A Phylogenetic Tree Shows That Birds and Crocodiles Share Many

question 17

Multiple Choice

A phylogenetic tree shows that birds and crocodiles share many features.A hypothesis based on this tree predicts that these features are present in a common ancestor.Which of these predicted traits is supported by fossil evidence?

• A)four-chambered heart
• B)singing for territory
• C)eggs and nests
• D)singing to attract mates

---

Definitions:

Axial Skeleton

The part of the skeleton that consists of the bones of the head and trunk of a vertebrate.

Appendicular Skeleton

Part of the skeleton that includes the bones of the limbs and the pectoral and pelvic girdles, facilitating movement.

Cavitiy

A hollow space within the body or one of its organs; however, the correct spelling is "cavity."

Skull

The bone structure that forms the head, protecting the brain and supporting the structures of the face.