1. ambulacral - Noun
2. ambulacral - Adjective
Of or pertaining to ambulacra; avenuelike; as, the ambulacral ossicles, plates, spines, and suckers of echinoderms.
Source: Webster's dictionaryThe fossil echinoderms had ambulacral grooves extending down the side of the body, fringed on either side by brachioles, structures very similar to the pinnules of a modern crinoid. Source: Internet
If a sea urchin is overturned, it can extend its tube feet in one ambulacral area far enough to bring them within reach of the substrate and then successively attach feet from the adjoining area until it is righted. Source: Internet
From this, radial canals extend along the arms of asteroids and adjoin the test in the ambulacral areas of echinoids. Source: Internet