ˈärt ə nˌkrīs noun
( plural artenkrei·se -īzə ; or ar·tenkreis·es -īsə̇z)
Usage: usually capitalized
Etymology: German, literally, cycle of species, from arten (plural of art species, kind, type, nature, from Middle High German) + kreis cycle, circle, from Old High German kreiz; akin to Middle Low German kreit, krēt circle, enclosed dueling space, Old High German krizzōn to scratch in (as letters), krazzōn to scratch — more at article , scratch
: a group of species that replace one another in geographic sequence, presumably trace ultimately to a common ancestral form, and are equivalent as a group to a subgenus