Domain: Eukarya         →        Kingdom: Animalia
                         Phylum: Chordata        →      Class: Sauropsida
                          Order: Plesiosauria        →    Family: Pliosauridae
                            Genus: Kronosaurus      
→   Species: Queenslandicus

When looking further into the classification of the Kronosaurus, we noticed that there are several modern day species that could in fact be relatives of this giant creature.

This picture shows a preparator (Arnie Lewis) working on the 9 foot long (2.7 m) skull of Kronosaurus queenslandicus at the Harvard Museum of Comparative Zoology.

Domain: Eukarya
This specific domain is one in which the organism's cells contain a true nucleus.

Kingdom: Animalia
Organisms within Animalia are multicellular.  They are also heterotrophs, a term meaning that they rely either directly or indirectly on other organisms as sources of nourishment.
The range of organisms within this kingdom is very broad. Organisms such as the Domesticated Cat, Alces alces and even the Asian Elephant can be classified within the kingdom.

Phylum: Chordata
Here we can see that all of these organisms have a series of structures in common.  They have a notochord.  This is a structure that is present in the embryos.  As the organisms mature, this structure can become reduced or absent all together.  Another shared structure within this phylum is the pharyngeal slits.  These slits were originally used as a tool in the filter feeding process (Everhart, 2009).  They would filter our particles of food and enable them to stay in the animal's body to later be put into the digestive tract.  Within this phylum, one can see fish, amphibians, reptiles, birds and mammals.  Animals such as the Cane Toad, Albacore tuna, Crocodylus actus and Colinus virginianus, along with many others, can be seen within the phylum.

Class: Sauropsida
This class is comprised of vertebrates. Sauropsida includes what was classically known as "Reptilia" along with birds and dinosaurs.

Order: Plesiosauria
This is an extinct order of Mesozoic marine reptiles.

Family: Pliosauridae
This family existed from the Earliest Jurassic to the early Late Cretaceouw. 

Genus: Kronosaurus
This is an extinct genus of short neck pliosaurs.

Species: Queenslandicus
Kronosaurus qeenslandicus
is from the Early Cretaceous of Queensland.  This is the largest known pliosaurid. Using it's pairs of limbs, this monstous carnivore traveled the oceans and inland seas during the Mesozoic.