Animal mesoderm forms by enterocoelic pouching, through invagination of the endoderm. The main deuterostome phyla are the Echinodermata and the Chordata. Echinoderms are exclusively marine and include starfish, sea urchins, and sea cucumbers. The chordates are dominated by the vertebrates (animals with backbones), which consist of fishes, amphibians, reptiles, birds, and mammals. The deuterostomes also include the Hemichordata (acorn worms). The Ecdysozoa are protostomes, named after their shared trait of ecdysis, growth by moulting. They include the largest animal phylum, the Arthropoda, which contains insects, spiders, crabs, and their kin. All of these have a body divided into repeating segments, typically
Ferreira's spiny tree-rat 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, Peru, Suriname and Venezuela. The etymology of the species name corresponds to the Latin word "" meaning "bristly". The description of "Mesomys hispidus" was conducted on a specimen collected by the naturalist Alexandre Rodrigues Ferreira during his travels in Amazonian Brazil, hence the species name. Initially deposited in the Museu Real d'Ajuda of Portugal, it has been brought to Paris in 1808 after the plundering of Lisbon by the armies of Napoleon. Then,