Genus Parachasmatopora Morozova & Lavrentjeva, 1981

TYPE SPECIES. — Parachasmatopora maennili Morozova & Lavrentjeva, 1981 by original designation. Sandbian, Ordovician; Estonia.

OCCURRENCE. — Middle-Upper Ordovician; United States, Estonia, Argentina.

DIAGNOSIS. — Reticulated colonies consisting of anastomosing branches. Autozooecia long, having oblong-rectangular shape in deep tangential section, having weakly developed vestibule, arranged in two-three slightly alternating rows on branches. Nodes on low keels present. Cross-section of branches rounded; their dorsal wall thin, carrying thin longitudinal ribs and microacanthostyles.

COMPARISON

Parachasmatopora Morozova & Lavrentjeva, 1981 differs from Chasmatopora Eichwald, 1855 in having 2-3 rows of autozooecia on branches instead of 4 in Chasmatopora .