Lecture 9: (
1. Four anatomical features
characterize the phylum Chordata
2. Invertebrate chordates provide
clues to the origin of vertebrates
3.
Humans and their closest relatives are vertebrates. This group includes other mammals, birds, lizards,
snakes, turtles, amphibians, and the various classes of fishes.
4.
Vertebrates share several unique features including a backbone, a series
of vertebrae.
5.
The vertebrates belong to one of the two major phyla in the Deuterostomia, the chordates.
Neural crest, pronounced cephalization, a
vertebral column, and a closed circulatory system characterize the subphylum
Vertebrata
6. Class Myxini: Hagfishes are the most
primitive living “vertebrates”
7. Class Cephalaspidomorphi: Lampreys provide
clues to the evolution of the vertebral column
8. Some extinct jawless vertebrates had ossified teeth and body armor
9. Vertebrate jaws evolved from skeletal supports of pharyngeal slits
10. Class Chondrichthyes: Sharks and rays have
cartilaginous skeletons
11. Osteichthyes: The extant classes of bony
fishes are the ray-finned fishes, the lobe-finned fishes, and the lungfishes
12. Tetrapods evolved from specialized fishes
that inhabited shallow water
13. Class Amphibia: Salamanders, frogs, and
caecilians are the three extant amphibian orders
14. Evolution of the amniote egg expanded the
success of the vertebrates on land
15. Vertebrate systematists are reevaluating
the classification of amniotes
16. A reptilian heritage is is evident in all
amniotes
17. Birds began as feathered reptiles
18. Mammals diversified extensively in the wake of the Cretaceous
extinctions
19. Primate evolution provides a context for understanding human origins
20. Humanity is one very young twig on the vertebrate tree