Development of cyclic shedding teeth from semi-shedding teeth: the inner dental arcade of the stem osteichthyan Lophosteus
The numerous cushion-shaped tooth-bearing plates attributed to the stem group osteichthyan Lophosteus superbus, which are argued here to represent an early form of the osteichthyan inner dental arcade, display a previously unknown and presumably primitive mode of tooth shedding by basal hard tissue...
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| Format: | Article |
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The Royal Society
2017-01-01
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| Series: | Royal Society Open Science |
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| Online Access: | https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.161084 |
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| author | Donglei Chen Henning Blom Sophie Sanchez Paul Tafforeau Tiiu Märss Per E. Ahlberg |
| author_facet | Donglei Chen Henning Blom Sophie Sanchez Paul Tafforeau Tiiu Märss Per E. Ahlberg |
| author_sort | Donglei Chen |
| collection | DOAJ |
| description | The numerous cushion-shaped tooth-bearing plates attributed to the stem group osteichthyan Lophosteus superbus, which are argued here to represent an early form of the osteichthyan inner dental arcade, display a previously unknown and presumably primitive mode of tooth shedding by basal hard tissue resorption. They carry regularly spaced, recumbent, gently recurved teeth arranged in transverse tooth files that diverge towards the lingual margin of the cushion. Three-dimensional reconstruction from propagation phase-contrast synchrotron microtomography (PPC-SRµCT) reveals remnants of the first-generation teeth embedded in the basal plate, a feature never previously observed in any taxon. These teeth were shed by semi-basal resorption with the periphery of their bases retained as dentine rings. The rings are highly overlapped, which evidences tooth shedding prior to adding the next first-generation tooth at the growing edge of the plate. The first generation of teeth is thus diachronous. Successor teeth at the same sites underwent cyclical replacing and shedding through basal resorption, producing stacks of buried resorption surfaces separated by bone of attachment. The number and spatial arrangement of resorption surfaces elucidates that basal resorption of replacement teeth had taken place at the older tooth sites before the addition of the youngest first-generation teeth at the lingual margin. Thus, the replacement tooth buds cannot have been generated by a single permanent dental lamina at the lingual edge of the tooth cushion, but must have arisen either from successional dental laminae associated with the individual predecessor teeth, or directly from the dental epithelium of these teeth. The virtual histological dissection of these Late Silurian microfossils broadens our understanding of the development of the gnathostome dental systems and the acquisition of the osteichthyan-type of tooth replacement. |
| first_indexed | 2024-12-21T06:09:25Z |
| format | Article |
| id | doaj.art-8ecd478891d24f22aba9f5e887950f5c |
| institution | Directory Open Access Journal |
| issn | 2054-5703 |
| language | English |
| last_indexed | 2024-12-21T06:09:25Z |
| publishDate | 2017-01-01 |
| publisher | The Royal Society |
| record_format | Article |
| series | Royal Society Open Science |
| spelling | doaj.art-8ecd478891d24f22aba9f5e887950f5c2022-12-21T19:13:34ZengThe Royal SocietyRoyal Society Open Science2054-57032017-01-014510.1098/rsos.161084161084Development of cyclic shedding teeth from semi-shedding teeth: the inner dental arcade of the stem osteichthyan LophosteusDonglei ChenHenning BlomSophie SanchezPaul TafforeauTiiu MärssPer E. AhlbergThe numerous cushion-shaped tooth-bearing plates attributed to the stem group osteichthyan Lophosteus superbus, which are argued here to represent an early form of the osteichthyan inner dental arcade, display a previously unknown and presumably primitive mode of tooth shedding by basal hard tissue resorption. They carry regularly spaced, recumbent, gently recurved teeth arranged in transverse tooth files that diverge towards the lingual margin of the cushion. Three-dimensional reconstruction from propagation phase-contrast synchrotron microtomography (PPC-SRµCT) reveals remnants of the first-generation teeth embedded in the basal plate, a feature never previously observed in any taxon. These teeth were shed by semi-basal resorption with the periphery of their bases retained as dentine rings. The rings are highly overlapped, which evidences tooth shedding prior to adding the next first-generation tooth at the growing edge of the plate. The first generation of teeth is thus diachronous. Successor teeth at the same sites underwent cyclical replacing and shedding through basal resorption, producing stacks of buried resorption surfaces separated by bone of attachment. The number and spatial arrangement of resorption surfaces elucidates that basal resorption of replacement teeth had taken place at the older tooth sites before the addition of the youngest first-generation teeth at the lingual margin. Thus, the replacement tooth buds cannot have been generated by a single permanent dental lamina at the lingual edge of the tooth cushion, but must have arisen either from successional dental laminae associated with the individual predecessor teeth, or directly from the dental epithelium of these teeth. The virtual histological dissection of these Late Silurian microfossils broadens our understanding of the development of the gnathostome dental systems and the acquisition of the osteichthyan-type of tooth replacement.https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.161084stem osteichthyanstooth replacementinner dental arcadeevolution of gnathostome dentitionthree-dimensional palaeohistologysynchrotron microtomography |
| spellingShingle | Donglei Chen Henning Blom Sophie Sanchez Paul Tafforeau Tiiu Märss Per E. Ahlberg Development of cyclic shedding teeth from semi-shedding teeth: the inner dental arcade of the stem osteichthyan Lophosteus Royal Society Open Science stem osteichthyans tooth replacement inner dental arcade evolution of gnathostome dentition three-dimensional palaeohistology synchrotron microtomography |
| title | Development of cyclic shedding teeth from semi-shedding teeth: the inner dental arcade of the stem osteichthyan Lophosteus |
| title_full | Development of cyclic shedding teeth from semi-shedding teeth: the inner dental arcade of the stem osteichthyan Lophosteus |
| title_fullStr | Development of cyclic shedding teeth from semi-shedding teeth: the inner dental arcade of the stem osteichthyan Lophosteus |
| title_full_unstemmed | Development of cyclic shedding teeth from semi-shedding teeth: the inner dental arcade of the stem osteichthyan Lophosteus |
| title_short | Development of cyclic shedding teeth from semi-shedding teeth: the inner dental arcade of the stem osteichthyan Lophosteus |
| title_sort | development of cyclic shedding teeth from semi shedding teeth the inner dental arcade of the stem osteichthyan lophosteus |
| topic | stem osteichthyans tooth replacement inner dental arcade evolution of gnathostome dentition three-dimensional palaeohistology synchrotron microtomography |
| url | https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.161084 |
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