Juxtacribrilina Yang, Seo, Min, Grischenko & Gordon, 2018

Dick, Matthew H., Grischenko, Andrei V., Gordon, Dennis P. & Ostrovsky, Andrew N., 2021, The “ Cribrilina annulata " problem and new species of Juxtacribrilina (Bryozoa Cheilostomata: Cribrilinidae) from the North Pacific, Zootaxa 5016 (3), pp. 333-364 : 336

Genus Juxtacribrilina Yang, Seo, Min, Grischenko & Gordon, 2018

Type species. Cribrilina (Juxtacribrilina) flavomaris Yang, Seo, Min, Grischenko & Gordon, 2018 , by original designation.

Diagnosis. Colony encrusting, multiserial, usually unilaminar except for scattered reduced or dwarf ovicellate zooids overlying basal zooidal layer (limited self-overgrowth by non-ovicellate zooids can occur in J. mutabilis ). Zooids with convex frontal shield of pinnate costae, with intercostal lacunae between adjacent costae; each costa typically with lumen pseudopore at or near tip. Gymnocyst negligible laterally; exposed in proximal corners of zooid or narrowly along proximal margin, or as extended proximal "caudal" zone; frontal pore chambers present or absent on proximal gymnocyst. Non-ovicellate zooids with approximately semicircular secondary orifice and two or more articulated oral spines.Avicularia lacking. Ovicellate zooids occurring in basal layer along with non-ovicellate zooids; as large (including ooecium) as or smaller than latter. Highly reduced dwarf ovicellate zooids occurring frontally, budded from basal or frontal pore chambers; sometimes present in basal layer, budded basally. Ovicell immersed, brood cavity intrazooidal, occupying distal part of ovicellate zooid. Ooecial complex in ovicellate zooids comprising ooecium and pair of modified, non-articulated, latero-oral spines arching over proximal part of ooecium and meeting or fusing at midline. Ooecium reduced to greater or lesser extent, hood-like, cap-like; kenozooidal, budded distally from maternal zooid or from roof of distal pore chamber, with one or more pseudopores; less commonly, ooecium vestigial, narrow, non-kenozooidal, produced as spine-like outgrowth from roof of distal basal pore chamber. Modified latero-oral spines either cylindrical, overlying proximal part of ooecium but not obscuring ooecial proximal edge, or wider and flatter, obscuring ooecial proximal edge; each spine bearing single lumen pseudopore at tip. Ancestrula cribriform, with oral spines, similar to but smaller than subsequent autozooids.

Remarks. Yang et al. (2018) erected Juxtacribrilina as a subgenus in Cribrilina to accommodate four species ( C. annulata , C. corbula , C. mutabilis , and C. flavomaris ) that differed from other species in Cribrilina in having the ooecium reduced in size, lacking avicularia, having modified latero-oral spines associated with the proximal ooecial margin, having dwarf ovicellate zooids, and having only a cribriform ancestrula. The discovery of additional species in Juxtacribrilina , as described herein, shows the existence of a sizeable clade that appears to have radiated independently from Cribrilina , justifying the change in the rank of Juxtacribrilina from subgenus to genus (López- Gappa et al. 2021).