Endohelea is a proposed clade of

eukaryote The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fungi, seaweeds, and many unicellular organisms ...

s that are related to

Archaeplastida The Archaeplastida (or kingdom Plantae '' sensu lato'' "in a broad sense"; pronounced ) are a major group of eukaryotes, comprising the photoautotrophic red algae (Rhodophyta), green algae, land plants, and the minor group glaucophytes. It als ...

and the

SAR supergroup SAR is a highly diverse clade of eukaryotes, often considered a supergroup, that includes stramenopiles (heterokonts), alveolates, and rhizarians. It is a node-based taxon (under the Sar name), including all descendants of the three groups' ...

. They used to be considered

heliozoa Heliozoa, commonly known as sun-animalcules, are microbial eukaryotes (protists) with stiff arms (Pseudopodia#Morphology, axopodia) radiating from their spherical bodies, which are responsible for their common name. The axopodia are microtubule- ...

ns, but phylogenetically they belong to a group of microorganisms known as

Cryptista Cryptista is a clade of alga-like eukaryotes. It is most likely related to Archaeplastida which includes plants and many algae, within the larger group Diaphoretickes. Other characteristic features of cryptophyte mtDNAs include large syntenic ...

Classification

Based on studies done by Cavalier-Smith, Chao & Lewis in 2015, the class contained two orders:

Microhelida ''Microheliella'' () is a monotypic genus of protists containing the sole species ''M. maris'', first described in 2012. It has a variety of unusual morphological characteristics which make its broader classification difficult. These include a ce ...

and Heliomonadida. However, according to a study by Cavalier-Smith, published in 2022, the order Heliomonadida is actually part of

Cercozoa Cercozoa (now synonymised with Filosa) is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead united by phylogeny, molecular phylogenies of rRNA and actin or Ubiqu ...

, and only one species of heliomonad, '' Tetrahelia pterbica'', has been kept in Endohelea as its own order Axomonadida. * Class Endohelea Cavalier-Smith 2012 ** Order

Cavalier-Smith 2011 *** Family Microheliellidae Cavalier-Smith 2011 **** Genus ''

Microheliella ''Microheliella'' () is a monotypic genus of protists containing the sole species ''M. maris'', first described in 2012. It has a variety of unusual morphological characteristics which make its broader classification difficult. These include a ce ...

'' Cavalier-Smith & Chao 2012 ** Order Axomonadida *** Family Tetraheliidae **** Genus '' Tetrahelia'' According to a study by Yazaki et al. published in 2022, ''Microheliella'' is Cryptista's sister taxon.

References

External links

Tree of Life: Hacrobia
Cryptista Cryptista classes Taxa named by Thomas Cavalier-Smith {{Cryptista-stub