Pilekiinae Sdzuy, 1955

Adrain, Jonathan M. & Pérez-Peris, Francesc, 2021, Middle Ordovician (Darriwilian) cheirurid trilobites from the Table Cove Formation, western Newfoundland, Canada, Zootaxa 5041 (1), pp. 1-73 : 34

Subfamily Pilekiinae Sdzuy, 1955

Discussion. The pilekiines have often been treated as an independent cheiruroidean family, even in fairly recent work (e.g., Lee and Chatterton [1997, p. 684]; Fortey and Bruton [2013, p. 110]). They have also often been considered an explicit paraphyletic grade ( Lane, 1971, text-figs 10, 12, 13; Chatterton et al., 1990, p. 275; Lee and Chatterton, 1997, p. 685; Adrain and Karim, 2019, p. 209). Essentially, most Tremadocian cheirurid-like species from anywhere in the world have been assigned to the group, along with some younger taxa. Even considered as a paraphyletic grade, the group as presently recognized encompasses a broad range of morphology, with Gondwanan taxa such as Anacheirurus Reed, 1896 , bearing little detailed resemblance to Laurentian taxa such as Pilekia Barton, 1915 , itself. Considerable descriptive and phylogenetic work will be required to meaningfully assess the group, its taxonomic coherency, and relationships between it or its subgroups and younger generally agreed clades of cheirurids. This is beyond the scope of the present work, which is concerned with a single post-Tremadocian new genus. Given the morphological disparity of Pilekiinae and the lack of any obvious synapomorphies that would both define it and indicate it was sister to a phylogenetically separate Cheiruridae , we follow Adrain and Karim (2019) and treat the group for the present as a subfamily of cheirurids.

Peng (1990) introduced a Subfamily Sinoparapilekiinae , which he included with the nominal subfamily in a Family Pilekiidae . Edgecombe et al. (1999) pointed out that Peng’s concept of this taxon was explicitly paraphyletic. They recognized it at tribe level within Pilekiinae , and treated Pilekiinae as a subfamily of Cheiruridae . As outlined by Edgecombe et al. (1999), the potential synapomorphies of Sinoparapilekiini are a suite of characters associated with a posterior eye position, including the presence of pitted fixigena anterior to the eye ridge and an approximately transverse course of the posterior facial suture. We elect for the time being not to recognize Sinoparapilekiini, pending assessment of its monophyly via phylogenetic analysis of the broader pilekiine group.