Many animals employ gaits that result in track patterns appearing as a straight line, but the most typical animals whose tracks form nearly perfect straight lines are those employing direct register gaits, notably the fox and members of the cat family”
There is much more but this is the intro:
“## What Animal Tracks Go in a Straight Line?
Many animals employ gaits that result in track patterns appearing as a straight line, but the most typical animals whose tracks form nearly perfect straight lines are those employing direct register gaits, notably the fox and members of the cat family”