Scientific Taxonomy and Earth’s Biodiversity, Essay Example

There are hundreds of thousands of unique species in the Kingdom Animalia. In class Mammalia, two examples are the duck-billed platypus,  Ornithorhynchus anatinus, an egg laying mammal, and the short-beaked saddle-back dolphin,  Delphinus delphis, an aquatic mammal. Class Insecta is represented by the ghost tiger beetle (Cicindela lepida), an almost transparent beetle that lives in sand dunes and the giant cockroach,  Laxta pallida, a common pest known for invading homes worldwide. From class Ave, two examples are the wood duck,  Aix sponsa and the Apteryx owenii, the little spotted kiwi, a flightless bird from New Zealand. From phylum Echinodermata are the species  Rhizocrinus lofotensis, an ancient species of sea lily whose fossil remains take it back to the Jurassic, and the Asterias rubens, the common star fish. These eight species, while seemingly completely different, all all in the Kingdom Animalia and as such, do all share some common traits. All members of class Animalia are multicelluar and are heterotrophs, meaning that they rely on other species for food, either directly or indirectly (Myers, 2001).  All of these species also have internal organs, which are made of specialized tissue and perform specific functions necessary to the organisms survival (Myers, 2001).  The organisms in kingdom Animalia are taxonomically divided into classes and further subdivided down into order, family, genus and species depending on their specific features.

Class Mammalia      

Class Mammalia contains a known 5000 species that are divided into 26 separate orders (Wund and Myers, 2005). The Duck-billed Platypus,  Ornithorhynchus anatinus, is an egg laying mammal from subclass Prototheria. These are the most ancestral forms of the class Mammalia (Wund, Sorin and Myers, 2006).  The duck-billed platypus and other members of Prototheria have bird-like features and lack teeth as adults. Other members of this order include the short-nosed spiny echidna and the long nosed spiny echidna. Delphinus delphis, the short beaked saddle-back dolphin, is an aquatic mammal in the order Cetacea, which also includes whales and porpoises.

While seemingly very different, these two species of mammals share some common traits. Both are warm blooded, a feature that all mammals share. Even through the two species give birth differently they are both able to feed their young via lactation.  Both creatures also share the common mammalian trait of having  a four chambered heart and breathing air through lungs. Some differences between the two include the way the animals give birth to their young. While dolphins give birth to live young, the duck-billed platypus lays eggs. They also inhabit different eco-systems, since the short-beaked saddleback dolphin lives its life completely in the ocean, while the duck-billed platypus hunts and swims in fresh water but nests on land.

Class Insecta

Class Insecta features over one million names species, and accounts for a great majority of the species of animals on earth (Myers, 2001). Cicindela lepida, the ghost tiger beetles, is in the order Coleoptera, containing the many species of beetles.  This beetle lives in sand and has an almost translucent appearance. Other members of this order include species such as fireflies and glow-worms.  A well known, but not usually well loved, species in Insecta is Laxta pallida, the giant cockroach in the order Blattaria. Other members of this order include brown-hooded cockroaches and sand cockroaches.

While these two insects come from different orders, they do share some common traits. They both have a complete and complex digestive tract and a body that is composed of a head, a thorax and an abdomen, traits they share with all insects.  They both breathe through a tracheal system. This system is composed of “external openings called spiracles and increasingly fine branched tubules that carry gasses right to the metabolizing tissues (Myers, 2001).” Some key differences between the two include their larval form. While members of order Blattaria have an incomplete metamorphosis, with the young resembling the adults, only smaller, tiger beetles from order Coleoptera are grub like in their larval stage. They also inhabit different climates. The ghost tiger beetle inhabits sandy, dry areas while the Australian cockroach prefers moist, humid climates.

Class Aves

Animals in class Aves are vertebrates with feathers, “modified for flight and for active metabolism (Animal Diversity Web, 2001).” Species of Aves include Aix sponsa, the wood duck, from the order Anseriformes.  This order also contains geese and swans, two other fresh water birds that also migrate.  Another species of Aves,  Apteryx owenii, the little spotted kiwi, that, though feathered, is flightless. It is in the order Struthioniformes which also contains emu’s and ostriches, two other flightless birds.

These two birds share many similarities, including being feathered, laying eggs and having a specialized mouth called a beak that it toothless. Some key differences between the two are that the wood duck flys while the kiwi is a flightless bird. The kiwi is also a nocturnal species and the wood duck hunts during the day. The wood duck follows a seasonal migration but the kiwi does not migrate.

Phylum Echinodermata

Members of phylum Echinodermata, the Echinoderms, are sea creatures that are either planktotrophic or lecithotrophic and have three part paired coeloms (Mulcrone, 2005).” There are a 7000 species of Echinoderms that have been described today and another 13,000 extinct species that have been identified from the fossil record (Mulcrone, 2005).” Two examples of species of echinoderms include Rhizocrinus lofotensis, a sea lily or crinoid from the order bourgueticrinida and

Asterias rubens, the common star fish from the order forcipulatida. Other members of order forcipulatida  include Forbe’s sea star, Asterias forbesi and the sunflower star Pycnopodia helianthoides. Other members of order bourgueticrinida is in the class Crinoidea which also includes  sea lilies and feather stars (Kellogg and Fautin, 2001).

There are some similarities between  Rhizocrinus lofotensis and the common starfish. Both species have long arms which have specialized apparatuses for feeding. Both have their mouth located centrally to which the arms move food to. Both also have the power to regenerate lost body parts (Kellogg and Fautin, 2001). One key difference between the two is that  Rhizocrinus lofotensis is a sessile creature whereas the starfish moves along the substrate specialized suction like tubes on the bottom of its arms for locomotion.  Rhizocrinus lofotensis, like all Crinoids, is a filter feeder. The common starfish, on the other hand, is a carnivore and predator that uses its specialized tubed feet to assist it in preying on bivalves, gastropods and crabs.

References

“Animal Diversity Web” (2008) University of Michigan Museum of Zoology Web. Retrieved 6 November 2010 from http://animaldiversity.ummz.umich.edu/site/index.html

“Aves” (2001) Animal Diversity Web. Retrieved 6 November 2010 from  http://animaldiversity.ummz.umich.edu/site/accounts/information/Aves.html

Chidgey, Brooke (2000) “Asterias rubens: Common Starfish” Animal Diversity Web Retrieved 6 November 2010 at  http://animaldiversity.ummz.umich.edu/site/accounts/information/Asterias_rubens.html

Hammond, George (2010) “Blattaria: Cockroaches; Blattodea” Discover Life Web. Retrieved 6 November 2010 from http://www.discoverlife.org/mp/20q?search=Blattaria&guide=Arthropoda&cl=group/&flags=not_no:HAS:index_no:

Kellogg, D. and D. Fautin (2001). “Crinoidea” Animal Diversity Web. Retrieved 6 November 2010 from http://animaldiversity.ummz.umich.edu/site/accounts/information/Crinoidea.html

Mulcrone, Renee Sherman (2005) “Phylum Echinodermata: Diversity” Animal Diversity Web    Retrieved 6 November 2010 from http://animaldiversity.ummz.umich.edu/site/accounts/information/Echinodermata.html

Myers, Phil. (2001) “Kingdom Animalia” Animal Diversity Web  Web. Retrieved 6 November 2010 from http://animaldiversity.ummz.umich.edu/site/index.html

Myers, Phil (2001). “Insecta” Animal Diversity Web. Retrieved 6 November 2010 from             http://animaldiversity.ummz.umich.edu/site/accounts/information/Insecta.html

Wund, Matthew and Myers, Phil (2005) “Class Mammalia: Diversity” Animal Diversity Web  Web. Retrieved 6 November 2010 from http://animaldiversity.ummz.umich.edu/site/accounts/information/Mammalia.html

Wund, M., A. Sorin and P. Myers 2006). “Prototheria” Animal Diversity Web Web. Retrieved 6 November 2010 from    http://animaldiversity.ummz.umich.edu/site/accounts/information/Prototheria.html