Mactromyidae Cox, 1929
Key morphological features: Shells have an elongated dome shape. Due to modern relatives, they are thought to also house chemosymbiotic sulfur-oxidizing bacteria.
MOBILITY: Mobile (burrow)
FEEDING MODE: Suspension Feeder
Cox, L. R. et al. 1969. Bivalvia, in R. C. Moore ed., Treatise on Invertebrate Paleontology, Part N, Mollusca 6, Volume 2. The University of Kansas and Geological Society of America. 1224 pp.