Haidomyrmecinae, occasionally called Hell ants, are an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus Genus ( plural genera ) is a taxonomic rank used in the biological classifica ...

of ants (Formicidae) known from

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

fossils found in

amber Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In M ...

s of

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

, and

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

, spanning the late

Albian The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/ Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0 ...

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campani ...

, around 100 to 79 million years ago. The subfamily was first proposed in 2003, but had been subsequently treated as the tribe Haidomyrmecini and placed in the extinct ant subfamily

Sphecomyrminae Sphecomyrminae is an extinct subfamily of ants in family Formicidae known from a series of Cretaceous fossils found in North America, Europe, and Asia. Sphecomyrminae contains eight genera, divided into two tribes Sphecomyrmini and Zigrasim ...

. Reevaluation of Haidomyrmecini in 2020 lead to the elevation of the group back to subfamily. The family contains the nine genera and thirteen species. Members of this family are highly distinct from all other ants, having diverse head ornamentation, and unusually shaped, extended mandibles that articulated vertically rather than horizontally as in modern ants. The jaws in combination with the head ornamentation served to restrain prey, with most species having

seta In biology, setae (singular seta ; from the Latin word for "bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. ...

e (hair-like structures) covering parts of the head which likely functioned as triggers to rapidly close the jaw when disturbed similar to those of modern trap-jaw ants. Fossils indicate that haidomyrmecines were able to take prey solitarily. Like modern ants, they were

eusocial Eusociality (from Greek εὖ ''eu'' "good" and social), the highest level of organization of sociality, is defined by the following characteristics: cooperative brood care (including care of offspring from other individuals), overlapping gen ...

, with distinct worker and queen castes, likely with relatively small colony sizes. Due to their lack of metabolic stores, it is likely that the queens engaged in hunting during the initial foundation of the nest. Haidomymecines are thought to be amongst the most basal and earliest diverging group of ants known.

Genera

up'' Haidomyrmex zigrasi'' Including the type genus '' Haidomyrmex'', the subfamily contains ten genera and fourteen species. The vast majority of species are known from

Burmese amber Burmese amber, also known as Burmite or Kachin amber, is amber from the Hukawng Valley in northern Myanmar. The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period. The ...

, which dates to the mid-Cretaceous, around 100 million years ago. Other species are known from French amber of equivalent age, as well as the Canadian amber of Alberta, Canada, which dates to around 80 million years ago. *'' Aquilomyrmex'' **''A. huangi'' *'' Ceratomyrmex'' **''Ce. ellenbergeri'' *'' Chonidris'' **''Ch. insolita'' *'' Dhagnathos'' **''Dh. autokrator'' *'' Dilobops'' **''Di. bidentata'' *'' Haidomyrmex'' **''Hx. cerberus'' **''Hx. scimitarus'' **''Hx. zigrasi'' *'' Haidomyrmodes'' **''Hs. mammuthus'' *''

Haidoterminus ''Haidoterminus'' is an extinct genus of ant in the Formicidae subfamily Haidomyrmecinae, and is one of only nine genera placed in this subfamily. The genus contains a single described species ''Haidoterminus cippus'' and is known from one La ...

'' **''Ht. cippus'' *'' Linguamyrmex'' **''L. brevicornis'' **''L. rhinocerus'' **''L. vladi'' *'' Protoceratomyrmex'' ** ''P. revelatus''

References

External links

The Reign of the Hell Ants
PBS Eons, Jan 21, 2021 †Haidomyrmecinae Cretaceous insects Fossil ant taxa {{cretaceous-insect-stub