The unique characteristics of this species have served as a pretext to be recognized as the “Martian ant” . It could be said that we are dealing with a living fossil, a species that has hardly changed during the millions of years that it has lived under the leaf litter and jungle trees. Its lineage goes back to the beginning of the evolution of ants, one of the most important insects in the world due to its diversity, abundance and specialization.
Ants have evolved since the Cretaceous to become one of the most diverse and abundant families of animals on our planet. However, much remains to be learned about its origins and early evolution. To this challenge came to add new and rich information a species with peculiarities that make it look like a bug straight out of science fiction.
The “Martian ant”, Martialis heureka , has no eyes, is pale in color and grows between three and five millimeters . These characteristics are related to its underground way of life, a habitat for which it developed these adaptations without losing some physical characteristics of its predecessors, such as the sting that it still retains, a reminder of its evolution from wasps. In addition, this ant differs from those we usually know because of the two pincers it has next to its jaws , which, according to the researchers, it would use to capture its prey.
“This animal may represent a type of ‘relic’ that has retained some of the ancestral morphological characteristics.”
This was pointed out by Christian Rabeling , of the University of Texas, who was lucky enough to find the specimen of a hardworking and sterile female. The discovery took place in 2003 among the leaf litter of the jungle near Manaus , in the Brazilian state of Amazonas . In 1998, two specimens had already been discovered by Manfred Verhaagh , from the Staatliches Museum für Naturkunde in Karlsruhe, a city in southwestern Germany, but they could not be properly examined before they were dissected and ended up breaking.
It was the new encounter, in 2003, that allowed a detailed genetic analysis to be carried out that confirmed the importance of this ant: not only is it a new species, but it is also a new subfamily of ants, Martialinae , a sister lineage to all the ants existing today on our planet . A new subfamily of ants ( Formicidae ) had not been named since 1923.
Ants evolved from wasps more than 120 million years ago and this subfamily would be at the evolutionary base of these insects. The research team published the description in the journal “Proceedings of the National Academy of Sciences” (PNAS) in 2008 and noted that:
“This discovery supports the idea that blind, subterranean predatory ants arise at the dawn of ant evolution.”
This does not mean that all ants were initially subterranean and blind, but they do confirm that these adaptations took place early in evolution and have persisted in this species to this day:
“On the basis of morphological and phylogenetic evidence, we suggest that these specialized subterranean predators are the only surviving representatives of a highly divergent lineage that arose near the dawn of ant diversification and have persisted in ecologically stable environments such as tropical soils. for long periods of time.”
The researchers, led by Rabeling himself, assume that the ancestor of the “Martian ant” was Sphecomyrma , a species known as the missing link between wasps and ants.
They do not rule out the possibility of discovering new species of the same family in humid soils such as those of the Amazon jungle , under the fallen leaves and rotten wood where these animals have their habitat:
“M. heureka is a unique Neotropical representative of an extant basal ant lineage. This discovery suggests a large number of species, possibly of great evolutionary importance, still hidden in the floors of the remaining tropical forests. Nightly litter sampling and underground traps would be promising additions for future biodiversity studies.”
Referencias:
Rabeling, C. et al. 2008. Newly discovered sister lineage sheds light on early ant evolution. PNAS 105, 39, 14913-14917. DOI: 10.1073/pnas.0806187105.
Thompson, A. 2008. Strange ‘Ant from Mars’ Discovered. livescience.com.