20cm high on a wooden stand, this curious rock spike has just been identified by the Natural History Museum.  You might be disappointed that it is not a fossilised auroch horn or the fang of some truly spectacular dinosaur BUT it is far  too old to have anything to do with dinosaurs.  Imagine a piece of rock, probably from North Africa, that is 400 or so million years old, containing fossilised nautiloid (orthoceras) traces from the Ordovician or Silurian periods at the latter end of the Paleozoic era.  The rock has obviously been cut and polished to achieve its pleasing shape as an eyecatching and decorative piece but just imagine all that history if you can - that is what we find irresistible about objects like this. The fossil traces are actually from the breathing tubes that ran through the nautiloid shells as shown in the additional NHM photographs.