Tyrannosaurus rex is probably the most widely known binomial. The formal introduction of this system of naming species is credited to Carl Linnaeus, effectively beginning with his work Species Plantarum in 1753.
Aestivation occurs in animals living in deserts and tropical regions. This is done to protect themselves from hot and dry climate, and due to the scarcity of food water. This can be seen in earthworms, molluscs, arthropods, reptiles and amphibians. A lungfish can aestivate and survive without water for three years.
Arthropod, (phylum Arthropoda), any member of the phylum Arthropoda, the largest phylum in the animal kingdom, which includes such familiar forms as lobsters, crabs, spiders, mites, insects, centipedes, and millipedes. About 84 percent of all known species of animals are members of this phylum.
The spicules are secreted by specialized mesenchyme cells known as scleroblasts. Scleroblast secreting a calcareous spicule is called calcoblast while that producing a siliceous spicule is called silicoblast.
Basic unit or smallest taxon of taxonomy/ classification is species. Species is a group of individuals that remain relatively constant in their characteristics; can be distinguished from other species and do not normally interbreed.