Who: Arthropleura armata and Arthropleura mammata

What: Giant Millipede

Where: New Mexico, Scotland, Germany, Canada

When: Carboniferous (Late Pennsylvanian)

Arthropleura was one of the largest arthropods to have ever lived. While two species of this animal may have reached up to 2 meters (~6.5 ft) in length during the Paleozoic, It’s living relatives are typically less than 3 millimeters long.