How would one identify a new species by proper kingdom, phylum, etc. based on the given information?
A new species has been discovered. The animal is a vertebrate and approximately 18-24 inches in length. Members of this species are covered in scales and are known to lay shelled eggs. Dissection has also shown that this animal possesses a four-chambered heart. Its skeleton is shown below, but the skull has been omitted. An image of the skeleton is shown below. A sample of the skull could not be obtained, but some characteristics of the skeletal structure of the head were observed: the skull lacks a sclerotic ring (bony ring which supports the eyeball), but possesses a secondary bony palate.
Identifying a species is simply a matter of looking at the given clues and figuring out what classification system science has already decided on based on those clues. As we are limited in space, below are a few ideas to help get you started.
To begin with, while there used to be only two biology kingdoms, Animalia, meaning animal, and Plantae, meaning plant, the introduction of the microscope soon led to new discoveries of organisms, and science now generally classifies nature into six kingdoms: Animalia, Plantae, Fungi, Protista, Archaea, and Bacteria. Since the new species is neither a plant; fungus; a protist, which would include an alga and a mold; nor a type of bacteria, such as an archaebacteria or a bacteria, that easily leaves the only possible kingdom as Animalia. Animals fall under the Animalia kingdom and are classified as animals because they are multicellular and have the ability to eat other organisims.
- Hence, the kingdom for the new species is Animalia.
Once we group an organism by kingdom, the next level is the taxonomic rank, called the phylum. Each different kingdom contains its own number of phyla; the kingdom Animalia can be grouped into 35 different phyla. The fact that the species lays eggs provides the best clue for phylum. Egg-laying species include fish, amphibians, reptiles, and birds, and all four species fit in with the phylum Chordate. Chordates specifically possess notochords, meaning hollow dorsal nerve cords and can also possess gill slits, an endostyle, and a tail, so it is very likely that, even though not listed, our species possess some or all of those things as well.
- Hence, our species' phylum is Chordate.
Our biggest clue for determining class is the fact that the species lays hard-shelled eggs as opposed to soft-shelled eggs. Both birds and reptiles lay hard-shelled eggs, while amphibians lay soft-shelled eggs. The next biggest clue for class is the scaly skin. Reptiles can lay either soft or hard-shelled eggs, but only reptiles with scaly skin lay hard-shelled eggs. Birds also do not possess scaley skin, only feathers.
- Hence, for sure, our species class is the reptile class, or Reptilia.
Our next task is to decide the order. The class Reptilia can actually be broken down into four different orders: Testudinata, Crocodilia, Rhynchocephalia, and Squamata. The biggest clue to determine order is the absence of the sclerotic ring. Most reptiles do have sclerotic rings. The only order that does not possess sclerotic rings is the order of Crocodilia.
- Hence, our species can be classified under the order of Crocodilia.
Next, orders can be broken down further into families. The order Crocodilia can be broken down into three families: Crocodylidae, which are true crocodiles; Alligatoridae, which are alligators and caimans; and Gavaialidae, which include both gharial and false gharial. The biggest clue for determining family is the presence of the secondary bony palate. Crocodiles evolved from protosuchians. Protosuchians had smaller, shorter snouts than crocodiles and longer limbs. They also had their palatine bones fused together to create a secondary bony palate that allowed the protosuchians to breathe through their noses underwater.
- Hence, the family for our species would be the Crocodylidae.
Next, all you have to do is keep looking through the clues to identify genus and species.