Leopecten bakeri diazi (Durham, 1950)
DURHAM, J. W. 1950. Megascopic paleontology and marine stratigraphy. In: 1940 E. W. Scripps Cruise to the Gulf of California, pt. II: Geological Society of America Memoir 43, p. 1-216. [p. 66, pl. 12, fig. 2; pl. 13, fig. 4]
1950 Pecten (Patinopecten) bakeri diazi Durham, 1950
J. W. Durham, 1950, plates 12, 13.
|
«Pecten (Janira) stearnsii Dall var. bakeri Hanna and Hertlein, GRANT AND GALE (in part) (1931), Mem. San Diego Soc. Nat. Hist., vol. 1, p. 224–225, pl. 4, figs. 1a, 1b.
At a number of localities Patinopectens of the P. bakeri stock may be separated from the typical form by the partial or complete obsolescence of the anterior and posterior areas of fine ribbing and by the squarer sides of the major ribs of the left valve. On the same valve, the secondary riblets on the primary ribs are commonly entirely absent or very feeble, and the tertiary intercalaries in the interspaces are missing. In the central areas of the right valve the primary ribs are 1¼ - 1½ times as wide as the interspaces, whereas in the typical form they are approximately of equal width.
Dimensions of holotype: Height 122.8 mm, length 136.3 mm, thickness (approximate, both valves) 21.0 mm. Holotype no. 15968, paratypes nos. 15969, 15970 (loc. A 3566). OCCURRENCE: locs. A 3498, ? A 3505, A 3541, A 3566, ? A 3568; C.A.S. loc. 795; Santa Rosalia (Grant and Gale, 1931, figured specimen). RANGE: middle Pliocene. REMARKS: Ten left valves from loc. A 3566 were available for examination. The smallest is 66 mm, and the largest 136 mm high. Several specimens of both typical bakeri and the new subspecies have both valves associated and show that the left valve is about one-twentieth larger than the right. The specimen figured by Grant and Gale appears to be typical of this subspecies.» JOHN WYATT DURHAM, 1950 |