cast cretaceous-period dinosaur dinosaur-tracks embedded footprint geological geology hard impressed impression imprint imprinted mark palaeontology paw paw-print prehistoric rock sharp solid toes canine dog dogs ice icy paws print slush snow white winter activity animals claws clear colors colours distinct evidence grainy indented light marked patterns sand shadows Soil surface surfaces textures tracks animal background backgrounds cat cats footprints catwalk cold copy space Foot print Footmark frost frosty frozen pad pastel path pet shape shapes track trail walk