I came across this when browsing about:
Strange 'Prehistoric' Creature Pulled From Russian Pond Baffles Locals
by Underwatertimes.com News Service - November 14, 2007
CHELYABINSK, Russia -- According to a local report, A strange prehistoric creature has been found in the Russian city of Chelyabinsk. The creature, still unidentified, appeared in a flooded ditch at a construction site. Evidently the deep ditch was inundated by a underground river and sat full of water for quite some time.
The report goes on to say that a few months later, some workers spotted some movement in the water. When they threw some of their lunch in the water, the workers were amazed to see movement in the ditch.
Puzzled, the worked investigated and brought up the creature. When the creature tried to bite, the workers had to kill it with some nearby equipment. The workers estimated the size of the creature at 5 feet.
It looks to me like a horseshoe crab, which is not actually a crab at all to confuse things! What do you think, known creature or prehistoric beastie?