Starfish Starfish Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea. Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or "basket stars". About 1,500 species of starfish occur on the seabed in all the world's oceans, from the tropics to frigid polar waters. They are found from the intertidal zone down to abyssal depths, below the surface. Starfish are marine invertebrates. They typically have a central disc and five arms, though some species have a larger number of arms. The aboral or upper surface may be smooth,
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,