Bairdops is an extinct genus of mantis shrimp that lived during the Early Carboniferous period in what is now Scotland and the United States. Two named species are currently assigned to it. The type species, B. elegans, has been collected from several Dinantian-aged localities in Scotland, and was first described in 1908 by British geologist Ben Peach as a species of Perimecturus. The generic name was coined decades later in 1979 by American paleontologist Frederick Schram, and honors William Baird. A later species, B. beargulchensis, was named in 1978 after the Serpukhovian-aged Bear Gulch Limestone of Montana where it was discovered. The two species were originally deemed close relatives based on their physical similarities, but several cladistic analyses published since 1998 have suggested the genus may be polyphyletic.

Sculda is an extinct genus of mantis shrimp known from the late Jurassic to late Cretaceous of Germany and Lebanon. Although several species have been assigned to it, some are now deemed dubious or moved to different genera. It was a moderate-sized crustacean, measuring no more than 50 mm (2.0 in) long. Sculda would have lived in a marine environment and been a predatory animal, likely smashing its prey with the widened segment of its raptorial appendages before cutting it with the sharp appendage tips.