The main aim of the present study is to examine and describe the small ossicles of Cottiformes from the Baltic Sea, with particular emphasis on their fine surface structures, sculpture and ultrasculpture, at a level of detail that has proven useful in the study of fossil vertebrate microremains.
Shinohara & Imamura 2007), and Wiley & Johnson (2010) most recently classified the former Cottoidei in a separate order Cottiformes. The families Cottidae (possibly not monophyletic; Smith & Wheeler 2004), Cyclopteridae, Liparidae, Psychrolutidae and Agonidae (also possibly not monophyletic), among others, are included within the suborder Cottoidei.