What is "ambulators"

Usage examples of "ambulators".

Except for the possession of three sets of limbs-two ambulators, two medial heavy manipulators, and two more at neck level for eating and to perform more delicate work, rather than the Tarlan's three sets of four—and a cranium covered by thick, blue fur that continued in a narrow strip along the spine to the vestigial tail, the general physical characteristics were remarkably similar.