Habitat: it lives on detrital-coarse bottoms, often in the presence of Posidonia oceanica. Distribution: mainly in the eastern basin of the Mediterranean. Common enough.
Notes: this is one of the most common species of the genus Parvicardium in the Mediterranean. Shell oval in form but not much stretched, globose, inequilateral. Its sculpture is made by radial ribs wider than interspaces. Sculpture visible internally too. In the interspaces there are some lamellae dividing some little grooves not much deep. In the two lateral areas (mainly in the posterior one) numerous tubercles are quite visible on ribs, often spiny and prominent ones. Colour pattern is a characteristic of this species: it is made by one spot either dark brown or black in the posterior half of valves.
This species was described as a variety of P exiguum but there are remarkable characters allowing to consider it as a distinct species, such as its small sizes, an outline more roundish, a different sculpture and a different chromatic pattern. A very similar one is P. vroomi that, besides having a larger distribution in the western basin, is more stretched-elliptical in outline (oval in outline as far as scriptum is concerned) and it has a different hinge (Aartsen & Goud, 2000, p. 175). In conclusion from a comparison with P trapezium it is pointed out this last one is smaller in sizes, it is more stretched and ridgy, moreover it has a distribution limited to Cyprus Is. coasts. Average measures of adult specimens are around 3-4 mm in length.