Ornithoscelida

High school (ages 12+)
Animals & Nature

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/ornithoscelida

1. What is the proposed clade?
2. What is the initial proposer?
3. Why was Ornithoscelida revived in 2017?
4. How is Ornithoscelida different from the old Saurischia and Ornithischia groups?

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the proposed clade?Ornithoscelida
2. What is the initial proposer?Thomas Henry Huxley
3. Why was Ornithoscelida revived in 2017?Scientists found new fossils and used better computer methods to study them. These helped them see that some dinosaurs fit better in Ornithoscelida than in older groups.
4. How is Ornithoscelida different from the old Saurischia and Ornithischia groups?The old groups were split mainly by the shape of the hip. Ornithoscelida groups dinosaurs based on many other bone features, not just the hip.

Clade: A monophyletic group comprising an ancestor and all of its descendants.
Phylogeny: The evolutionary history and relationships among individuals or groups of organisms.
Systematics: The study of the diversity of life and the evolutionary relationships between organisms.
Synapomorphy: A derived character state that is shared by two or more taxa and is hypothesized to have evolved in their last common ancestor.