Observing guineafowl running on soft mud shows math used to calculate dinosaur speed may be inaccurate
Bob Yirka
news contributor
Lisa Lock
scientific editor
Robert Egan
associate editor
An international team has found that equations to determine the speed of a moving dinosaur based on prints in trackways may be inaccurate. In their published in the journal Biology Letters, the group urged test guineafowl to walk or run across a muddy course and then used standard equations to calculate their pace.
In the 1970s, paleontologists developed mathematical equations to determine the perambulation speed of a dinosaur based on the distance between footprints left behind in trackways and other factors. Such equations have been used ever since. But now, it appears the results of such calculations may have to be reconsidered, as the results of these new experiments suggest the equations may be wildly inaccurate.
To test the accuracy of the equations, the researchers turned to guineafowl—large birds and members of the only surviving dinosaur lineage. They first created muddy test tracks of different consistencies. Next, they coaxed the birds into walking and running across the test track and recorded them using high-speed cameras and timers to determine their true walking or running speed.
The researchers then used the standard equations to calculate the walking and running speeds of the birds using only their footprints in the test trackway. The results from the equations showed the birds walking and running faster than they actually did in every case (in some cases, by as much as a factor of four), and the consistency of the mud made no difference.
The research team suggests there are many possible reasons for the difference. The equations assume the dinosaurs were walking on a solid surface, not in mud, for example. Walking in mud tends to slow walking and running pace. Thus, the pace of dinosaurs walking across a muddy surface (and leaving behind footprints) would likely be slower. They note that the equations also make the assumption that a longer stride equates to a faster pace. In looking at the tracks made by the guineafowl, they found this was not always the case.
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More information: Tash L. Prescott et al, Speed from fossil trackways: calculations not validated by extant birds on compliant substrates, Biology Letters (2025).
Journal information: Biology Letters
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