Ellerbeckia frustules are large cylinders with relatively narrow mantles. Cells are joined into filamentous colonies, linked by an interlocking series of ridges and grooves on opposing valve faces. The valve surface is flat and lacks the pores or processes of many centric diatom genera. Two different kinds of valves comprise a colony: linking valves that connect adjacent cells within a colony, and separation valves that occur at the unbroken ends of each colony. In turn, each of these valve types has a cameo form (with ridges) and an intaglio form (with grooves). Internally, unique tube-like processes are present.
Ellerbeckia arenaria grows in subaerial habitats and benthically on sandy sediments of oligotrophic waters. The genus includes species formerly within Melosira and Paralia. Ellerbeckia is also common in Miocene fossil deposits of the western US (Kociolek and Spaulding, 2002).