Fossil Record 17(1): 59-67, doi: 10.5194/fr-17-59-2014
Do tracks yield reliable information on gaits? – Part 1: The case of horses
K. Kienapfel‡, S. Läbe§, H. Preuschoft|‡ Faculty of Biology, Ruhr University Bochum, Bochum, Germany§ Steinmann-Institut, Division of Palaeontology, University of Bonn, Bonn, Germany| Formerly Functional Morphology, Anatomical Institute, Ruhr University Bochum, Bochum, Germany
© K. Kienapfel, S. Läbe, H. Preuschoft. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Citation:
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Abstract
During their lifetime animals leave many tracks and traces behind, which canprovide insights into the animals' behaviour. Single footprints of extantvertebrates are frequently found in sediments all over the world, oftenarranged into trackways. The study of footprints and trackways lead tointerpretations about the mode of locomotion of the trackmaker. Here we showan approach to identify gaits from tracks.
A series of experiments with horses was performed to determine whether gaitscould be identified on the basis of fossil trackways, e.g. those left behindby sauropod dinosaurs of the Mesozoic era or Tertiary mammals, to unveiltheir locomotor abilities. The generally valid rules for quadrupedallocomotion were taken into consideration. Symmetrical gaits result in verysimilar trackways; a further differentiation can be made by application ofstatistics on step lengths, excursion angles and overstepping.
A clear difference exists between the trot and the pace. These rapid,symmetric gaits imply high ground reaction forces (GRF) because of their longphases of aerial suspension at higher speeds. The resulting GRF seem to be too high to be sustained by the limb bones of hugegraviportal animals like sauropods. Unfortunately, most of these factors arerarely available in the case of fossil tracks. Likewise, the asymmetrical,springing gaits can be excluded for sauropods because of the enormous GRF. Provided that limb length as well as trunk length can beapproximated, and left and right, as well as forefoot and hindfoot imprints canbe discriminated, the symmetrical gaits (walk, amble, pace, trot) used whenmaking a trackway can be discerned.
A series of experiments with horses was performed to determine whether gaitscould be identified on the basis of fossil trackways, e.g. those left behindby sauropod dinosaurs of the Mesozoic era or Tertiary mammals, to unveiltheir locomotor abilities. The generally valid rules for quadrupedallocomotion were taken into consideration. Symmetrical gaits result in verysimilar trackways; a further differentiation can be made by application ofstatistics on step lengths, excursion angles and overstepping.
A clear difference exists between the trot and the pace. These rapid,symmetric gaits imply high ground reaction forces (GRF) because of their longphases of aerial suspension at higher speeds. The resulting GRF seem to be too high to be sustained by the limb bones of hugegraviportal animals like sauropods. Unfortunately, most of these factors arerarely available in the case of fossil tracks. Likewise, the asymmetrical,springing gaits can be excluded for sauropods because of the enormous GRF. Provided that limb length as well as trunk length can beapproximated, and left and right, as well as forefoot and hindfoot imprints canbe discriminated, the symmetrical gaits (walk, amble, pace, trot) used whenmaking a trackway can be discerned.