh_Bf8AxPDWMM</recordid><startdate>201111</startdate><enddate>201111</enddate><creator>Blais, Stephanie A</creator><creator>MacKenzie, Lindsay A</creator><creator>Wilson, Mark V. H</creator><general>Society of Vertebrate Paleontology</general><scope/></search><sort><creationdate>201111</creationdate><title>Tooth-Like Scales in Early Devonian Eugnathostomes and the ‘Outside-In’ Hypothesis for the Origins of Teeth in Vertebrates</title><author>Blais, Stephanie A ; MacKenzie, Lindsay A ; Wilson, Mark V. H</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-bioone_primary_10_1080_039_031_06113</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2011</creationdate><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Blais, Stephanie A</creatorcontrib><creatorcontrib>MacKenzie, Lindsay A</creatorcontrib><creatorcontrib>Wilson, Mark V. H</creatorcontrib><jtitle>Journal of vertebrate paleontology</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Blais, Stephanie A</au><au>MacKenzie, Lindsay A</au><au>Wilson, Mark V. H</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Tooth-Like Scales in Early Devonian Eugnathostomes and the ‘Outside-In’ Hypothesis for the Origins of Teeth in Vertebrates</atitle><jtitle>Journal of vertebrate paleontology</jtitle><date>2011-11</date><risdate>2011</risdate><volume>31</volume><issue>6</issue><spage>1189</spage><epage>1199</epage><pages>1189-1199</pages><issn>0272-4634</issn><eissn>1937-2809</eissn><abstract>Although teeth are considered one of the most important steps in vertebrate evolution, details of their origins are obscure. Two prominent and opposing theories for the evolution of the vertebrate dentition are current: the ‘Outside-in’ hypothesis and the ‘inside-out’ hypothesis. One of the main arguments against the ‘outside-in’ hypothesis is that, although similarities between teeth and scales have been observed, there is little fossil evidence of transitional forms between the two structures. Specimens of ischnacanthid acanthodians from the Man On The Hill (MOTH) locality in the Mackenzie Mountains of Canada provide the first unequivocal example of such transitional forms in an Early Devonian (Lochkovian) vertebrate assemblage. The head scales of these specimens are modified with proximity to the mouth to be extremely tooth-like. Three distinct morphotypes of modified cheek and lip scales are described. Their detailed similarity to teeth suggests that they are a result of the same developmental processes, and also suggests the existence of a field of gene expression near the mouth margin in which scales could be transformed into teeth. These transitional forms remove one of the chief objections to the ‘outside-in’ hypothesis for the origins of teeth in vertebrates.</abstract><pub>Society of Vertebrate Paleontology</pub><doi>10.1080/039.031.0611</doi><tpages>11</tpages></addata></record>
fulltext fulltext
identifier ISSN: 0272-4634
ispartof Journal of vertebrate paleontology, 2011-11, Vol.31 (6), p.1189-1199
issn 0272-4634
1937-2809
language eng
recordid cdi_bioone_primary_10_1080_039_031_0611
source BioOne Complete; Jstor Complete Legacy
title Tooth-Like Scales in Early Devonian Eugnathostomes and the ‘Outside-In’ Hypothesis for the Origins of Teeth in Vertebrates
url https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-01-25T01%3A15%3A15IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-bioone&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Tooth-Like%20Scales%20in%20Early%20Devonian%20Eugnathostomes%20and%20the%20%E2%80%98Outside-In%E2%80%99%20Hypothesis%20for%20the%20Origins%20of%20Teeth%20in%20Vertebrates&rft.jtitle=Journal%20of%20vertebrate%20paleontology&rft.au=Blais,%20Stephanie%20A&rft.date=2011-11&rft.volume=31&rft.issue=6&rft.spage=1189&rft.epage=1199&rft.pages=1189-1199&rft.issn=0272-4634&rft.eissn=1937-2809&rft_id=info:doi/10.1080/039.031.0611&rft_dat=%3Cbioone%3Ebioone_primary_10_1080_039_031_0611%3C/bioone%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_id=info:pmid/&rfr_iscdi=true