Scientists found evidence in Scotland of a water scorpion that was 5.2 feet long and about 3.2 feet wide. The monster lived about 350 million years ago. Dr. Martin Whyte of Sheffield University discovered tracks of the monster, known as Hibbertopterus, found the tracks in sandstone on a former beach. From the BBC News:
The length of track preserved, 6m (20ft), is remarkable. The stride pattern, too, is huge – 27cm (11in).
Fragmentary fossils of Hibbertopterus are well known from Scottish Lower Carboniferous rocks and were first described from West Lothian in 1831.
The creature did not have the big pincers or carry its tail in the air like the land scorpions we know today, and it did not have a sting, either; but these animal groups are nonetheless distantly related, scientists believe.
What is interesting about this trackway is that is shows Hibbertopterus could move out of its usual water habitat.
“There has been debate about whether it was restricted to water or could come out on land. I believe this trackway shows it could come out for short periods,” explained Dr Whyte.
Link (Thanks, Loren Coleman!)