. The Bashford Dean memorial volume :. Fishes; Sharks; Fishes, Fossil. 672 Bashford Dean Memorial Volume The transition between anterior (cusped) teeth and posterior (grinding) teeth is so gradual that any division into two types must be somewhat arbitrary. However, of the 33 rows of teeth on the upper jaw one might assign 19 rows to the anterior region, leaving 14 (seven on each side) in the posterior region. In the lower jaw there are 32 rows of teeth of which 14 rows may be assigned to the anterior region, leaving 18 (nine on each side) for the posterior region. Thus there seem to be more r
. The Bashford Dean memorial volume :. Fishes; Sharks; Fishes, Fossil. 672 Bashford Dean Memorial Volume The transition between anterior (cusped) teeth and posterior (grinding) teeth is so gradual that any division into two types must be somewhat arbitrary. However, of the 33 rows of teeth on the upper jaw one might assign 19 rows to the anterior region, leaving 14 (seven on each side) in the posterior region. In the lower jaw there are 32 rows of teeth of which 14 rows may be assigned to the anterior region, leaving 18 (nine on each side) for the posterior region. Thus there seem to be more rows. Text-figure 12. Anterior teeth of a young Hetero- dontus phiUipi about 761 mm. ( inches) long: A, from the upper; B, from the lower jaw. After Maclay and Macleay, 1879, Figs. 18a and 18b, p. 24. of anterior (cusped) teeth on the upper jaw than on the lower (as in Striiver's figure). In another specimen Maclay counted 34 rows of teeth on the upper jaw and 31 on the lower. The largest number of rows of teeth noted by Maclay on a lower jaw is not stated, but we infer In Maclay's figures, as in Striiver's, the each; but in Maclay's figure these are more ^j^^j^M f7 ^f %^^^ '^hHb Â¥^ ^ "^Wm ^^^ ' / â¢vj, f\ \ B -sl?^ i ^â -^^^^ m W ." w Text-figure 13. Dentition of a very young (recently hatched) female fieterodontus phillipi about 225 mm. ( inches) long: A, upper jaw; B, lower jaw. After Maclay and Macleay, 1879, Figs. 14 and 15, pi. 24. was 36 on an upper jaw; the largest number that it was less. anterior teeth of the adult have only one cusp blunt as if worn by use. Maclay states that. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Dean, Bashford, 1867-1928; Gudger, E. W. (Eugene Willis), 1866-1956. New York : [American Museum of Natural History],
Size: 1255px × 1991px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1900, booksubjectfishes, booksubjectfishesfossil
