Named by Carter.

Original description: Test with three or four chambers and a strong apical and antapical spine. Cephalis small, mostly imperforate with a strong triradiate horn; horn single on holotype (pl. KAT16, fig.1) but bifurcating on paratype (pl. KAT16, fig. 4). Thorax and abdomen trapezoidal in outline, usually with small polygonal pore frames, but pore frames sometimes larger. Final post-abdominal chamber strongly inflated composed of large pentagonal and hexagonal pore frames; pore frames reduced in size distally. Final post-abdominal chamber terminating in a short triradiate antapical spine; spine with sharp narrow ridges and wide, deep grooves.

Original remarks: Genus queried because Katroma, as described by Pessagno & Poisson (1981), has an inflated final chamber that terminates in a long open or closed tube. Katroma sinetubus n. sp. differs from all other described species of Katroma in that the distalmost abdominal chamber terminates in a strong antapical spine rather than a terminal tube.

Etymology: Latin, sine tubus without tube; noun.

Katroma sinetubus was named by Gorican et al. (2006). Its type specimen is GSC 111722 and is a 3D body fossil. Its type locality is Rennell Junction, Graham Island; GSC loc. C-080611, which is in a Pliensbachian marine shale in the Ghost Creek Formation of Canada.