Last week we posted a new fossil. Were you able to figure it out?
This particular picture is of the ant, Nylanderia vetula, caught in Dominican amber. Dominican amber is from the Miocene, currently thought to be about 25 million years old. The fossil ants from Arkansas are a bit different.
In 1974, ants were found in amber collected near Malvern, Arkansas, from the Claiborne formation, which is listed as being from the Eocene, roughly 45 million years ago (give or take 3 million years). According to the Arkansas Geological Survey, the Claiborne is a series of fine sand to silty clay layers, with interspersed layers of lignite. The lignite and amber are clearly indicative of terrestrial environments, although there are some marine sediments within the formation. A number of fossils have been found in the formation, including fish and reptile bones and teeth, leaf impressions, trace fossils, and of course, wood and amber.
The specific ants that have been found were identified as Protrechina carpenteri. These ants are in the group Formicinae, one of the more common ant groups. Interestingly, the Eocene ants were anything but common. Ants during this time shifted from the earlier ants to a more modern collection of species. They were quite diverse, with Phillip Ward reporting that David Archibald claimed some of them were the “size of small hummingbirds”.
Images of our Arkansas fossil ant are hard to find, as in, I couldn’t find a single image. However, if you want to see the real thing, go to the Harvard Museum of Comparative Zoology, where Antweb.org reports it is being held. Yet another Arkansas fossil in the hands of another state.