The Schwagerinidae comprise a family of large, generally fusiform, foraminiferans included in the Fusulinacea, a superfamily of fusulinids, locally abundant during the later Carboniferous (Pennsylvanian) and most of the Permian.
M.L. Thompson (1964) gives the following diagnosis: Shell large, fusiform to irregularly cylindrical, planispiral, involute in most, irregularly uncoiled in some; spirotheca thick, composed of tectum and alveolar kariotheca; septa fluted in end zones of primitive genera, fluted completely across shell and to tops of chambers of more advanced genera; tummel singular in most forms, multiple in one genus; axial fillings absent to massive; chomata massive to slight.
As with all fusulinaceans, the Schagerinidae are a shallow water form which in places make up a significant portion of the sediment, now limestone. More familiar genera include Schwagerina, Triticites, and Parafusulina.
. Alfred R. Loeblich Jr . Helen Niña Tappan Loeblich . Alfred R. . Loeblich . Helen . Tappan . Fusulinacea . Protista 2: Sarcodina Chiefly "Thecamoebians" and Foraminiferida . https://books.google.com/books?id=HJSotN7FA-sC . 1964 . Geological Society of America . 978-0-8137-3003-5 . C . 5th . . R.C. . Moore . 415.