Curves of tooth size of Recent Squalus mitsukurii
| Length of recent Squalus mitsukurii is up to 110 cm1). A research of the recent S. mitsukurii showed that the size of the anterolateral tooth is 4-5 mm wide in lower jaw and 3-4 mm wide in upper jaw, respectively. No difference is observed between the sexes. Large-sized tooth around 8 mm wide is relatively common in the Miocene deposits in Japan2). Most of the largest size teeth found probably are anterolateral teeth of the lower jaw. By extrapolation of the data of recent S. mitsukurrii to large sized fosssil teeth, the large sized Miocene shark is estimated to be 170-180 cm of total length and is four times as large as that of the recent S. mitsukurii. The spine of the Miocene shark could be 15-16 cm long. |
| 1: FAO Species Catalogue 2: Miocene fossils of the Mizunami group, central Japan 3. Elasmobranchs, 1985 |
A curve of tooth size of Recent Dalatias licha
| The largest recent Dalatias licha reaches up to 160 cm of total length. I examined a recent D. licha of 155 cm in total length. The symphysial tooth of the shark is 17.5 mm long and 8 mm wide. I do not know of such a large tooth in fossil records, though the teeth with nearly equal size are often found. Fossil records of the shark were seen from the Eocene epoch. |
