Relative size of a tardigrade compared to a single neuron of an insect.

Light micrographs; both images are to scale. Note that the entire anterior end of the tardigrade, including the brain and consisting of hundreds of cells [79], would fit into a single neuronal cell body of the insect. (A) Cobalt-filled dorsal unpaired median neuron (DUM neuron) from the thoracic ganglion of the locust Locusta migratoria. (B) Specimen of Macrobiotus cf. harmsworthi in ventral view. Abbreviation: so, neuronal soma. Scale bar: 100 µm (for A and B).