‘Monstrously Big’ Ants Once Roamed America Biggest-ever US ant fossil unearthed in ancient lake sediments in Wyoming By Rob Quinn, Newser Staff Posted May 4, 2011 7:45 AM CDT 16 comments Comments Titanomyrma lubei is one of the largest ant species ever found; it is the size of a hummingbird. (Bruce Archibald) (Newser) – The fossil of an ant queen the size of a hummingbird has been found in lake sediments in Wyoming. The 2-inch-long ant is the biggest ever found in the US, and the newly identified species is one of the largest to have ever lived, reports LiveScience. Researchers say the "monstrously big ant" lived around 50 million years ago, when Wyoming was a lot warmer. The only ant species of the same size that's still around today lives only in central Africa. New species Titanomyrma lubei is closely related to ants that lived in Europe at around the same time. Scientists believe that there were brief periods tens of millions of years ago when the release of large amounts of methane and carbon dioxide made the Arctic region so warm that an especially intrepid ant could have walked all the way from Europe to North America, or vice versa, over a land bridge. The team that found Titanomyrma has mapped the locations of all giant ant species, past and present, and found that virtually all lived in tropical temperatures, notes the BBC.