In a paper published in the journal Systematic Entomology, researchers described an unusual species of prehistoric trap-jaw ant found in several pieces of Burmese amber (known as burmite).
Photomicrographs of Linguamyrmex vladi. Scale bars – 0.5 mm. Image credit: Barden et al, doi: 10.1111/syen.12253.
The new species is named Linguamyrmex vladi and belongs to the tribe Haidomyrmecini (unicorn or hell ants).
It lived about 98 million years ago during the Cenomanian, the earliest age of the Late Cretaceous epoch.
All studied specimens were mined from the Hukawng Valley in Kachin State, Republic of the Union of Myanmar, formerly known as Burma.
Dr. Phillip Barden, a researcher at the American Museum of Natural History and the New Jersey Institute of Technology, and co-authors probed the burmite pieces using several types of imaging technology, including light microscopes and X-ray micro-computed tomography (micro-CT) scanning.
“Linguamyrmex vladi is distinguished by an unusual suite of morphological characters indicating specialized predatory behavior and an adaptive strategy no longer found among modern ant lineages,” the researchers said.
Photomicrographs of Linguamyrmex vladi and Linguamyrmex sp. Scale bars – 1 mm. Image credit: Barden et al, doi: 10.1111/syen.12253.
The species had oversized, scythe-like mandibles and a horn-like appendage reinforced with metal, the team found.
“Insects are known to sequester metals — in particular, calcium, manganese, zinc, and iron — in ovipositors and mandibles, to increase strength and reduce wear,” they said.
“Scan results indicate that the underside of Linguamyrmex vladi’s clypeal paddle appears to be reinforced, either by greater cuticular density or, more likely, through the incorporation of metals into cuticle.”
Dr. Barden and co-authors believe this fortified ‘horn’ was utilized in tandem with scythe-like mandibles to ‘pin and potentially puncture soft-bodied prey.’
“The mandibles and paddle of Linguamyrmex vladi may have functioned to puncture soft-bodied prey and feed on the hemolymph,” they explained.
“Although this would be a novel strategy, this morphological arrangement is itself entirely novel and it is not at all apparent how these ants could otherwise masticate food items. Although it is obtained from their own larvae, some living ant species do utilize hemolymph as a food source.”
Foragers of Linguamyrmex vladi probably hunted with their mandibles cocked wide open and gaping, quickly snapping shut vertically when the tips of the trigger hairs touched prey, evidently with sufficient force that, were the clypeal paddle not reinforced, it might have been damaged.
Photomicrograph (top) in lateral view of Linguamyrmex sp. and beetle larvae, scale bar – 1.0 mm; and rendering (bottom) of the specimen. Image credit: Barden et al, doi: 10.1111/syen.12253.
“Although it may not be possible to definitively ascertain the behavior of Linguamyrmex vladi, this new species highlights the adaptive diversity of a highly specialized, extinct lineage of Cretaceous, stem-group ants,” the scientists said.
“Just as the diversity and adaptive spectrum of carnivorous theropod dinosaurs could not have been predicted by the study of modern vertebrates alone, the bizarre adaptations of hell ants (indeed, their existence) would remain unknown if not for preservation in amber.”
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Phillip Barden et al. 2017. A New Genus of Hell Ants from the Cretaceous (Hymenoptera: Formicidae: Haidomyrmecini) with A Novel Head Structure. Systematic Entomology 42 (4): 837-846; doi: 10.1111/syen.12253
