Carpolithes sp. 7

Tiffney, Bruce H. & Manchester, Steven R., 2022, The Early Middle Eocene Wagon Bed Carpoflora Of Central Wyoming, U. S. A., Fossil Imprint 78 (1), pp. 51-79 : 70

Carpolithes sp. 7

Text-fig. 9i–m

M a t e r i a l. One specimen, chalcedony cast, USNM

PAL 772372.

D e s c r i p t i o n. A broken half sphere, 10.9 mm in height and 9.7 mm wide, the thickness (through the broken portion), 5.4 mm. The surface is rough ( Text-fig. 9i ), although it is unclear if this is due to adherent minerals or represents the original condition. One end has a slight constriction suggesting a point of attachment ( Text-fig. 9i, j ); the opposite end is smoothly rounded. In cross section, a palisade layer of a single layer of elongate sclereids is preserved, ranging from 0.5 to 0.85 mm in thickness (Textfig. 9l, m). In places this has peeled off the exterior of the fossil. No further internal structure is present.

D i s c u s s i o n. The palisade layer of cells ( Text-fig. 9l, m ) indicates the botanical nature of this structure. The spherical shape, palisade layer of elongate cells and possible small point of attachment are reminiscent of the drupes of some Lauraceae JUSS. , but the material is not sufficiently well preserved to verify this assignment.

Figures

Text-fig. 9. Carpolithes (a–r). a–d: Carpolithes sp. 5. USNM PAL 772370. Scale bar = 5mm, reflected light, palladium coated. a: Lateral view of seed, apex up, possible raphe descending from apex toward viewer. b: Lateral view of seed, apex up, possible raphe on right. c: Lateral view, opposite side, apex up, possible raphe on left. d: Apical view, note central pit with raphe descending towards bottom margin. e–h: Carpolithes sp. 6. USNM PAL 772371. Scale bar = 5mm. e: Basal view illustrating depression and keel in plane of bisymmetry, reflectedlight, palladium coated. f–h: Micro-CTscansurface rendering.f: Lateralviewshowingrelatively smoothrounded surface. g: Specimen rotated 180° from (f), surface partially eroded. h: Longitudinal view, showing median keel. i–m: Carpolithes sp. 7 USNM PAL 772372. Scale bar = 5mm. i: View of intact face of globose fruit, possible apical constriction at top. j: Lateral view, intact surface to right, possible apical constriction at top, both micro-CT scan surface renderings. k: Apical view. l: Face view illustrating the mineral filling and the fine, radiating structure of the fruit wall on the left and right margins, both reflected light, palladium coated. m: Closeup of the cellular layer on the left of (l), micro-CT scan surface rendering. n–p: Carpolithes sp. 8. USNM PAL 772373. Scale bar = 3mm, reflected light, palladium coated. n: Lateral view of pyrene-like structure, one ridge running vertically in the center of view, the other two forming the left and right margins. o: Lateral view of pyrene-like structure, ridge in (n) on the left. p: End-on view illustrating one convex, one concave, and one relatively flat to very slightly concave face. q, r: Carpolithes sp. 9 USNM PAL 772374. Scale bar = 5mm, reflected light, palladium coated. q: Exterior of the smooth broken half-sphere. r: Interior of the broken half-sphere.