Megasurcula yokoyamai is an extinct species of sea snail, a marine gastropod mollusk in the family Pseudomelatomidae, the turrids and allies.Mizunami Sendai City Science Museum: Megasurcula yokoyamai
Distribution Fossils of this marine species have been found in Middle Miocene strata in Japan.
References
Otuka, Y., 1934a: Tertiary structures of the northwestern end of the Kitakami mountainland, Iwate Prefecture, Japan. Bulletin of the Earthquake Research Institute, Tokyo Imperial University, vol. 12, pt. 3, pp. 566–638, pls. 44–51
External links The University Museum, The University of Tokyo : holotype