Teeth of Embryos in Lamniform Sharks (Chondrichthyes: Elasmobranchii) |
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| Authors: | Kenshu Shimada |
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| Institution: | (1) Environmental Science Program and Department of Biological Sciences, DePaul University, Chicago, IL, 60614, U.S.A.;(2) Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, 60607, U.S.A.;(3) Environmental Science Program, DePaul University, 2320 North Kenmore Avenue, Chicago, IL, 60614, U.S.A. |
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| Abstract: | The dentitions of lamniform sharks possess a unique heterodonty, the lamnoid tooth pattern. However, in embryos, there are 'embryonic' and 'adult' dentitions. The teeth in the embryonic dentition are peg-like and appear to be attached to the jaw in an acrodont fashion. The adult dentition is characterized by the presence of replacement tooth series with the lamnoid tooth pattern. The embryonic–adult transition in dentitions appears at around 30–60 cm TL. Tooth replacement generally begins before birth in embryos with adult dentitions. The adult dentition becomes functional just before or after parturition. An embryo of one species (Lamna nasus) shows a tooth directly on the symphysis of the upper jaws, marking the first record of a medial tooth for the order Lamniformes. |
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| Keywords: | lamnoid dentition dental pattern tooth replacement |
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