Carpolithes sp.

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 : 72-73

Carpolithes sp. 10

Text-fig. 10a–d

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

PAL 772375.

D e s c r i p t i o n. Elliptic in lateral view, narrowly elliptic in cross section, tapering from the inferred base to the apex, 9.8 mm in length, 7.2 mm by 5.8 mm in widest cross section. Surface largely obscured by adherent sediment forming a rough texture, but missing on one side, revealing a smooth, finely textured surface with a thin longitudinal groove flanked by two low ridges ( Text-fig. 10c ). Base and apex obscured.

D i s c u s s i o n. The adherent sediment likely reflects the mold that enclosed the cast of the original structure which is only partially exposed. The thin groove is suggestive of a point of dehiscence, although it might also be a raphe; the absence of data from both sides of the specimen makes this impossible to decide.

Carpolithes sp. 11 Text fig. 10e–j

M a t e r i a l. Six specimens, chalcedony, including

USNM PAL 772376, 772377.

D e s c r i p t i o n. Items round in face view, a flattened ovoid in lateral view. One face generally broadly convex and flattened, the other often slightly concave to flat with a central or slightly lateral emergent ridge or protuberance. Surface generally smooth. 2.0 to 3.3 mm thick, ranging from 4.4 by 4.8 mm to 6.9 by 5.3 mm in diameter.

D i s c u s s i o n. The repetitive morphology of these structures was distinctive and suggestive of a biological origin, although there is no evidence of possible cellular structure or of distinctive features (e.g., lineations) that would indicate vasculature or dehiscence. While we illustrate one of these examples here as Carpolithes , we suspect they may be abiotic.

Figures

Text-fig. 10. Carpolithes (a–j). a–d: Carpolithes sp. 10. USNM PAL 772375. Scale bar = 5mm, reflected light, palladium coated. a: Lateral view of one face of structure; note adherent mineral material. Longitudinal groove is to right. b: Lateral view of one edge of the structure. c: Opposite view from (b), note groove in upper half of the specimen, facing viewer. d: Apical view. e–j: Carpolithes sp. 11. USNM PAL 772376. Scale bar = 5mm, micro-CT scan surface views. e: Structure in face view showing central protuberance. f: Same, lateral view. g: Opposite face from (e). h: Opposite face from (f). i: View from one end. j: View from opposite end from (i).