Sample Page

Developeans^[2] or developayellids^[3] are a group of predatory single-celled eukaryotes. They are classified as the family Developayellaceae^[1] (or Developayellidae in zoological nomenclature), the only family in the order Developayellales^[4] (or Developayellida in zoological nomenclature) which is in turn the sole order in the class Developea,^[5] part of the stramenopiles. All known members consume bacteria as prey, except for the genus Develorapax, which consumes other eukaryotes.^[6]

The first known genus of developayellids, Developayella, was described in 1995. Due to many similarities shared with opalinids and heterokont algae, it was considered a member of the stramenopiles,^[7] a diverse group of protists distinguished by two unequally sized flagella, one of which has tripartite mastigonemes (hair-like structures).^[8]

In 1997, Thomas Cavalier-Smith proposed Developayella as the evolutionary link between pseudofungi and opalinids, and described higher taxon ranks to accommodate this genus: family Developayellaceae, order Developayellales, and class Bigyromonadea, in the stramenopile phylum Bigyra.^[9] The concept of ‘bigyromonad’ was later expanded to include the class Pirsonea, another group of phagotrophic stramenopiles.^[10][11]

In 2016, a second genus Develorapax was described, and the class Developea was created to accommodate both genera.^[12] In 2018, Cavalier-Smith validated the order- and family-level names for this group under zoological nomenclature: Developayellida and Developayellidae, respectively.^[11] The group was further expanded in 2020 and 2022 with the description of four new genera: Mediocremonas,^[13] Develocauda, Develocanicus and Cubaremonas.^[6]