"'' Candidatus Heimdallarchaeum''" is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

archaea Archaea ( ) is a Domain (biology), domain of organisms. Traditionally, Archaea only included its Prokaryote, prokaryotic members, but this has since been found to be paraphyletic, as eukaryotes are known to have evolved from archaea. Even thou ...

that in turn forms a distinct group within the Promethearchaeati kingdom. Named after the mythical Norse god, Heimdall, one of the sons of

Odin Odin (; from ) is a widely revered god in Norse mythology and Germanic paganism. Most surviving information on Odin comes from Norse mythology, but he figures prominently in the recorded history of Northern Europe. This includes the Roman Em ...

, it is considered the closest relative 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. The first specimens were discovered by a team of

microbiologist A microbiologist (from Greek ) is a scientist who studies microscopic life forms and processes. This includes study of the growth, interactions and characteristics of microscopic organisms such as bacteria, algae, fungi, and some types of par ...

s at the

Uppsala University Uppsala University (UU) () is a public university, public research university in Uppsala, Sweden. Founded in 1477, it is the List of universities in Sweden, oldest university in Sweden and the Nordic countries still in operation. Initially fou ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

from the marine sediments at

Loki's Castle Loki's Castle is a field of five active hydrothermal vents in the Atlantic, mid-Atlantic Ocean, located at 73rd parallel north, 73 degrees north on the Mid-Atlantic Ridge between Iceland and Svalbard at a depth of . When they were discovered in m ...

(

hydrothermal vent Hydrothermal vents are fissures on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hot ...

s in the mid-Atlantic Ocean) and Bay of Aarhus (a waterway in

Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

), and some other species from Auka hydrothermal vent field in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

. Its

class Class, Classes, or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used d ...

, "''Candidatus'' Heimdallarchaeia" is the group of archaea that eukaryotes emerged. A later study reports that their newly developed data shows that the promethearchaeon ancestors of eukaryotes are rooted in a group older than the Heimdallarchaeia. The genus and its family, order and class are not recognized by

LPSN List of Prokaryotic names with Standing in Nomenclature (LPSN) is an online database that maintains information on the naming and taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practi ...

as "pro-correct".

References

Archaea phyla Most recent common ancestors Evolutionary biology {{Archaea-stub