The oldest horseshoe crab: a new xiphosurid from Late Ordovician konservat- lagerstätten deposits, Manitoba, Canada. 2008. D. M. Rudkin et al. Palaeontology 51: 1–9.
Winnipeg Sun and the home of Neil Young:
The 445 million year old horseshoe crab fossils found near Churchill and in the Grand Rapids Uplands area, are now the oldest of their kind on record, said Graham Young, curator of Geology and Palaeontology at the Manitoba Museum.
"It's great we can find things in Manitoba that are new to Manitoba but also new to the world," he said. The fossilized creatures, which exist in a slightly more evolved state today, have a head shaped like a horseshoe, earning them their name. Modern horseshoe crabs can be up to two feet long, said Young. Although they've evolved, they share characteristics with their early ancestors.
This marks the first time horseshoe crab fossils have been discovered in Manitoba, said Young, adding they date back 100 million years earlier than the previously oldest known ones.