Haidomyrmecinae, occasionally called hell ants, are an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

s (Formicidae) known from

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

fossils primarily found in

amber Amber is fossilized tree resin. Examples of it have been appreciated for its color and natural beauty since the Neolithic times, and worked as a gemstone since antiquity."Amber" (2004). In Maxine N. Lurie and Marc Mappen (eds.) ''Encyclopedia ...

from North America, South America, Europe, and Asia, spanning the late

Aptian The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...

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. Campa ...

, around 113 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 Zigrasimeciin ...

. Reevaluation of the Haidomyrmecini in 2020 led to the elevation of the group back to the subfamily. The family contains nine genera and 13 species. Members of this family are highly distinct from all other ants, having diverse head ornamentation, and unusually shaped, extended mandibles that are 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 (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae, ...

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 ( Greek 'good' and social) is the highest level of organization of sociality. It is defined by the following characteristics: cooperative brood care (including care of offspring from other individuals), overlapping generations wit ...

, with distinct worker and queen castes, likely with relatively small colony sizes. Due to their lack of metabolic stores, the queens likely engaged in hunting during the initial foundation of the nest. Haidomyrmecines 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 10 genera and 14 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. Th ...

, 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. Only a single limestone fossil of an hell ant in known so far. It is from the

Crato Formation The Crato Formation is a geologic formation (stratigraphy), formation of Early Cretaceous (Aptian) age in northeastern Brazil's Araripe Basin. It is an important Lagerstätten, Lagerstätte (undisturbed fossil accumulation) for palaeontology, pa ...

of Brazil, from around 113 million years ago, and is considered the oldest ant fossil ever found. *'' 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'' **''Ht. cippus'' *'' Linguamyrmex'' **''L. brevicornis'' **''L. rhinocerus'' **''L. vladi'' *'' Protoceratomyrmex'' ** ''P. revelatus'' *'' Vulcanidris'' **''V. cratensis''

References

External links

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