Sauropelta
by Ara B.
The Sauropelta was a stocky, broad dinosaur with circular armor plates embedded on its back and tail. These plates were protection from jumping, snatching dinosaurs and airborne attacks. It’s different from more advanced thyreophorans in that it does not have a large club on its tail for attacking. A few examples of later thyreophorans are the Shamosaurus and Ankylosaurus. Both evolved from the common ancestor of these three animals, and both have clubs on their tails. The Sauropelta also has large spikes on its neck and small studs along the side of its body.
The Sauropelta’s first evolved trait was a backbone and skull (Vertebrate). Then it evolved a jaw (Gnathostome), 4 limbs (Tetrapod), and a watertight egg (Amniote). The next advances in line were a pair of holes in the upper mouth (Sauropsids) and a hole in the hip socket (Dinosaur). Finally it evolved a backward pointing pubis bone (Ornithischian) and bony body armor or spikes (Thyreophoran). This classifies it as an ornithischian dinosaur, specifically a thyreophoran.
According to our cladogram, the Sauropelta is most closely related to the Shamosaurus. The most advanced trait that these animals share is bony body armor or spikes. The most important difference between these two creatures is the fact that the Shamosaurus has a bony club on its tail and the Sauropelta does not. I figured out what animal was most closely related to the Sauropelta by looking at the most advanced trait it evolved. Then I followed the path of the other branch instead of the path that eventually became the Sauropelta. The animal at the end of this branch was the Sauropelta’s closest relative. I figured out the difference because I found out what a Shamosaurus has and I noticed that it had a club and the Sauropelta did not. The animal that is most closely related to the Sauropelta, according to the museum’s cladogram, is the Panoplosaurus. It shares bony body armor and a tail with no club. I used the cladograms at the museum much in the same way I used our cladogram. I traced back to the most advanced node and found out what the trait for that node was. I figured out the most advanced shared trait by looking at the most advanced node that they shared, and the trait at that node was the most advanced trait that they shared.
Last updated April 7, 2007.