More than half a century after its discovery, the enigmatic "Tully Monster" has found classification by a team of researchers who say that they have finally figured out what it is, and where it fits in the tree of life: as a 307-million year-old vertebrate, it was related to the modern lamprey.
The strange fossils were first discovered in 1958 by amateur fossil collector Francis Tully near a mine in Illinois, and since then the remains of this creature have only been found in the Mazon Creek region of the same state. The strange dimensions and physique of the Tully monster, or Tullimonstrum gregarium, have puzzled scientists since its first discovery.
They appear to have been soft-bodied and tubular aquatic creatures, ranging in size from 6 to 12 inches. Their eyes projected out of a bar-distantly resembling that of a hammerhead shark. On one end they had a tail fin, and on the other their long, narrow snouts tapered off into a simultaneously toothy and claw-like apparatus. They once swam in the temperate coastal waters of a Carboniferous-era sea, among worms, jellyfish and sea cucumbers.
