The 8×8 walking matrix of the stride of the horse walking from left to right.

<p>To each of the 8 columns and 8 rows belong given postures of the hind and fore feet pair, respectively, as shown by the black half horse contours on the top and left border. These horse contours coincide with the scientific drawings of the eight phases of the stride of walking horses published by Gambaryan <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0049786#pone.0049786-Gambaryan1" target="_blank">[11]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0049786#pone.0049786-Gambaryan2" target="_blank">[12]</a>. In a given cell of the matrix the fore feet attitudes belonging to the cell’s row are paired with the hind feet postures belonging to the cell’s column.</p

An erroneous modern, pre-Muybridgean horse drawing of Leonardo da Vinci (http://www.davincisketches.com).

<p>(A, B) The erroneous horse drawing fits into the cell <i>Eh</i> of the walking matrix. (A) Picture of the graphic art. (B) Schematic drawing of the horse. (C, D) Two possible corrections of the horse: C keeps the postures of the hind legs and corrects the attitudes of the fore legs, thus falls into the cell <i>Gh</i> of the walking matrix. D, keeping the postures of the fore legs and correcting the attitudes of the hind legs, belongs to the cell <i>Ee</i> of the walking matrix.</p

Cavemen Were Better at Depicting Quadruped Walking than Modern Artists: Erroneous Walking Illustrations in the Fine Arts from Prehistory to Today

<div><p>The experts of animal locomotion well know the characteristics of quadruped walking since the pioneering work of Eadweard Muybridge in the 1880s. Most of the quadrupeds advance their legs in the same lateral sequence when walking, and only the timing of their supporting feet differ more or less. How did this scientific knowledge influence the correctness of quadruped walking depictions in the fine arts? Did the proportion of erroneous quadruped walking illustrations relative to their total number (i.e. error rate) decrease after Muybridge? How correctly have cavemen (upper palaeolithic <em>Homo sapiens</em>) illustrated the walking of their quadruped prey in prehistoric times? The aim of this work is to answer these questions. We have analyzed 1000 prehistoric and modern artistic quadruped walking depictions and determined whether they are correct or not in respect of the limb attitudes presented, assuming that the other aspects of depictions used to determine the animals gait are illustrated correctly. The error rate of modern pre-Muybridgean quadruped walking illustrations was 83.5%, much more than the error rate of 73.3% of mere chance. It decreased to 57.9% after 1887, that is in the post-Muybridgean period. Most surprisingly, the prehistoric quadruped walking depictions had the lowest error rate of 46.2%. All these differences were statistically significant. Thus, cavemen were more keenly aware of the slower motion of their prey animals and illustrated quadruped walking more precisely than later artists.</p> </div

Statistical comparisons (binomial χ² test) between the numbers (<i>N</i>_incorrect) of incorrect quadruped walking illustrations (Table 1) to test differences between various ages (modern, post-Muybridgean, pre-Muybridgean, prehistoric), 2- and 3-dimensional depictions, and the random choice.

<p>For the random case the unity walking matrix has number 1 in its every cell (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0049786#pone.0049786.s044" target="_blank">Table S9</a>). Then the numbers of correct and incorrect quadruped walking illustrations are: <i>N</i>_correct = 16, <i>N</i>_incorrect = 44, total <i>N</i> = <i>N</i>_correct+<i>N</i>_incorrect = 60, resulting in an error rate of <i>N</i>_incorrect/<i>N</i> = 73.3% corresponding with the pure accident.</p

A prehistoric elephant depiction.

<p><i>Left</i>: Prehistoric illustration of an elephant from the Libian Tadrart Acacus (<a href="http://www.galuzzi.it" target="_blank">http://www.galuzzi.it</a>, the permission from the photographer, Luca Galuzzi is found in the Supporting Online Material). <i>Right</i>: Contour of the elephant. Here there are three possibilities (A, B, C) for the alignment of the assumed ground line: In cases (A), (B) and (C) the walking depiction falls in cells <i>Be</i>, <i>Cf</i> and <i>Bf</i> of the walking matrix, respectively, all being incorrect.</p

A correct modern, post-Muybridgean cavalry statue (Lajos Győrfi: cavalry sculpture of the Polish king Jan Sobieski III., Tatabanya, Hungary), the walking depiction of which fits into the cell <i>Ba</i> of the walking matrix.

<p><i>Left</i>: Picture of the statue (photo taken by Gabor Horvath). <i>Right</i>: Schematic drawing of the horse.</p

Contour of a bull copied from a picture of a prehistoric painting in the French cave Lascaux.

<p>(The original colour picture can be found in the following website: <a href="http://pittkyle123.wordpress.com/2011/02/15/cave-paintings-30000-years-ago" target="_blank">http://pittkyle123.wordpress.com/2011/02/15/cave-paintings-30000-years-ago</a>). The straight line represents the assumed ground line. LH: left hind leg, LF: left fore leg, RH: right hind leg, RF: right fore leg. This correct quadruped walking illustration falls in the cell <i>Bb</i> of the walking matrix.</p

Results of experiments 1 and 2.

<p>(A) Colour pictures and patterns of the degree <i>d</i> and angle α (clockwise from the vertical) of linear polarization of light reflected from the shady brown-and-white spotty horizontal sticky test surfaces with 1 (H1), 4 (H4), 16 (H16) and 64 (H64) brown spots used in experiment 2 and measured by imaging polarimetry in the blue (450 nm) part of the spectrum when the optical axis of the polarimeter was −30° from the horizontal. (B, C) Number <i>N</i> of tabanids captured by the brown and white regions of the vertical and horizontal spotty and sticky test surfaces in experiments 1 and 2 as a function of the area (m²) covered by one brown spot.</p

Results of experiment 4.

<p>(A) As Fig. 1A for the test surfaces used in experiment 4 when the optical axis of the polarimeter was horizontal. In the α-patterns the short bars represent the local transmission direction of the linear polarizer. (B, C) Number <i>N</i> of tabanids captured by the vertical and horizontal test surfaces in experiment 4. S16+: test surface with 16 linearly polarizing squares, the transmission direction of which is perpendicular to that of their surrounding regions. S4+: test surface with 4 linearly polarizing squares, the transmission direction of which is perpendicular to that of their surrounding regions. S16−: test surface with 16 linearly polarizing squares, the transmission direction of which is parallel to that of their surrounding regions.</p

Colour picture and patterns of the degree of linear polarization <i>d</i> and angle of polarization <i>α</i> (clockwise from the vertical) of a living shady black cattle measured by imaging polarimetry in the blue (450 nm) part of the spectrum.

<p>The optical axis of the polarimeter was horizontal, and the measurement was performed under an overcast sky. In the α-pattern double-headed arrows show the angle of polarization of reflected light at some places of the cattle coat. The background of the animal is white for the sake of a better visualization. The body surfaces of the cow from which light is reflected in a vertical plane polarize horizontally, while those from which light is reflected in a horizontal/oblique plane polarize vertically/obliquely.</p