Prehistoric Malacostraca

Aeger is a genus of fossil prawns. They first occur in the Early Triassic (Paris biota), and died out at the end of the Late Cretaceous. A total of 21 species are known, which makes this the most diverse genus in the family Aegeridae.

Hymenocaris is a genus of Cambrian marine arthropod. The type species, Hymenocaris vermicaudata is known from the Upper Cambrian (Furongian) Ffestiniog Formation, in North Wales, United Kingdom.

The order Pygocephalomorpha is an extinct group of peracarid crustaceans. Pygocephalomorpha appeared in the Late Devonian, were abundant from the Carboniferous era until their extinction in the Early Permian era.

Palaeocarpilius is an extinct genus of crabs belonging to the family Carpiliidae. The type species of this genus is Palaeocarpilius macrocheilus.

Aeschronectida is an extinct order of mantis shrimp-like crustaceans which lived in the Mississippian subperiod in what is now Montana. They exclusively lived in the Carboniferous, or the age of amphibians. They have been found mostly in the U.S. and in the British Isles, in 1979 species were found in the Madera Formation in New Mexico. Aeschronectida was first identified appearing in Continental Europe in around 2014. While sharing similar characteristics to Stomatopoda, they lack certain physical characteristics of that taxon. The first species of Aeschronectida is accredited to Frederick R.

Tealliocaris is an extinct genus of pygocephalomorphans that lived from the Late Devonian to Early Carboniferous periods in Europe and North America. The genus was established in 1908 by Ben Peach, and many species have been assigned to it since, though some are now invalid or have been reassigned to other genera. Although it can be inferred that T. loudonensis was originally intended as the type species of Tealliocaris, this species is now deemed a junior synonym of T. woodwardi, first described as a species of Anthrapalaemon in 1877, and thus T. woodwardi is currently deemed the type species