An exceptional giant

Eurycercus lamellatus – is a giant flea. Previous phylogenetic analyses placed this species in the Chydoridae – a group of small, spherical water fleas that live mainly on muddy and sandy bottoms or between plants. 

New approaches showed that Eurycercus forms its own family (Eurycercidae) – a sister lineage to the former group. Eurycercus have unique features such as an anatomically distinct postabdomen or many parthenogenetic eggs in the female's brood chamber.