Nerve net Nerve net A nerve net consists of interconnected neurons lacking a brain or any form of cephalization. While organisms with bilateral body symmetry are normally associated with a central nervous system, organisms with radial symmetry are associated with nerve nets. Nerve nets can be found in members of the Cnidaria, Ctenophora, and Echinodermata phyla, all of which are found in marine environments. Nerve nets can provide animals with the ability to sense objects through the use of the sensory neurons within the nerve net. The nerve net is the simplest form of a nervous system found in multicellular organisms. Unlike
Tullimonstrum characteristics of the well-known modern phyla, it was speculated that it was representative of a stem group to one of the many phyla of worms that are poorly represented today. Similarities with Cambrian fossil organisms were noted. Chen "et al." suggested similarities to "Vetustovermis planus". Others pointed to a general resemblance between "Tullimonstrum" and "Opabinia regalis", although Cave "et al." noted that they were too morphologically dissimilar to be related. In 2016 a morphological study showed that "Tullimonstrum" may have been a basal vertebrate, and thus a member of the phylum Chordata, with one study suggesting "Tullimonstrum" may be closely