Plants: 2–4 cm, light green or yellow-green. Leaves: ovate, concave, 2–3.5 mm; margins entire or nearly so; apex acuminate; costa ending in subula; distal laminal cells hexagonal, 30 µm. Sexual: condition autoicous. Seta: clear pale yellow to stramineous, 1–2 cm. Capsule: not cleistocarpous, clear pale yellow to stramineous, long-ovate; hypophysis often narrower than urn, rarely broader; stomata confined to distal hypophysis; operculum bluntly conic. Calyptra: conic-mitrate or cucullate. Spores: 8 µm, smooth. Phenology: Capsules mature summer.
Caribou or muskox dung. low to high elevations. Greenland, B.C., Nfld. and Labr., N.W.T., Nunavut, Yukon, Alaska, n Europe.
Tetraplodon pallidus and T. paradoxus often grow intermixed and can be distinguished by several characters (W. C. Steere 1977b). Tetraplodon pallidus has a large operculum that falls off exposing a broad, square-shaped mouth and well-developed, reflexed teeth, and its distal laminal cell walls are thin.