Bayerotrochus teramachii, is a species of sea snail, a marine gastropod mollusc in the family Pleurotomariidae.

[1] The shell has a depressed turbinate shape with an apical spire angle of approximately 98 degrees, with inflated body whorls that are exponential in expansion, a clearly impressed suture, and the periphery is rounded and indistinct.

The aperture is oval, the slit is positioned roughly halfway between the periphery and the suture and is relatively long, about 21 percent of the circumference.

The shell is lightly sculptured with numerous spiral cords over 30 above the selenizone (the area where the shell growth filled in the slit) and 17 to 19 spiral cords below the selenizone, crossed by strong axial growth lines which gives the effect of a coarse rectangular pattern.

[2][3] This species has been found at depths of 180 to 500 meters over a large area of the North West Pacific from Japan to the South China Sea, and across to Indonesia and the Philippines.