Scientific Taxonomy and Earth's Biodiversity

All animals are classified under the kingdom Animalia. There are a wide range of species and orders under this kingdom. There are birds, echinoderms, insects and mammals, just to name a few. While all of these creatures may seem very different, they are all multi-cellular as well as heterotrophs (Myers, 2001). All animal cells do not have stiff wall cells (Myers, 2001). These animals share many differences as well as they do similarities.

First, birds are categorized under the class Aves. Similarities among birds consist of feathers, no teeth, and hard shelled eggs (Aves, 2001). One type of bird is a penguin. Penguins are categorized under the order sphenisciformes (Howard, 2003). Penguins are classified under this order because, according to Howard (2003), "Penguins are notable for their upright posture and stiff wings that cannot be folded against the body" (¶ 4). Penguins have a thick layer of fat underneath the skin and are also fairly large birds. There are no other birds classified under the order sphenisciformes; the order just includes living and extinct penguins (Scientific Classification, 2002). Another type of a bird is a blue jay. Blue jays belong to the order Passeriformes. According to Edwards and Harshman (2008), "The Passeriformes (or 'passerine' birds) are synonymous with what are commonly known as "perching birds"; this group also contains within it a major radiation commonly known as songbirds (oscine Passerines or Passeri)" (¶ 1). Passeriformes are various shapes, sizes and colors. According to Edwards and Harshman (2008), "...Passeriformes possess a suite of distinguishing characteristics, including a unique sperm morphology, a distinctive morphology of the bony palate, a simple yet functionally diverse foot with three toes forward and one (the hallux) oriented backwards, and a distinctive fore- (wing) and hind limb musculature" (¶ 3). Other birds belonging to the group Passeriformes include the rock wren and song sparrow. While penguins and blue jays belong to the same class, they are very different birds. Penguins are great swimmers. They have webbed feet that enable them to swim through the water. Blue jays do not have webbed feet. They have feet that enable them to grip whatever they are perching on. Penguins eat fish. Blue jays eat other insects, worms, and even other birds. Blue jays are relatively small in size. Penguins are relatively large. There are many differences between the two animals.

Other animals include echinoderms. Echinoderms have a calcareous skeleton on the inside of their bodies, live in marine environments, have nervous systems that are non-centralized, and are deuterostomes (Mulcrone, 2005). Echinoderms do not have a brain (Purple Sea Urchin, n.d.)One type of an echinoderm is the slender starfish. It belongs to the order paxillosida (Class: Asteroidea Starfish/Sea Stars, n.d.). Paxillosida is, according to Allaby (1999), "An order of starfish in which the mouth angle plates are large and derived from fused ambulacral ossicles" (¶ 1). Other examples of paxillosida include other types of starfish, such as the Sand Sifting Starfish and the Spiny Starfish. Another echinoderm is the purple sea urchin. Purple sea urchins belong to the order Echinoida, as all sea urchins do. They are marine invertebrates that are globular in appearance (Purple Sea Urchin, n.d.). Sea urchins have protective shells and spines that protrude from them (Echinus Acutus, n.d.). They are usually bottom feeders. Other animals belonging to the order Echinoida include the green sea urchin and the northern sea urchin. In contrast, starfish and sea urchins are different physically because they are anatomically different. Starfish have arms protruding from them, whereas sea urchins have spines. Starfish can also generate new arms. Similarities include their environment. They are both bottom feeders and live in marine environments. They both do not have brains.

Additionally, insects are also animals. Insects, according to Myers (2001), "...include a body composed of three tagmata, a head, thorax, and abdomen; a pair of relatively large compound eyes and usually three ocelli located on the head; a pair of antennae, also on the head; mouthparts consisting of a labrum, a pair of mandibles, a pair of maxillae, a labium, and a tongue like hypo pharynx; two pairs of wings, derived from outgrowths of the body wall (unlike any vertebrate wings); and three pairs of walking legs" (¶ 2). One insect is a firefly. Fireflies belong to the order coleoptera (Fleury, 2007). All beetles belong to the order coleoptera (Fleury, 2007). Though the name is deceiving, fireflies are beetles. According to Meyer (2005), "At rest, both elytra [front wings] meet along the middle of the back, forming a straight line that is probably the most distinctive characteristics of the order" (¶ 1). Two other animals that belong in the order coleoptera are the ground beetle and the click beetle. Another insect is the mosquito. Mosquitoes belong to the order diptera (The Mosquito: Order-Diptera, n.d.). Diptera is an order that means only true flies have a single pair of wings (Meyer, 2005). A mosquito is known as a true fly. According to Meyer (2005), "Flies have the highest wing-beat frequency of any animal" (Section 6). Other animals belonging to the order diptera include the horse fly and the flesh fly. While both fireflies and mosquitoes have wings and can fly, they are very different. Mosquitoes have only two wings, whereas fireflies have four wings (Meyer, 2005). Mosquitoes drink blood from other animals and fireflies do not. Fireflies can glow; mosquitoes cannot.

Furthermore, mammals are animals too. According to Wund and Myers (2005), "All mammals share at least three characteristics not found in other animals: three middle ear bones, hair, and the production of milk by modified sweat glands called mammary glands" (¶ 2). A deer is a mammal. Deer belong to the order Artiodactyls. According to Artiodactyls (n.d.), "This order of herbivorous (plant-eating) mammals includes cloven-hoofed animals with two hoofs on each foot (like pigs) and or four hoofs on each foot (like deer and cows)" (¶ 1). Another mammal is the squirrel. Squirrels belong to the order Rodentia (Stockard, 2005). According to Stockard (2005), "The prominent characteristic of rodents is the presence of upper and lower incisors that grow continuously throughout their lifetime" (p. 1). Other animals belonging to the order Rodentia are chipmunks and beavers. Even though squirrels and deer look very different, they have some common characteristics. Both have placental pregnancies. Both reproduce sexually. There are many differences between squirrels and deer. Squirrels are very agile and can climb and live in trees. Deer walk on all four legs on the ground and cannot climb. They do not live in trees, but rather live in forests and wooded areas.

In conclusion, though there are many different types of animals, such as birds, echinoderms, insects and mammals, some of them have certain things in common. They are all heterotrophs and are multi-cellular. However, they all belong to different orders and this is what makes them different: from where they live, what they eat, and their physical appearance.

M. Allaby. "Paxillosida". Encyclopedia.

"Artiodactyls". Enchanted Learning.

"Aves". Animal Diversity.

"Class: Asteroidea Starfish/Sea Stars". Salt Corner.

"Echinus Acutus". Seawater.

S. Edwards and J. Harshman. "Passeriformes: Perching Birds, Passerines Birds". Tolweb.

M. Fleury. "The Firefly or Lightning Bug: How and Why Fireflies Glow". Insects Suite 101.

L. Howard. "Sphenisciformes". Animal Diversity.

J. Meyer. "Coleoptera". Cals.

J. Meyer. "Diptera". Cals.

"The Mosquito: Order-Diptera". Planet Pets.

R. Mulcrone. "Echinodermata". Animal Diversity.

P. Myers. "Animalia". Animal Diversity.

P. Myers. "Insecta". Animal Diversity.