In this lab, we dissected an owl pellet and tried to use the bones in the pellet to piece together skeletons of organisms that the owl may have eaten. WE also compared and contrasted the bones to human bones. To dissect the owl pellet, we used probes and forceps.
Based on the bones that we were able to find, we concluded that the organism was either a shrew or a vole. We believe this because the vertebrae in its our creature's tail matches both the shrew and the vole, and it has the correct number of ribs as well. There was also a femur that looked very similar to that of the vole and shrew. However, because we lacked a skull, we could not deduce exactly which organism it was. As seen below, we managed to piece together a skeleton that looked very similar to a vole or a shrew. In the diagram in the book, the shrew had 12 ribs on each side, which is what we managed to obtain. The tail vertebrae in our picture also supports the hypothesis that the organism is either a shrew or a vole.
Both humans and the shrew/vole skeleton have ribs, and we both have 24 ribs total, with 12 on each side. The shrew/vole also had floating ribs, much like we do. They also had a skull similar to us, with eye sockets, a hole for the nose, and mandibles for the jaw area. Their appendicular skeleton is also quite similar as they also have a femur tibia and fibula, much like we do. One key difference is that they have a full tail vertebrae column, whereas humans only have remnants of a tailbone. This is because we do not use our tails for balance and overtime it was not selected for so it reduced in size. See below for a comparison picture. Also, although we do have the same general bones, the shape of the vole/shrew's tibia and fibula was different; in humans, the bones are really two that are connected in the top and bottom, whereas in the rodent, it is one bone with a section that branches out and in again. Finally, a big difference was the entire pubic region. Since humans walk on two legs instead of four, there is a difference in the structure of our respective pelvises.
