Lindapecten amenensis (Marks, 1951)
MARKS, J. G. 1951. Miocene stratigraphy and paleontology of western Ecuador. Bulletins of American Paleontology, 33 (139): 277 [7]-432 [162], pls. 43 [1]-51 [9]. [ p. 62 (332), pl. 3 (45), figs. 2, 7]
1951 Pecten (Aequipecten) amenensis Marks, 1951
J. G. Marks, 1951, plate 3 (45).
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«Description (based on holotype and two paratypes).—Shell rather small, moderately convex; valves sub-equal, slightly inequilateral, slightly longer than high. Sculpture of 20 ribs on each valve; ribs rather high, rounded, barely larger than the deep interspaces, ornamented with about six rounded, scaly secondary riblets which do not appear except near ventral margin of shell (probably because of erosion); interspaces with one subdued central riblet; concentric sculpture of closely spaced, subdued lamellae on ribs. Byssal ear with moderately deep notch, wide scar, two closely spaced riblets and three broader riblets, all heavily wrinkled in a sinuous pattern. Right anterior ear and both ears of left valve with eleven fine, wrinkled riblets. Ligament pit of moderate size. Auricular crurae one pair, rather heavy. Ctenolium moderately elongate. Dimensions of holotype, a left valve: length 30.4 mm., height 28.9 mm., convexity 7.5 mm.
Dimensions of paratype, a right valve (figured).— Length (nearly complete) 26.6 mm., height 26.9 mm. convexity 4.5 mm. This species is closely related to P. plurinominis, differing from P. plurinominis and its subspecies mainly by being smaller and having more ribs and weaker secondary sculpture. The lack of secondary sculpture on the earlier part of the shell is probably due to erosion, either chemical or mechanical, during the life of the animal. The only known occurence is at locality I.P.C. 508, near Progreso town, in the upper part of the Progreso formation, Middle Miocene. Material.— Consists of holotype no. 20417 (a left valve) and paratype no. 20418 (left and right valves) in the Paleontological Research Institution.» JAY GLENN MARKS, 1951
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