Fusulinacea

Article By:

Ross, Charles A. Department of Geology, Western Washington University, Bellingham, Washington.

Last reviewed:January 2020

DOI:https://doi.org/10.1036/1097-8542.276900

An extinct superfamily of marine organisms in the phylum Protozoa, order Foraminiferida. Fusulinaceans first appeared late in the Mississippian Period, and in the succeeding 100,000,000 years evolved into more than 125 genera and 6000 species before becoming extinct near the close of the Permian Period. Among protozoans, fusulinaceans became giants, many reaching 0.4 in. (1 cm) in length and some even attaining 4 in. (10 cm) in length. The group is characterized by rapid evolution of distinctive morphological features, which have enabled paleontologists to establish a detailed fusulinacean phylogeny and biostratigraphic zonation. These fossils are widespread in Upper Mississippian, Pennsylvanian, and Permian marine strata in the major Eurasian and American geosynclinal belts and adjacent marine shelves, and have been reported from all continents except Australia and Antarctica, as indicated in Fig. 1.

The content above is only an excerpt.