Calculites dispar Varol in Al-Rifaiy et al., 1990
The species of Kahvecia consists of an elliptical base with a surrounding rim, four blocks adorned with pores, and a narrow, solid distal process. In adverse paleoenvironmental conditions, the pores on the segments may become closed due to overgrowth. The two larger blocks align along the length, while the two narrower blocks align along the shorter axis. The morphological and optical properties of Kahvecia dispar align with those observed in the genus Kahvecia.
Al-Rifaiy, I., Varol, O. & Lemone, D. 1990. Middle to late Albian biostratigraphy of the Cuchillo Formation from Sierra de Sapellò, Mexico. Newsletters on Stratigraphy. 21: 187-200.
Varol, O. 2025a. A practical guide to optical studies of calcareous nannofossils. Grzybowski Foundation Special Publication. 29: 1-222
Calculites dispar
Varol in Al-Rifaiy et al., 1990
Middle Albian
Sierra de Sapellõ, Mexico