Cretaceous fossils illuminate early ant evolution

NANJING, China, May 31 (UPI) -- The evolutionary success of ants is largely attributed to their social behavior. Tracing the eusocial tendencies of early ant species has proven difficult.

However, new ant fossils from the Cretaceous, uncovered by researchers with the Chinese Academy of Sciences, have offered some clarity on the earliest organizing principles.

Models of early ant evolution suggest some of the earliest ants were solitary specialist predators. Like lone hunters today, these ants likely formed small colonies, but they went hunting for food on their own.

Until now, such simulations haven't fit well with fossil discoveries. Most Cretaceous ant fossils reveal a rather generalized morphology among workers and reproductives, as well as evidence suggesting advanced social organization and extensive worker recruitment.

The latest discovery confirms the predictions of the computer models.

Deposits of 99 million-year-old Burmese amber have revealed a new and bizarre-looking species of ant named Ceratomyrmex ellenbergeri. The specimen's unique cephalic horn and large scythe-like mandibles, which protrude above the head, are evidence of a specialized solitary predator -- not a collective worker or social hunter.

Researchers say the findings -- detailed in the journal Current Biology -- expand the documented morphological and ecological diversity of the earliest ant lineages.