The Ant From Hell: An Extinct Insect
Ants belong to a family of insects ( Formicidae ) that, like bees and wasps, are part of the order Hymenoptera. Of the 22,000 species that have been observed, only about 13,800 have been classified, and today species continue to be found at a dizzying rate. The hell ant, a distant relative of current lineages, is one of the most curious.
Ants have colonized every mass on Earth, with the exception of Antarctica and some remote islands. They are an essential piece of any ecosystem, since they account for up to 25% of the terrestrial biomass of animal origin, control invertebrate pests, promote pollination, serve as food for predators and many other things. Meet one of his relatives with us.
Discovery of the ant from hell
Before launching into the characteristics of these ancestral animals, it is necessary to unravel the phylogenetic mess in which they are found. The term “hell ant” refers to the now extinct subfamily of Hymenoptera called Haidomyrmecinae. Although in the past this taxon was conceived as a minor group, there is now consensus that it is an established subfamily.
This group of ancestral ants has only been described with the discovery of 3 fossil records: one in France, another in Myanmar and another in Canada. In addition, in 2020, the discovery of a fossil of a specimen hunting another Cretaceous invertebrate yielded a lot of new information about its way of life. The research, published in the journal Current Biology , has become well known.
Within this subfamily now disappeared, 9 different genera are described, which encompass a total of 13 species. These are: Aquilomyrmex, Ceratomyrmex, Chonidris, Dhagnathos, Haidomyrmex, Haidomyrmodes, Haidoterminus, Linguamyrmex, and Protoceratomyrmex. Over time, several specimen fossils have been found within these groups.
Physical description and behavior
As we have said, the term “hell ant” includes a total of 13 species of ancestral ants, which present different adaptations to the environment and different characteristics. For this reason, we are going to see below some of the most relevant genera of this subfamily, but separately. Do not miss it.
1. Ceratomyrmex
To date, this genus encompasses a single species ( Ceratomyrmex ellenbergeri ) that has been detected in various fossils in the Asian region, dating from the Cretaceous period. Like all representatives of the subfamily, this hell ant stands out for its highly specialized mouth structures, on a very different plane from current species.
For us to understand each other, today’s carnivorous ants have jaws in a “horizontal” plane. Odontomachus monticola, Odontomachus bauri or Anochetus ghilianii are examples of this. However, specimens of the genus Ceratomyrmex have mouthparts in a “vertical” plane, as if they were abyssal fish.
The workers that have been discovered are 4.5 to 5.9 millimeters long and carry a very different clipeus, which forms a kind of “horn” projected between the two antennas. The jaws are large and it is believed that these were primarily used to hunt large prey, although they could also be used as a defense method to push off predators. Here you can see its holotype.
2. Haidomyrmex
This genus contains 3 different species: Haidomyrmex cerberus, Haidomyrmex scimitarus and Haidomyrmex zigrasi . All of them have been dated to the late Cretaceous and have been found in various fossils from the Asian region, as studies indicate.
The specimens of this genus show a variable size, from 3 to 8 millimeters, and have a fairly soft exoskeleton. The structure of its jaws – scythe-shaped – and its clipeus give a long and lethal appearance to the head, which in turn is accompanied by a pair of very pronounced compound eyes.
The particularities of each species have been described, but queens have been found in some and not in others. Anyway, here you can see the holotype of the genus, in this case of the Haidomyrmex zigrasi species .
3. Linguamyrmex
This genus also includes 3 different species: Linguamyrmex brevicornis, Linguamyrmex rhinocerus and Linguamyrmex vladi. Again, all the fossils found date from the late Cretaceous, in the Asia region. They also have a developed clipeus and upright jaws, indicating that they hunted sizable prey — and head-on.
As in the previous genus, this type of hell ant has a pair of prominent jaws in a vertical plane and curved inward. Its length is such that, with the “closed” structure, they come to touch with the clipeus horn, thereby achieving an infallible holding chamber for prey. Here is its holotype and a detail of its cephalic structures.
Why is your find so important?
The ants from hell are a unique find, as they represent the cephalic structures that the ancestors of the species that inhabit ecosystems today developed in the past. In addition to their description, the new findings have gone so far as to describe how these fascinating Hymenopterans hunted, giving us even more insight into their biology and adaptations.
The curious jaws of this subfamily could have served as a defense method and an attack tool at the same time, since the vertically curved structures provide an excellent gripping mechanism. Let’s hope that more fossils preserved in amber will continue to be discovered, in order to delve even more into the peculiarities of these deadly and fascinating Hymenopterans.
