Haloarcula quadrata

{{Short description|Species of archaeon}}

{{Taxobox

| domain = Archaea

| image = Haloarcula quadrata.png

| image_caption = SEM image of Haloarcula quadrata.

| phylum = Euryarchaeota

| classis = Halobacteria

| ordo = Halobacteriales

| familia = Halobacteriaceae

| genus = Haloarcula

| species = H. quadrata

| binomial = Haloarcula quadrata

| binomial_authority = Oren et al. 1999

}}

Haloarcula quadrata is a species of archaea discovered in a brine pool in the Sinai peninsula of Egypt. It was one of the first strains of prokaryotes whose cells show a flat, box-like shape.{{cite journal|last=Oren|first=A.|author2=Ventosa, A. |author3=Gutierrez, M. C. |author4= Kamekura, M. |title=Haloarcula quadrata sp. nov., a square, motile archaeon isolated from a brine pool in Sinai (Egypt)|journal=International Journal of Systematic Bacteriology|date=1 July 1999|volume=49|issue=3|pages=1149–1155|doi=10.1099/00207713-49-3-1149|pmid=10425773|doi-access=free}}

They were categorized as Haloarcula on the basis of their polar lipid composition.