. Bulletins of American paleontology. Jurassic Ammonites of British Columbia: Smith and Tipper 29. Text-figure 30. —Whorl shape cross-sections for species oi Fan- ninoceras. Figures are natural size unless otherwise indicated, a-b. Fanninoceras (CharloiticerasI niaudcnse. n. sp. (a. Paratype GSC 98624, b. Paratype GSC 98619)(both ); c. Fanninoceras {Fan- ninoceras) crassum McLeam, 1930 (GSC 98603); d-e. Fanninoceras (Fanninoceras) fannini McLeam. 1930 (d. Holotype GSC 9054, e. Plesiotype GSC 6495); f. Fanninoceras (Fanninoceras) latum McLeam. 1930 (Type GSC 98610) (); g. Fanninoceras (
. Bulletins of American paleontology. Jurassic Ammonites of British Columbia: Smith and Tipper 29. Text-figure 30. —Whorl shape cross-sections for species oi Fan- ninoceras. Figures are natural size unless otherwise indicated, a-b. Fanninoceras (CharloiticerasI niaudcnse. n. sp. (a. Paratype GSC 98624, b. Paratype GSC 98619)(both ); c. Fanninoceras {Fan- ninoceras) crassum McLeam, 1930 (GSC 98603); d-e. Fanninoceras (Fanninoceras) fannini McLeam. 1930 (d. Holotype GSC 9054, e. Plesiotype GSC 6495); f. Fanninoceras (Fanninoceras) latum McLeam. 1930 (Type GSC 98610) (); g. Fanninoceras (Fanni- noceras) kunae McLeam, 1930 (GSC 98607); h-i. Fanninoceras (Charlolticeras) carteri. n. sp. (h. Holotype GSC 98614, GSC 98618) (both ); j. Fanninoceras (Fanninoceras) carlollense McLeam, 1930 (Holotype GSC 4878). outer whorls are compressed, the umbilical wall un- dercut, the flanks flat and the venter sharp. The low density ribs are coarse, rectiradiate on the flanks and projected onto the venter. Type material.—Fanninoceras kunae var. crassum McLeam, 1932; Holotype: GSC 6496. pi. 9, figs. 1-2 (refigured herein. PI. 4. fig. 2); Paratype: GSC 6517, pi. 9. figs. 3-4 (refigured herein, PI. 4. fig. 1). Material.—Five specimens in calcareous sandstone of the Fannin Formation. Measurements. —See Table 8. Discussion. —When McLeam (1932) established the species F. kunaehe recognized two varieties, a coarsely ribbed form he called F. kunae var. crassum and an evolute, more finely ribbed form called F. kunae var. latum. Not only are these forms morphologically dis- tinct with no apparent intermediates, they have dif- ferent geographic distributions. McLeam's varieties are therefore raised to specific status. F. crassum is one of the more evolute species of Fanninoceras (Text-fig. 29) but, as the name suggests, it is most characterized by the coarseness of its ribbing. Occurrence.—F. crassum is also known from the Ashcroft area (Arthur, 1985) of southern
Size: 2136px × 1170px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorpaleonto, bookcentury1800, bookdecade1890, bookyear1895
