Pilekiinae Sdzuy, 1955

Adrain, Jonathan M. & Karim, Talia S., 2019, Revision of the Early Ordovician (late Tremadocian; Stairsian) cheirurid trilobite Tesselacauda Ross, with species from the Great Basin, western USA, Zootaxa 4661 (2), pp. 201-255 : 209

Subfamily Pilekiinae Sdzuy, 1955

Discussion. Pilekiinae has generally been conceived of as consisting of early, plesiomorphic species of Cheiruridae which lack the synapomorphies of other subfamilies. Lane, for example (1971, text-figs 10, 12, 13) depicted the taxon on his evolutionary tree diagrams as a basal Tremadocian bar from which other lineages were multiply derived. As such it has been considered a paraphyletic group. There is as yet little insight into its phylogenetic structure, nor that of the family in general. Pilekiinae is used here for convenience, with the understanding that as more Tremadocian (and possibly late Cambrian) taxa are revised and described its phylogeny can be formally explored.