Circumpolles

Circumpolles is a gymnosperm pollen type that is important in biostratigraphy and paleoenvironmental reconstruction.^[1] It characterizes the time between the middle Triassic to the middle Cretaceous Periods. This pollen has a unique morphology: it has a circular, equatorial colpus, which divides the pollen grain into two hemispheres. Circumpolles is also unique as it is the only gymnosperm with well developed nexinal columellae.^[2]

Circumpolles Temporal range: Triassic–Cretaceous PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Gymnospermae
Division:	Pinophyta
Class:	Pinopsida
Order:	Pinales
Family:	†Cheirolepidiaceae
Genus:	†Circumpolles

Classopollis were produced by shrubs that tolerated semiarid conditions, and Classopollis is correlated with evaporites and are therefore associated with desert basins, but the shrubs may have also lived in xeric uplands.^[3]