Venablesia colluvium was a tiny early Eocene beetle only a few millimetres long. Its compact body could close up tightly, with the head tucked beneath a hood-like pronotum and recesses underneath the body for folding the antennae and legs close against the underside. Fully developed hindwings show that the adult was capable of flight.

Comparison with related living beetles suggests that it may have been associated with dead wood and wood-decay fungi. A saproxylic, fungus-associated way of life is therefore plausible, but it is inferred rather than demonstrated directly by the fossil. Most known London Clay specimens are pyritised body fragments, so the protective body construction is better known than the animal’s feeding behaviour.