Microcaldus

{{Short description|Genus of ultra-small archaea}}{{Speciesbox

| greatgreatgrandparent_authority = Sakai et al. 2023

| greatgrandparent_authority = Sakai et al. 2023

| grandparent_authority = Sakai et al. 2023

| parent_authority = Sakai et al. 2023

| genus = Microcaldus

| species = variisymbioticus

| authority = Sakai et al. 2023

}}

Microcaldus is a monotypic genus of ultra-small archaea. It contains one species, Microcaldus variisymbioticus. It is in the monotypic family Microcaldaceae, monotypic order Microcaldales, monotypic class Microcaldia and monotypic phylum Microcaldota.{{Cite journal |last1=Sakai |first1=Hiroyuki D. |last2=Nur |first2=Naswandi |last3=Kato |first3=Shingo |last4=Yuki |first4=Masahiro |last5=Shimizu |first5=Michiru |last6=Itoh |first6=Takashi |last7=Ohkuma |first7=Moriya |last8=Suwanto |first8=Antonius |last9=Kurosawa |first9=Norio |date=2022-01-18 |title=Insight into the symbiotic lifestyle of DPANN archaea revealed by cultivation and genome analyses |journal=Proceedings of the National Academy of Sciences |volume=119 |issue=3 |pages=e2115449119 |doi=10.1073/pnas.2115449119 |doi-access=free |pmc=8784108 |pmid=35022241|bibcode=2022PNAS..11915449S }}Parte, A.C., Sardà Carbasse, J., Meier-Kolthoff, J.P., Reimer, L.C. and Göker, M. (2020). [https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.004332 List of Prokaryotic names with Standing in Nomenclature (LPSN) moves to the DSMZ]. International Journal of Systematic and Evolutionary Microbiology, 70, 5607-5612; DOI: 10.1099/ijsem.0.004332