Interspecific variations in tracks and trackways of extant crocodiles

Footprints and trackways from 12 species of extant crocodylians are compared to give an overview of the morphological variation found among the tracks of modern crocodylians. Crocodylians often overprint the manus prints and drag their hindfeet along the sediment surface. The extent of tail and belly dragging varies significantly with gait, age and progression speed of the animal. The dragmark from the tail is not always situated in the middle of the trackway, but can be offset toward one side of the trackway. The divarication angle between pedal digits I-IV is higher among Alligatoridae, averaging 74°, than among Crocodylidae, which have an average angle of 42°. Fresh feces from crocodylians are typically cylindrical to tapering and composed of concavo-convex units. They often have one or two bends of approximately 140°, a feature also observed in putative crocodylian coprolites