Characterized by a small hemispherical test. Ambulacra with simple primaries; pores in a regular, simple series; nearly every ambulacral primary plate with a tubercle. Ambulacra hourglass-shaped, as they are narrower at the ambitus, while the interambulacrals are extraordinarily widened there, extra IA plates wedging in from the borders. IA plates low, each with a horizontal series of tubercles. No clear distinction between primary and secondary tubercles, no distinct vertical series of tubercles. Apical system unknown. Peristome rather large. Spines unknown.

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Journal Beaufortia

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Engel, H. (1964). On Winkleria maastrichtensis nov. gen. et nov. spec. (Echinoidea, Regularia, Stirodonta, Phymosomina, ? Phymosomatidae) from the Upper-Cretaceous (Md) of Maastricht (Limburg, Netherlands). Beaufortia, 10(126), 207–211.