Zigrasimecia hoelldobleri worker
Zigrasimecia is an
extinct genus of
ants which existed in the
Cretaceous period approximately 98 million years ago. The first specimens were collected from
Burmese amber in
Kachin State, 100 kilometres (62 mi) west of
Myitkyina town in Myanmar. In 2013, palaeoentomologists Phillip Barden and
David Grimaldi published a paper describing and naming
Zigrasimecia tonsora. They described a dealate female with unusual features, notably the highly specialized mandibles. Other features include large ocelli, short scapes, 12 antennomeres, small eyes, and a clypeal margin that has a row of peg-like denticles. The genus
Zigrasimecia was originally
incertae sedis (uncertain placement) within Formicidae until a second species,
Zigrasimecia ferox, was described in 2014, leading to its placement in the subfamily
Sphecomyrminae. Later, it was considered to belong to the distinct subfamily
Zigrasimeciinae.
Due to the highly specialized mandibles, scientists believe that the ants exhibited habits no longer seen in extant ants. The highly movable head suggests that mobility was an important factor for them (probably for feeding behavior), and the rugose projections may have played a major role in nest excavation because the mandibles would have prevented such activity.
Zigrasimecia most likely interacted with the extinct ant genus
Gerontoformica through conflict and probably shared some of their
ecological niches. The mandibles of these ants were probably used for mechanical interactions with food, and they may also have served as traps for potential arthropod prey such as mites and small flies.
Zigrasimecia was possibly a
generalist predator. (
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