Nemertea analyses by molecular phylogeny are confident that members of Lophotrochozoa are more closely related to each other than of non-members, the relationships between members are mostly unclear. Most protostome phyla outside the Lophotrochozoa are members of Ecdysozoa ("animals that molt"), which include Arthropoda, Nematoda and Priapulida. Most other bilaterian phyla are in the Deuterostomia, which include Echinodermata and Chordata. The Acoelomorpha, which are neither protostomes nor deuterostomes, are regarded as basal bilaterians. Nemertea Nemertea is a phylum of invertebrate animals also known as "ribbon worms" or "proboscis worms". Alternative names for the phylum have included Nemertini, Nemertinea and Rhynchocoela. Although
Sea cucumber up the phylum Echinodermata. Echinodermata is known as one of the most distinctive and diverse phyla ranging from starfish to urchins to sea cucumbers and many other organisms. The echinoderms are mainly distinguished from other phyla by their body plan and organization. While the organisms in this phylum may not all look the same from the outside, their make-up is another story. There are three main characteristics that all echinoderms share. When mature, echinoderms have a pentamerous radial symmetry. While this can easily be seen in a sea star or brittle star, in the sea cucumber it is less distinct