. Fig. 6 Superimposed body outlines of specimens of Stenopterygius quadriscissus (drawn to same size), taken from extremes of the size range (smallest individuals at top). A. From Hauff (1953, pi. 9a), 62 cm long. b. From Hauff (1953, pi. 4c), 115 cm. c. BMNH R4086, 145 cm. d. From Hauff (1953, pi. 5), 200 cm. E. From Hauff (1953, pi. 7a), 230 cm. f. From Hauff (1953, pi. 9b), 304 cm. limits (see p. 6) do not difler greatly from the observed ranges (Fig. 5). /. breviceps is smaller than its latipinnate contemporary /. communis, and also has a smaller size range. Longipinnates tended to be larg
. Fig. 6 Superimposed body outlines of specimens of Stenopterygius quadriscissus (drawn to same size), taken from extremes of the size range (smallest individuals at top). A. From Hauff (1953, pi. 9a), 62 cm long. b. From Hauff (1953, pi. 4c), 115 cm. c. BMNH R4086, 145 cm. d. From Hauff (1953, pi. 5), 200 cm. E. From Hauff (1953, pi. 7a), 230 cm. f. From Hauff (1953, pi. 9b), 304 cm. limits (see p. 6) do not difler greatly from the observed ranges (Fig. 5). /. breviceps is smaller than its latipinnate contemporary /. communis, and also has a smaller size range. Longipinnates tended to be larger than latipinnates (McGowan, 1972b), and although the size range of S. quad- riscissus falls within that of /. communis (Fig. 5), the mean value is higher in the former species (t = 2,592*). CHANGES OCCURING IN THE TAIL AND DORSAL FIN DURING ONTOGENY IN S. quadHscissus The remarkable state of preservation of certain specimens of S. quad- riscissus where the body outline is preserved as a thin carbonaceous film has facilitated observations of ontogenetic changes in the tail and dorsal fin. During development of the tail, the area relative to the precaudal body length increased, and there is some evidence that the angle of the tail bend increased (Table 2). Changes in tail bend angle, however, might simply reflect greater flexibility in younger individuals. Certainly the greatest variation in the angle of the tail bend is seen in the smaller individuals in 13
Size: 3683px × 1357px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookleafnumber17, booksponsorunive, bookyear1973
