摘要:

InNephrotus, the odontodes of the dermal bones, which show a columnar arrangement, consist of a dentine differing to some extent from that of the scales and the jaw‐teeth. InColoboduscf.bassanii, the odontodes of the dermal bones tend to form areal odontocomplex‐es, more or less vestigially developed. Based in part on SEM study, a discussion is given of the structure and interpretation of the hypermineralized acrodin and ganoin of actinopterygian teeth. In acrodin, certain canals with an irregular course have previously been taken as the external parts of dentinal tubules. As they closely follow the system of fibre‐bundle‐images in the hard tissue, however, they instead represent “residual spaces”, originally containing collagen fibrils. True dentinal tubules may certainly also exist in acrodin but these have no function, similar to that of collagen, to fulfill in initial stages of mineralization of the hard tissue. Structurally, acrodin shows more resemblance to enameloids such as that of elasmobranch teeth than to ganoin. Evidence is presented which further supports the assumption that the ganoin of actinopterygian teeth is the same hard tissue as that occurring elsewhere in the dermal skeleton. Taxonomic remarks are given on some of the investigat

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1978.tb00613.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY