Property of Animal Diversity Web

Who is the American Crocodile?

Crocodylus Acutus

Domain- Eukarya
     Kingdom- Animalia
         Phylum- Chordata
             Class- Reptilia
                  Order- Crocodilia
                       Family- Crcodylidae
                           Genus- Crocodylus
Crocodylus acutus

Domain- Eukarya: Multicellular with membrane bound organelles and lacks cell walls.
Kingdom- Animalia: Eukaryotic, multicellular, heterotrophic, and motile at some stage in its life.
Phylum- Chordata: Possesses a notochord, dorsal nerve chord, gill slits, thyroid gland, and a post anal tail at some point in its lifetime.
Class- Reptilia: Cold blooded, amniotic egg (contains extra membrane for protection and does not need water), possesses lungs, and has epidermal scales.
Order- Crocodilia: Possess non-overlapping scales made of keratin with studs of bony plates (scutes), front feet have five separate toes, back feet have four webbed toes.

Family- Crocodylidae: Large aquatic reptiles that live in freshwater and consist of thAmerican Alligator(left) American Crocodile(right)ree subfamilies.
Genus- Crocodylus: Distinguishable narrow snout and overall smaller size than the alligator relative, broken down into 13 species.
Species- Crocodylus acutus: Crocodylus acutus, which comes from the Latin words krokodelios (“pepple worm”) and acutus (“pointed”), are noticeably lighter in color than their alligator relatives. These organisms are also very distinguishable in appearance from the alligator in the fact that they have a significantly narrower head and overall appearance. Two teeth that jut out noticeably from the lower jaw are also a key physical characteristic that alligators do not possess. Also they usually appear grayish green in color with a yellow underbelly and have less armor in scales than other species of crocodiles. >>>>


                 Phylogenetic Tree         The phylogenetic tree on the left shows the place of each Domain, supergroup and the sub-super group of Unikonta. If you start by finding the red colored box at the very right, you will find the animals, where Crocodylus acutus is located. As you work your way back to the left following the red shaded boxes, you are taking the path back through time as you follow the lineage of the American crocodile on a grand scheme of phylogeny. As explained in the reading above, Crocodylus acutus is a member of the Animals which is a Sub-Super group of Unikonta. Continuing to the left, the 5 major supergroups are listed, each of these is branched off of the domain Eukarya. The domain Eukarya is comprised of eukaryotic organisms which separates it from the other two domains. Finally, the final stop on the tree is the common ancestor from which all of life is believed to be derived from.


        The second phylogenetic tree that you see on the right is a hypothesis for the Crocodylus genus based on mitochondrial DNA. Starting on the left, the New World group is one of three groups that make of the Crocodylus genus, the other twMitochondrial DNA- Phylogenetic Treeo being Africa and Asia-Australia. Moving forward from New World, we see that this group is broken down into three other sub-groups due to differences in the mitochondrial DNA of the different types of crocodiles. Finally, as we get to the right side of the tree we see that Crocodylus acutus is shaded red, signifying that you have reached the end of your journey on finding where the American crocodile came from. The closest relative using the mitochondrial DNA is Crocodylus intermedius, which is the Orinoco crocodile found in northern South America. Because this phylogeny is based solely off of one characteristic, mitochondrial DNA, it is considered to be monophyletic.


Continue on and find out where these prehistoric beasts live in the present day. Habitat.