Amplectobelua

Amplectobelua (meaning "embracing beast") is an extinct genus of late Early Cambrian amplectobeluid radiodont, a group of stem arthropods that mostly lived as free-swimming predators during the first half of the Paleozoic Era.

Amplectobelua was a giant radiodont, with the largest specimen of A. symbrachiata reaching up to 90 cm (3.0 ft) in body length excluding the frontal appendages and tail.

The size of the flaps decrease posteriory, and each of their frontal margin have rows of vein-like structures (strengthening rays).

Amplectobelua shares a unique feature among radiodonts with Ramskoeldia, in having gnathobase-like structures (GLSs) underneath its neck region, at least 6, up to eight.

Its structure was suitable to firmly grasp and manipulate prey to the mouth or tearing off pieces from larges carcasses.

Size comparison of two species
The movement of the frontal appendages of A. stephenensis