Paluxy River tracks

The Paluxy River tracks are a set of allegedly fossilized footprints 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.

Explanations
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 (some of the "man" tracks have clearly visible claw marks, indicating that the others probably also had claw marks that eroded) and some carved features that may have been doctored at a later date. In addition:

In some of the ‘man tracks’, it is possible to make out traces of toes to the side of the ‘foot’, which suggests that they are nothing more mysterious than highly eroded three-toed dinosaur tracks. Some also show claw marks at the ‘heel’ of the print, which is another feature typical of a dinosaur footprint but not of a human footprint. In at least one footprint sequence, there is the inexplicable coincidence that dinosaur tracks and ‘human footprints’ alternate. The Paluxy River ‘man prints’ may resemble human footprints superficially, but they lack the anatomy of real human footprints. Furthermore, dinosaurs and humans are of very different size and weight, but in the Paluxy River, tracks made by some undisputed dinosaurs and supposed humans are sunk to the same depth in the rock, which suggests that both types were made by creatures of the same general weight; there are tracks, made by different dinosaur species sunk to different depths. In the same way, the distances between footfalls of those tracks made to the same depth are spaced the same distance apart, showing that they were made by creatures with similar stride lengths.

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) no one could seriously suggest it is anything but a forgery. Nevertheless, 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 diehard 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.