Original Description of Drepanochilus obesus by Sohl, 1967:
- "Shell of medium size, turriculate, with spire and body whorl height almost equal. Pleural angle 32°-33°. Protoconch unknown. Early sculpture of fine spiral ribbons that override very arcuate transverse ribs; at about 1,5 mm whorl height, ribs number 24-28 per whorl and spiral cords average 20 per whorl. Spiral sculpture increases mainly by the addtition of fine spiral threads between the cords. The penultimate whorl usually bears 22-26 cords and threads. Transverse sculpture absent on body whorl. Spiral sculpture of body whorl dominated by two prominent carinations; the posterior carination is strongest and continues to the spikelike termination of the outer lip; 20-24 spiral cords and threads occur on the rounded surface above the posterior carination, 6-8 threads are present on the broadly concave area between the carinations; the steep anterior slope is covered with spiral threads. Growth line strongly opisthocyrt, opisthocline in total. Aperture incompletely known, outer lip expanded to a broad wing that tapers to a slightly curving spike; interior of lip grooved along trend od spiral carination to spikelike termination and ridged along lower two-thirds of extent parallel to edge."
Locus typicus: Red Bird, Niobara County, Wyoming, USA
Stratum typicum: Baculites gregoryensis zone, Red Bird Silty Member, Red Bird Section, Pierre Shale, late Campanian, upper Cretaceous
Measurements: Height: 107+ mm