ZOO 1010 Study Guide
Chapter 15
Chapter 15 – Vertebrate Beginnings: The Chordates
1. Name and describe the five chordate hallmark characteristics.
2. How are some of those traits modified within humans?
3. Characterize the Subphylum Urochordata (tunicates).
4. When/how do tunicates possess the five chordate characteristics?
5. Distinguish between the class groups of the Ascidiacea (sea squirts) and the Thaliacea (salps).
6. Characterize the Subphylum Cephalochordata (the lancelet/Amphioxus/Branchiostoma).
7. How are vertebrates modified from the primitive protochordate form?
7. Characterize the earliest known vertebrates, the ostracoderms.
8. How, apparently, did vertebrates evolve a lower jaw?
9. Characterize and distinguish between the early jawed fish-like groups, the placoderms and acanthodians.
Key Terms – notochord, dorsal hollow nerve chord, pharyngeal slits/pouches, endostyle, postanal tail, tunic,
incurrent siphon, excurrent siphon, cranium, neural spines, paedomorphosis, ostracoderms, Meckel’s cartilage,
placoderms, acanthodians
Note: This study guide may not be all inclusive of material covered. The student is responsible for learning all
material covered in lecture and as expected as part of this course.