are a clear example of sexual dimorphism: males and females differ significantly in their appearance. Both sexes have different ornaments (setation, knobs, and ridges) on their carapace. Other differences are the length of the second antenna, the existence of pleopods in males, and the development of a marsupium (brood pouch) in females. There are generally more females than males, and females are also larger than their male counterparts. Cumaceans are epimorphic, which means that the number of body segments does not change during development. This is a form of incomplete metamorphosis. Females carry the embryos in their marsupium for some time. The larvae leave the marsupium in the manca stage, in which they are almost fully grown and are only missing their last pair of pereiopods. History of research The order Cumacea has been known since 1780, when Ivan Ivanovich Lepechin described the species "Oniscus scorpioides" (now Diastylis scorpioides). At the time, many scientists thought that the cumaceans were larval stages of decapods. In 1846, they were recognised as a separate order by Henrik Nikolaj Krøyer. Twenty-five years later, about fifty different species had been described, and currently there are more than 1,500 described species. The German zoologist Carl Wilhelm Erich Zimmer studied the order Cumacea very intensively. Fossil record The fossil record of cumaceans is very sparse, but extends back into the Mississippian age. Fossil Cumaceans from the early Jurassic scarcely differ from living forms (Bacescu & Petrescu 1999). Eobodotria muisca was found in 2019 in strata from the Middle Cretaceous of Colombia. Exceptional details such as the gut, mouth parts, pereopods, setae bearing uropods, antenna with developed flagella, and even small eyes with ommatidia were preserved. Eobodotria straddles a gap of almost 165 million years in the fossil record of sea commas, providing a reliable calibration point for phylogenetic studies. This species is considered the first certain representative of crown Cumacea. Taxonomy Cumaceans belong to the superorder Peracarida, within the class Malacostraca. The order Cumacea is subdivided into 8 families, 141 genera, and 1,523 species: Bodotriidae Scott, 1901 (379 species in 36 genera) Ceratocumatidae Calman, 1905 (10 species in 2 genera) Diastylidae Bate, 1856 (318 species in 22 genera) Gynodiastylidae Stebbing, 1912 (106 species in 12 genera) Lampropidae Sars, 1878 (114 species in 15 genera) Leuconidae Sars, 1878 (139 species in 16 genera) Nannastacidae Bate, 1866 (426 species in 25 genera) Pseudocumatidae Sars, 1878 (30 species in 12