2 Interdisciplinary Paleontology: New approaches to solving complex paleontological problems (Part I)

Paleontology is increasingly drawing upon insight from other disciplines to solve complex problems and generate more accurate reconstructions of past life. This session will illustrate novel interdisciplinary research and provide tools to develop such approaches.

Monday, 18 May 2026
8:00 AM - 12:00 PM
Alvarado F

The Method of Alexander 1989 should be Abandoned for Estimating Dinosaur Speed from Tracks

Paper number: 2-11
Program: Technical Sessions
Time: 11:40 AM – 12:00 PM

Authors

  • John Rogers Presenting Author
    Central New Mexico Community College, Albuquerque, NM
  • Spencer Lucas
    New Mexico Museum of Natural History, Albuquerque, NM

Abstract

Dinosaur size and speed estimates from tracks provide important information for behavioral inferences and functional morphology. In 1976, R. McNeill Alexander published what became popular equations for estimating dinosaur hip height (size) and speed from tracks:

 h = 4L and u ≈ 0.25*g0.5SL1.67h-1.17,

where h = hip height (a proxy for size), L = hind footprint length, u = speed, g = gravitational acceleration,  SL = stride length (Alexander, 1976).

These equations rely entirely (for size) or heavily (for speed) on footprint length, L.  However, determining footprint length is problematic, particularly with undertracks (Lucas et al. 2024).  Footprint length is measured from tracks, and tracks can be measured in a variety of ways (Falkingham, 2016; Lucas et al., 2024), each leading to a different value for L.  Importantly, different footprint lengths yield different size and speed estimates for the same individual.

In 1989, Alexander introduced a newer, two-step methodology for estimating dinosaur speed (the hip height equation remained the same).  First, a graphical approach uses SL/h to determine dimensionless speed (DS). This first step depends on L since h=4L. Next, speed = DS x (leg length x gravitational acceleration)0.5, where leg length = 4L.

Importantly, this newer approach incorporates footprint length twice, thereby magnifying any error associated with footprint length.  Thus, Alexander’s (1989) methodology magnifies problems associated with L and should not be used for estimating dinosaur speed.

References

Alexander, R.McN., 1976, Estimates of speeds of dinosaurs: Nature, v.261, p. 129-130.

Alexander, R.McN., 1989, Dynamics of Dinosaurs and Other Extinct Giants. Columbia University Press, 167 p

Falkingham, P.L., 2016, Applying objective methods to subjective track outlines; in Falkingham, P.L., Marty, D., and Richter A., eds., Dinosaur tracks: the next steps. Indiana University Press, Bloomington, p. 73–80.

Lucas, S.G., Rogers, J.B., and Kvasnak, M.A., 2024, Photogrammetric study of the Clayton Lake Dinosaur Tracksite, Lower Cretaceous of northeastern New Mexico, USA: New Mexico Museum of Natural History and Science, Bulletin 95, p. 243-270.

Geological Society of America Abstracts with Programs. Vol. 58, No. 4

doi: 10.1130/abs/2026RM-410589

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