Lab # 7 - ORNITHISCHIAN DINOSAURS (AMNH)

Introduction to the AMNH labs

The dinosaur halls at the AMNH are arranged cladistically. The purpose of Labs 7 - 10 is to identify the synapomorphic and autapomorphic characters for the various genera on display. Navigate your way around the exhibits using the AMNH book (by Dingus), and use Lucas and last weekís lab handouts as a guide to the anatomy. You need to go into considerably more detail in this lab than in the general class trip, but keep it clear and relatively simple.

There will be no formal weekly lab meeting for these labs. These labs will be due at the end of the semester; however it is strongly suggested that you discuss your work with the TAs between now and the end of semester. Do not put off doing these labs until the last week; they are VERY time-consuming!

Lab 6ís cladogram provides the relationships between the various groups of dinosaurs we are going to look at. The cladograms provided in this and the following labs follow the AMNH classification; this will sometimes be different to what we learn in class. For the purpose of the labs, follow the AMNH classification; for the exams however you only need to learn the classification given in lectures.

The basic instructions and format are the same for each lab. They are given in detail below; you may need to refer back to this lab for the complete instructions.
 

PART I

In this part we will look at the Thyreophora and Marginocephalia; cladograms are provided below for these groups. These cladograms are also in the exhibits.

For each of the 2 cladograms:

• Identify the synapomorphies on the cladogram (remember, there is one at each branching point, so there will be several on each cladogram).
• Draw this character as it is found in one taxon that contains it (i.e. if the character is found in 3 taxa, just draw it for one taxon, preferably the least-evolved taxon). You only need to draw the character, NOT the whole dinosaur!
• What are the functional uses (what did the animal use this feature for) and ecological implications (what does this say about the animalís environment) of these characters?
• Identify the autapomorphies (unique derived characters) for each taxon on the cladogram. A few are given in the text at each display & a few are in Lucas; the rest you will have to figure out for yourself by comparing with the other displays.
• Draw the autapomorphies for each taxon (again, you do not need to draw the whole dinosaur!)
• Place these unique derived characters in their functional andecological context.
• Compare the appearance in time of each taxon with their position on the cladogram. Are any apparently out of order?

• Identify the synapomorphies on the cladogram.
• Draw this character as it is found in one taxon that contains it.
• Place these shared derived characters in their functional and ecological context.
• Identify the autapomorphies (unique derived characters) for each taxon on the cladogram.
• Draw the autapomorphies for each taxon.
• Place these unique derived characters in their functional and ecological context.
• Compare the appearance in time of each taxon with their position on the cladogram. Are any apparently out of order?