Back
Pentadinium polypodum

Pentadinium polypodum Edwards, 1982

Holotype: Edwards, 1982, pl.3, figs.1-2,4-5,7
Locus typicus: Monroe County, Alabama (loc. 6).
Stratum typicum: Gosport Sand (middle Eocene)
Occurrences: Upper part of Lisbon Formation and Gosport Sand (middle Eocene) and lower part of Moodys Branch Formation (upper Eocene) in Alabama (locs. 1, 2, 5, 6, 8), Castle Hayne Formation (middle Eocene) in North Carolina (loc. 17), Santee Limestone (middle Eocene) subsurface in South Carolina (loc. 16), Piney Point Formation (middle Eocene) subsurface in Virginia (loc. 19), subsurface in Georgia (locs. 11, 12).
Age: Middle Eocene

Original diagnosis: Edwards 1982. p. 113: Pentadinium polypodum
A species of Pentadinium with a smooth to faintly granular surface and tri-cornered gonal processes.

Original description: : Edwards 1982. p. 113-114: Pentadinium polypodum
Cysts subspherical, skolochorate, with smooth endophragm and periphragm; periphragm appressed or, more likely, absent, except at paracingulum and at paraplate margins, where it forms parasutural folds and gonal processes; paratabulation gonyaulacacean 3-4", 5-6"", ?5c, 5""" lp, 1 " " " ", s, may be reduced or incompletely developed; archeopyle precingular, type P (3"" only), operculum free.

Dimensions:
Diameter of entire specimen, average, 80 µm (range 60-96 µm); diameter of endocyst, average 58 µm (range 41-69 µm); 20 specimens measured
Holotype, entire 85 µm, endocyst 56 µm

Remarks:
The length and degree of development of the gonal processes vary considerably. Processes may be short and blunt-tipped to long and flared distally (for example, compare Plate 3, figs. 5 and 6) In occasional specimens, additional short trifurcate processes are developed at the paracingulum; these may suggest paracingular paratabulation.

Affinities/Comparisons:
P. polypodum differs from P. goniferum n. sp. in having a nearly smooth rather than coarsely granular to grano-vermiculate endophragm. It differs from P. Iaticinctum laticinctum in having gonal processes, although transistional forms exist.
Feedback/Report bug