Thylacosmilus
by Nick D.
The Thylacosmilus was a marsupial, saber toothed, feline like animal that lived from 8 million to about 2 million years ago and may have had the markings sort of similar to the Tasmanian wolf. One interesting thing is that they existed in South America. The second interesting is that it was not a feline; it was actually a marsupial meat-eating creature.
According to our classroom cladogram, this animal's ancestors evolved a backbone and a skull, which defines it as a vertebrate. Many other traits evolved after this, giving the Thylacosmilus a jaw (Gnathostomes), then four limbs (Tetrapods). This water tight egg was also amniotes. An amniote can lay a watertight egg. All vertebrates that reproduce on land and do not have to lay eggs in the water are amniotes. The next development in the evolution of the Thylacosmilus was the development of a hole in the back of the skull (Synapsid). Then it evolved three ear bones, making it a mammal.
I used the cladogram to help me determine that the Thylacosmilus is most closely related to the Irish Elk, Mammoth, Rabbit, Bat, Water Pig, and Lemur in our cladogram. To find this out I found where the Thylacosmilus was. Then I traced the branch to the Thylacosmilus' most advanced node. Heading in the opposite direction I take a different branch and find all animals that connect to that branch as the closest relatives. They are in the mammals clade. Borhyaenoidea are the most closely related South American marsupial carnivores. I did like the museum's cladograms as they were useful to me.
Last updated April 7, 2007.