Monomorium bidentatum is a species of ant

Ant

Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...

 in the subfamily Myrmicinae

Myrmicinae

Myrmicinae is a subfamily of ants. There are about 140 genera within the group, with the family being cosmopolitan. The pupae lack cocoons. Some species retain a functional sting. The petioles of Myrmicinae consist of two nodes...

. It is endemic to two South American countries, Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

 and Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

.

Description

Workers are around 3.5 millimetre (0.137795275590551 in) long. The general color is dark brown, with the mandibles, antennae and legs slightly lighter. Females are almost 4.5 mm (0.177165354330709 in) long, but otherwise very similar to workers.

Distribution

M. bidentatum is found in Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

 and Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

. It was first described from Valdivia, Chile

Valdivia, Chile

Valdivia is a city and commune in southern Chile administered by the Municipality of Valdivia. The city is named after its founder Pedro de Valdivia and is located at the confluence of the Calle-Calle, Valdivia and Cau-Cau Rivers, approximately east of the coastal towns of Corral and Niebla...

.

Taxonomy

The genus Antichthonidris contained only two species, A. bidentata and A. denticulata

Monomorium denticulatum

Monomorium denticulatum is a species of ant in the subfamily Myrmicinae. It is endemic to Argentina. Like M. bidentatum it was first described from Valdivia, Chile.-Description:...

. Both species were originally described by Gustav Mayr

Gustav Mayr

Gustav L. Mayr was an Austrian entomologist and professor in Budapest and Vienna. He specialised in Hymenoptera.- Works :* Formicidae [der Novara-Expedition]. Vienna 1865....

 under genus Monomorium

Monomorium

Monomorium is one of the most species-rich genera of ants, with about 300 species. The most famous is the pharaoh ant, which can be a considerable pest, especially in hospitals. Although most are Old World species, mostly from the African tropics, others are found around the...

. However, Antichthonidris was synonimized with Monomorium in 2001, so that this genus is no longer valid, and the two species are again known under their original name.