PARASCHWAGERINA

genus of extinct fusulinid foraminiferans (protozoans with a relatively large shell readily preservable in the fossil record), the fossils of which are restricted to marine rocks; the animal probably lived in clear water, far from the shoreline. The various species are excellent index, or guide, fossils for the Early Permian (which occurred from 286 to 258 million years ago) and allow the correlation of sometimes widely separated rock units.