Dinosaur anatomy and systematics -Part 2

Directions: For this lab you will need to print it out and WRITE your answers on this paper. You will then need to scan or take pictures of each page and submit to Dropbox on Pilot. You will also need to utilize your book and/or Google to help with labeling and drawing.

The Saurischians and Ornithischians.

Laboratory Objective: This laboratory will introduce the student to two very important reptile groups. These groups have been distinguished by various skeletal features. These two groups the Saurischian defined as lizard hips and the Ornithischian defined as bird hips. This identification is based on differences with the pelvic structure.

Laboratory discussion: The Diapsids archosaur reptiles are typed primarily by their skeletal structures that allowed for an upright posture. A debate has been ongoing for about 150 years and questions still remain. In Saurischia the three pelvic bones point in different directions from the acetabulum, or hip socket, which is similar to other reptiles and in Ornithischia the ischium and pubis are in parallel to each other similar to birds.

Laboratory Activities:

1) Draw a cladogram of the major groups of dinosaurs discussed within your textbook (Google might be helpful for this question!!). Label and identify each group and provide a brief description.

2) Draw label and describe the pelvic structure of the Saurischian group.

3) Draw label and identify the pelvic structure of the Ornithischian group.

4) The diapsid reptiles consist of two large groups. Name and describe these two groups.

5) How do the ankle structures of the archosaur provide an insight to their phylogenetic relationship?