Dinosaur footprints or trackways (these being extended trails composed of many tracks) are not rare, nor, except in certain particular localities, are they abundant. One might ask why they are not more abundant, because there were undoubtedly a great many dinosaurs living on the Mesozoic continents during a span of perhaps a hundred million years, and these were all fairly active animals that moved about quite a lot. Think of the number of steps that were taken collectively by all of the dinosaurs of Mesozoic times; it staggers the imagination! And to show how it does stagger the imagination, let's play quite briefly with a few figures.

It has been calculated from observations that a work horse, not a free, untrammeled horse of the broad plains, but a plodding old dobbin, will take about 6,000 steps during the course of the day. A step means a stride with one foot, and since it is obvious that the horse plants all four feet on the ground during the day to a total of 6,000 times four, our horse, were he making prints each time he put a foot down, would make 24,000 footprints from sun to sun, and that would be a lot of tracks. Now, suppose the horse lives to an age of 20 years, which is not unusual for a horse, or a total of 7,300 days. By simple arithmetic it can be calculated that the horse would take about 44,000,000 steps during the course of his life, making a total of about 175,000,000 contacts of all four feet to the ground. There are a lot of potential footprints in a figure such as that.

Let us assume that the average dinosaur was not so active as a work horse, and may have taken only 3,000 steps a day, but let us also assume that the dinosaurs, being large reptiles, were comparatively long-lived, as are the large reptiles, such as crocodiles and turtles of our modern world. Thus it is not unreasonable to suppose that the total number of steps taken by the average dinosaur (if there was any such thing as an average dinosaur) might very easily have added up to as large a figure as that for the 20-year-old horse. Now think of the hordes of dinosaurs that inhabited the world for a stretch of time extending over about 100,000,000 years; multiply a figure of say 150,000,000 (a conservative estimate of foot-to-ground contacts for a single animal) by the untold millions of dinosaurs of Triassic, Jurassic, and Cretaceous times. The result must be somewhere in the billions of billions.