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Observations on the Developing Rostrum and Rostral Teeth of Sawfish: Pristis perotteti and P. cuspidatus
William A. Miller
Vol. 1974, No. 2 (Jun. 13, 1974), pp. 311-318
Stable URL: http://www.jstor.org/stable/1442525
Page Count: 8
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Radiographic and histological investigations were made on the rostrum and rostral teeth of embryo sawfish (Pristis perotteti and P. cuspidatus: Batoidei). It is possible that the rostral teeth do not arise in an alternate way as do most tooth structures and may indeed not be true teeth. Adult tooth numbers and proportions are established at an early stage. The first formed dentine is a thin layer of orthodentine. The rostrum forms as a cartilage bar, with only two lateral canals, which apparently break up to form the characteristic several tubular structures of the adult fish. Development of the rostrum of the two species is essentially similar.