Aperiploma, Habe, 1952

Carole, Hickman, S. & Ca, 2014, Paleogene marine bivalves of the deep-water Keasey Formation in Oregon, part IV: The anomalodesmatans, PaleoBios 31 (3), pp. 1-21 : 12

Aperiploma ? n. sp.

Figs. 4A–C

Discussion— A large, flat, fragmental specimen 70 mm across preserves distinctive Aperiploma -like concentric undulations in interior nacre with unique reflection and refraction of light as colors that range from gold in some angles of illumination ( Fig. 4A) to green, blue and purple in others ( Fig. 4B,C). Generic assignment is tentative, and formal species description is unwarranted at this time. Illustrations of the nacre may aid in recognition of additional material that might otherwise be overlooked in the field.

Figured specimen —UCMP 110677.

Keasey Formation locality —Upper part of the middle member, Loc.UCMP IP16000. The specimen is embedded in a slab of calcareous siltstone from the upper carbonate layer (UCL of Burns et al. 2005) at the Mist locality and was donated by Casey Burns.