Abstract

The familiar Late Paleozoic microfossil Tubiphytes (Maslov, 1956) is known by two other names: the synonymous Nigriporella (Rigby, 1958) and the now taxonomically valid name Shamovella (Rauser-Cernousova, 1950). Shamovella is typically associated with biohermal and peri-biohermal carbonates. The organism is interpreted as belonging to the binder guild. It is primarily restricted to shallow water environments. It ranges in age from as old as the Mississippian to as young as the Paleocene. Most commonly, the range is recognized as extending from the Pennsylvanian to the middle Cretaceous Albian.

Shamovella is a relatively minor organism in the Pennsylvanian. It is a significant contributor in the Lower Permian Wolfcampian. In association with calcareous inozoan and sphinctozoan sponges in the Permian Basin, Shamovella becomes an important and familiar member of the biohermal consortium in the Early Permian (Leonardian) to Late Permian (Ochoan). In the Leonardian (Parafusulina Zone) of the Finlay Mountains of West Texas, for example, binding and stabilizing Shamovella coexists with baffling and encrusting calcareous sponges, bryozoans, and crinoidal thickets. This consortium displaces the older dominant phylloid algal mounds which had their acme of development between the Middle Pennsylvanian (Desmoinesian) and the Early Permian (Wolfcampian). The uppermost Dorashamian Permian reefs (Skiathos Series) on Skyros Island, Greece, and the Changhsiang Formation in Sichuan, China, are considered to be among the youngest Paleozoic occurrences of the consortium. No biohermal occurrences of any type are recorded in Lower Triassic sediments. Shamovella, along with the calcareous inozoan and sphinctozoan sponges and the newly added scleractinid coral component, redevelop into another consortium in the Middle Triassic. This consortium is a significant to major contributor to Middle Triassic to Late Jurassic bioherms.

Shamovella, as an organism, has been assigned to such divergent taxa as the Porifera, Foraminifera, algal-foraminiferal consortium, Hydrozoa, Cyanobacteria, Microproblematicum, Rhodophycophyta, and Cyanobacterium-Chlorophycophyta consortium. Most workers today would align themselves with placing Shamovella with either the sponges or the algae.