Paluxy River tracks
The Paluxy River tracks are a set of allegedly fossilized foot prints that appear to be human, located right alongside dinosaur tracks in the Paluxy River valley, Texas. These tracks were touted by creationists for many years as proof that man had walked with dinosaurs, and hence were evidence supporting Young Earth Creationism.
It has now been conclusively and scientifically demonstrated that the supposed man tracks are not those of humans. Both sets of tracks are highly weathered, so it's impossible to draw too many precise conclusions. The "man" tracks appear to be not human in origin but seem to have a few different features collaborating to form the illusion of human tracks, including excessive weathering of the details and some carved features that may have been doctored at a later date. There are numerous other tracks attributed to humans, but none stand up to any scientific scrutiny. The Burdick Print seems to show a well defined human foot preserved in stone, but given the 15 inch length and the hilariously over defined toes (for something that would have been imprinted in soft mud) only an idiot would suggest they were anything but a forgery. Nevertherless, close scrutiny has been done and confirmed most tracks like these are forged carvings being passed off as genuine fossilised human footprints. The State Park Ledge tracks, small indentations found in a rock formation in Dinosaur Valley, Somervell County, Texas, have been jumped on by track enthusiasts but are just later erosion features with only a superficial resemblance to anything actually man-made.
Only the most die hard creationists still use this as evidence for a young earth any more. Answers in Genesis includes the Paluxy tracks among those "Arguments that should be avoided" as even they can recognise blatant cases where further research is still needed, new research has invalided aspects of it, or biblical implications may discount it.