Starfish to starfish by the French zoologist de Blainville in 1830. It is derived from the Greek "aster", ἀστήρ (a star) and the Greek "eidos", εἶδος (form, likeness, appearance). The class Asteroidea belongs to the phylum Echinodermata. As well as the starfish, the echinoderms include sea urchins, sand dollars, brittle and basket stars, sea cucumbers and crinoids. The larvae of echinoderms have bilateral symmetry, but during metamorphosis this is replaced with radial symmetry, typically pentameric. Adult echinoderms are characterized by having a water vascular system with external tube feet and a calcareous endoskeleton consisting of ossicles connected by a mesh of
Ferreira's spiny tree-rat in 1817, Anselme Gaëtan Desmarest described the species based on this specimen housed in the National Museum of Natural History (France) of Paris. Using ancient DNA technology, a portion of the mitochondrial cytochrome b gene has been sequenced from a small skin fragment of this holotype. DNA sequence comparisons then suggested that the specimen was originally obtained in eastern Amazonia north of the Amazon River, most likely in the Brazilian state of Amapá. Ferreira's spiny tree-rat Ferreira's spiny tree-rat, "Mesomys hispidus", is a spiny rat species from South America. It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana,