A lesson in ichnology: the modern fossil tracks

(click image to enlarge)

There are some nice unexpected opportunities for observing how the living animals leave their permanent tracks in the cement surfaces and thus comparing them with the fossil tracks left in the mud or wet sand that turned into the solid rock over the period of millions of years.

I took the photograph above at the British square (Britanski trg), that serves as a farmers' market place and a flea market (on Sundays) in Zagreb. The maintenance workers patched the cracks in the square with about a square meter of cement. Until the wet cement dried up, and hardened, several pigeons left their tracks on the surface making it a "modern fossil stomping ground" or a bio turbation. A keen observer will notice the cat trackways in the middle.