Behold! The Trochate Rotifers!
Like all rotifers, trochates have three body segments: head, trunk, and foot. The head and trunk are supported internally by a calcified skeleton evolved from the mastax (used in basal rotifers to process food).
The mastax’s components (called trochi) are Y-shaped, with the base of the Y (the fulcrum) supporting the trunk. The arms of the Y are divided into many segments: the first segment (ramus) on each side is used to capture and process food. The other segments (manubria) support a pair of long fins used for swimming. The fan-shaped foot is used for steering.
The ancestral ciliated coronae (used by basal rotifers for swimming and food collection) have become gills. Basal eyespots have evolved into single lens eyes, convergent on the eyes of cephalopods and vertebrates. A pair of antennae in front of the eyes house chemoreceptors. The cloaca is on the rear dorsal end of the trunk. Eggs are attached to the foot and held between the manubria.
(please comment and critique. I’m trying to make sure this thing is plausible and appealing before figuring out how to get it up on the land. A snake with a head in the middle and tail tips on either side??)
(this is a Fellow Tetrapod creature, see www.thekingdomsofevil.com/?tag=fellow-tetrapod)