|University of Bristol|
Dinosaur trackways are usually considered much more interesting than isolated tracks. A series of tracks can show us several features of the trackmaker's locomotory behaviour not obtainable from single tracks.
Measuring dinosaur trackways
Firstly we can reconstruct the stance and posture of the animal as it moved. Many dinosaur reconstructions from earlier this century gave these famous animals a sprawled or semi-erect stance (Charig, 1972). In the case of bipedal theropods, their trackways clearly indicate that these animals walked with both feet passing under the middle of its body. This upright stance is termed fully-erect.
Trackways can also show stride lengths. Stride length has been used to describe various measures, but is referred to here as the distance travelled by the same foot between consecutive foot-falls ("SL" in the above disagram).
By examining the size and shape of the footprint, scientists like R.McNeil Alexander (1976) can estimate the hip height of the trackmaking dinosaur. Once we know stride length and hip height we can estimate the speed at which the dinosaur was moving. Estimates of dinosaur speeds are discussed in a future section.
Alexander, R.M. (1976) Estimates of speeds of dinosaurs. Nature.Vol.261, pp.129-130.
Charig, A.J. (1972) The evolution of the archosaur pelvis and hind-limb: an explanation in functional terms. In Studies in Vertebrate Evolution (eds K.A.Joysey and T.S.Kemp). Oliver & Boyd, Edinburgh, pp.121-55.
Thulborn, R.A. (1990) Dinosaur Traces. Chapman & Hall, London.
Stance and Posture