| Ingolfiellida | |
|---|---|
 | |
| Ingolfiella ischitana | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Malacostraca |
| Order: | Ingolfiellida Hansen, 1903 |
| Suborder: | Ingolfiellidea |
| Infraorder: | Ingolfiellidamorpha |
| Families | |
| |
Ingolfiellida is an order of Peracaridan crustaceans, containing one suborder, Ingolfiellidea; both of these are monotypic, containing just one subordinate group. [1] Subordinate to these is infraorder Ingolfiellidamorpha. [2]
The two families, Ingolfiellidae and Metaingolfiellidae, are each considered to belong to their own monotypic parvorders and superfamilies. [3] [2] Over 30 species are known from the two families. [4] These animals are small, vermiform (worm-like) crustaceans that live "in the soft mud of the deep-sea floor, as well as in high mountain freshwater riverbeds, or in subterranean fresh, brackish, and marine interstitial waters of continental ground waters and continental shelves". [5]
This taxon was previously considered a suborder of amphipods, [5] but in 2017 it was deemed distinct enough to be elevated into a separate order. The order's diagnosis noted several diagnostic traits, such as vestigial stalked eyes, the first and second pairs of gnathopods being "eucarpochelate", [a] the pleosome possessing 6 "relatively undifferentiated" segments, a lack of epimera, and reduced pleopods and uropods. [3]
