Grewingkia is an extinct genus of stationary epifaunal suspension feeders
Identification in Hand Sample:
- Solitary rugose coral having a simple, elongate, generally curved corallum
- Septa are numerous; Major septa are long and weakly fused into a narrow axial structure in early stages; the axial structure is broad and spongy in later stages.
- Tabulae are complete or incomplete
- Specimens may reach in excess of 13cm
- The genus Grewingkia Dybowski,1873, on the contrary, mainly includes comparatively large, liberosessile species with strongly dilated septa throughout the early ontogeny, a cardinal fossula often provided with septofossular stage(=short cardinal septum) in the calice, and a tabularium with several peripheral tabellae.
Fossils of Ohio (1996):
- Grewingkia Dybowski is a solitary rugose coral having a simple, elongate, generally curved corallum. Septa are numerous. Major septa are long and weakly fused into a narrow axial structure in early stages; the axial structure is broad and spongy in later stages. Minor septa are of are of variable length. Tabulae are complete or incomplete. A single species of Grewingkia, G.canadensis is present in upper Ordovician strata of southwestern Ohio. It is the largest solitary rugose coral known from those rocks, specimens may reach in excess of 13cm.
Treatise on Invertebrate Paleontology, Part F, 1 of 2 (1981):
- Corallum solitary, trochoid, ceratoid or cylindrical, with convex cardinal side; in early stages septa moderately or strongly dilated, major septa being long and feebly fused into narrow axial structure; in later stages major septa thin and short; axial structure broad, spongy, of numerous mostly irregularly intertwined vermiform septal lobes and lamellae [possibly with synapticulae], may include medial plate; calicular boss present or absent; minor septa projecting variably from moderately wide peripheral stereozone; tabulae complete or incomplete, convex.