The twisted axis and well developed rostrum give Y. ecaudata a distinctive shape. It is a deep shell, height/length ratios varying from 70-79 (mean 75). The hinge line is solid, bearing some nine anterior and seven posterior strong teeth.

Yoldiella ecaudata appears to have a wide distribution in waters bordering the antarctic continent. Described from the Bellingshausen Sea (from 80°W to 92°W) it has been recorded subsequently from Gauss Station (90°E) from the Davis Sea and from the Antarctic Peninsula. It proves to be relatively common in the Ross Sea in 362-891 m, with a single record from 2525 m. Outside the Ross Sea its known bathymetric range is 265-500 m.

Bransfield Strait