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This genus is very distinctive and very isolated within the Formicidae. Brown and Kempf described it in 1968. They considered it a very primitive ant and placed it in Myrmicinae, tribe Agroecomyrmecini, together with ants known from Oligocene Baltic amber and Miocene Florissant Shale. It bears superficial resemblance to some extant genera (the "Glamyromyrmex" Pyramica, Ishakidris, Pilotrochus, and Phalacromyrmex) but Brown and Kempf (1968) and Bolton (1984) considered these similarities to be due to convergence. Bolton (2003) raised the tribe to subfamily status, suggesting that Agroecomyrmecinae might be the sister taxon to Myrmicinae. It has since been discovered to be one of the earliest lineages of ants, a clade from the basal polytomy for all ants (Ward 2007).
The name Tatuidris means "armadillo ant," and the specific epithet for the single described species, tatusia, is an old generic name for armadillo (Brown and Kempf 1968), so an appropriate common name is armadillo ants.
Brown and Kempf described a single species, T. tatusia, based on two workers sent to them by Roy Snelling at the Los Angeles County Museum of Natural History. The specimens were from El Salvador, collected in a Berlese sample of humus. Since then published records are few, but Bolton (1984) reported a second collection from Mexico and Fernando Fernandez has reported its occurrence in Colombia (URL). I am sure there are many more records in collections that have simply not made it into any publications or databases yet. With the advent of litter sifting and Winkler extraction as a popular method of ant collecting, Tatuidris are not as rare as they used to seem. Although not very abundant, with frequent litter sifting they can be reliably found in Costa Rican wet forests.
The biology is these ants remains to be observed. I do not know anyone who has seen a live one, and no sexuals are known. The genus is only known as isolated workers found in Winkler or Berlese samples. Tatuidris workers have peculiar mandibular brushes and a powerful sting, which led Brown and Kempf to speculate that Tatuidris might be specialist predators of active or slippery arthropod prey.
In Central America I have observed three distinct pilosity states: abundant long flexuous setae (tatusia), no erect setae, and a dense lanose pubescence. I considered these three species at first, with the first form matching the types. I called the second two forms JTL-001 and JTL-002. Subsequently, CO1 sequences revealed that tatusia and JTL-001 were the same and the variation was intraspecific. I still do not know about JTL-002, because there are no sequence data yet.
The CO1 data do reveal that there is about a 5% sequence divergence between tatusia from Costa Rica and tatusia from Guatemala and southern Mexico.
Literature Cited
Bolton, B. 1984. Diagnosis and relationships of the myrmicine ant genus Ishakidris gen. n. (Hymenoptera: Formicidae). Systematic Entomology 9:373-382.
Bolton, B. 2003. Synopsis and classification of Formicidae. Mem. Amer. Entomol. Inst. 71:1-370.
Brown, W. L., Jr., and W. W. Kempf. 1968 ("1967"). Tatuidris, a remarkable new genus of Formicidae (Hymenoptera). Psyche (Cambridge) 74:183-190.
Ward, P. S. 2007. Phylogeny, classification, and species-level taxonomy of ants (Hymenoptera: Formicidae). Zootaxa 1668:549-563.
Page author: John T. Longino longinoj@evergreen.edu
Date of this version: 10 February 2010.