Pick the fastest floor
Three courses, one animal on each. Say which gets there first. Get it right and the ground stops being all one thing.
The numbers, as they happen
Every value in those panels is measured rather than decided. Nirody and colleagues walked Hypsibius across gels of two stiffnesses and tracked 989 strides. Stiffer ground: 160.5 ± 57.8 µm/s. Softer: 91.0 ± 32.0 µm/s. Polished glass gives the claws nothing to hook, and the animal cannot drive itself forward at all.
Watch the stance figure rather than the speed.
Call one right and the next round mixes surfaces within a single course, so the question stops being which floor is quicker and starts being how much of each you have to cross.
How this is built
The animal is the articulated body from our movement study: its trunk sections change angle and length as it walks, and its limbs are soft lobes with no knee in them. Drag the scene to turn it. The steel rule alongside is a real millimetre rule and the animals are drawn against it at their own size, which is the only honest way to say how small this is.
Substrate speeds, the stance-not-step-length mechanism and the glass result: Nirody JA, Duran LA, Johnston D, Cohen DJ (2021) Tardigrades exhibit robust interlimb coordination across walking speeds and terrains, PNAS 118:e2107289118, read from the bioRxiv preprint. Species given there as H. dujardini, which is H. exemplaris under the 2018 renaming. Each of these numbers is a sourced statement in the graph, with the page it came from. Agar stands in for the paper's stiff 50 kPa condition and the soft gel for its 10 kPa one; the course lengths are ours and change every round. Body colour carries nothing here and is free to change.