Marine invertebrates at various trophic levels point at an important role in many ecosystems. Echinoderms (Greek for "spiny skin") is a phylum which contains only marine invertebrates. The adults are recognizable by their radial symmetry (usually five-point) and include starfish, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7000 living species, making it the second-largest grouping of deuterostomes (a superphylum), after the chordates (which include the vertebrates, such as birds, fishes, mammals, and reptiles). Echinoderms are unique among
Tuft-tailed spiny tree-rat (), meaning "hair". "Lonchothrix" is a member of the Echimyini clade of arboreal Echimyidae rodents. The closest relative of "Lonchothrix" is "Mesomys", reflecting the fact that these taxa have once been classified in the same subfamily (Eumysopinae). These two genera share phylogenetic affinities with several taxa and clades: (i) "Echimys", "Phyllomys", "Makalata", "Pattonomys", and "Toromys" ; (ii) the bamboo rats "Dactylomys", "Olallamys", "Kannabateomys" together with "Diplomys" and "Santamartamys" ; and (iii) "Isothrix". Tuft-tailed spiny tree-rat The tuft-tailed spiny tree rat ("Lonchothrix emiliae") is a spiny rat species from South America. It is known from Brazil south of the Amazon River,