The Echinoid Directory

Phylogeny and classification

Although only one fossil taxon can be assigned to this genus Micropygidae presumably have a long cryptic history. There is a possibility that the Late Jurassic Pedinothuria represents an early member of this clade. Like Micropyga and Kierechinus it has very deep and sharp buccal notches and biserially arranged pore-pairs. However, its pattern of plate compounding is different and it has just a single large primary tubercle on each interambulacral plate that is strongly crenulate. For the present it is left as incertae sedis.

Family Micropygidae Mortensen, 1904

Genus Kierechinus Philip, 1963
Genus Micropyga A. Agassiz, 1879