1. The Animal Kingdom: The Deuterostomes
Chapter 30
The Animal Kingdom: The Deuterostomes

2. Main branches of deuterostomes
Echinoderms
Hemichordates (marine deuterostomes with three-part body, including proboscis, collar, trunk)
Acorn worms
Chordates

3. Characteristics of echinoderms
Spiny “skin”
Water vascular system
Tube feet
Endoskeleton
Larvae
Bilateral symmetry
Adults
Pentaradial symmetry

4. Class Crinoidea Oral surface is turned upward
Some crinoids are sessile
Class includes
Sea lilies
Feather stars

5. Crinoidea: feather star

6. Class Asteroidea Central disk with five or more arms
Tube feet for location
Members are sea stars

7. Class Ophiuroidea Longer, more slender arms than members of Asteroidea
Arms are used for locomotion
No suckers on tube feet
Members are brittle stars

8. Ophiuroidea: daisy brittle star

9. Class Echinoidea No arms Solid shell Covered with spines Members are
Sea urchins
Sand dollars

10. Echinoidea: sand dollar

11. Class Holothuroidea
Mouth is surrounded by a circle of modified tube feet that serve as tentacles
Members are sea cucumbers

12. Holothuroidea: sea cucumber

13. Phylum Chordata At some time in their life cycle, all chordates have
Notochord
Dorsal, tubular nerve chord
Pharyngeal slits
Postanal tail

14. Generalized chordate body plan

15. Subphyla of phylum Chordata
Urochordata
Cephalochordata
Vertebrata

16. Invertebrate chordates
Tunicates (subphylum Urochordata)
Are suspension-feeding marine animals with tunics
Larvae have typical chordate characteristics and are free-swimming

17. Tunicates (subphylum Urochordata), cont.
Adults of most groups are sessile suspension feeders

18. Tunicate body plan: lateral view of an adult tunicate

19. Tunicate body plan: internal structure of a larval tunicate (lateral view)

20. Invertebrate chordates
Lancelets (subphylum Cephalochordata)
Small
Segmented
Fishlike
Exhibit chordate characteristics

21. Cephalochordate body plan: lancelet

22. Evolution of chordates
Tunicates were probably first to evolve
Subphyla Cephalochordata and Vertebrata considered sister taxa by some
Common ancestor probably resembled tunicate larva

23. Evolutionary relationships of vertebrates

24. Shared derived characters of vertebrates
Verytebral column
Cranium
Neural crest cells
Pronounced cephalization
Muscles attached to endoskeleton

25. Major groups of jawless fishes
Ostracoderms (extinct)
Agnathans
Hagfishes (class Cephalaspidomorphi)
Lamprey (class Myxini)
or Craniates
Vertebrates
Hagfishes (systematist designation referring to invertebrate character of hagfishes)

26. Three lampreys attached to a carp
Suction-cup mouth of adult lamprey

27. Evolution of jawed fishes and amphibians
Class Chondrichthyes
Jaws
Two pairs of fins
Placoid scales

28. Structure of a placoid scale

29. Class Chondrichthyes, cont.
Sharks
Many species ovoviparous
Some species oviparous
Few species vivaparous
Rays
Skates
Oviparous

30. Internal structure of a shark

31. Bony fishes Class Actinopterygii Class Actinistia Class Dipnoi
Ray-finned fishes
Class Actinistia
Coelacanths
Class Dipnoi
Lungfishes

32. Perch, a representative bony fish

33. During the Devonian, bony fishes gave rise to
Actinopterygii
Lungs modified as a swim bladder
Evolved into modern bony fishes
Sarcopterygii evolved into
Lungfishes
Coelacanths

34. Sarcopterygii, cont.
Coelacanths and lungfishes apparently preadapted for life on land
Lungfish may have given rise to tetrapods
First successful tetrapods labyrinthodonts (ancestors of frogs and salamanders)

35. Diver swimming with coelacanth

36. An artist’s conception of labyrinthodonts

37. Class Amphibia Use moist skin as well as lungs for gas exchange
Three-chambered heart
Systemic and pulmonary circulations
Most return to water to reproduce

38. Class Amphibia, cont. Salamanders
Frogs (tadpoles undergo metamorphosis)
Toads
Caecilians

39. Modern reptiles: Chelonia mydas

40. Vertebrate adaptations to terrestrial life
Amniotic egg: amnion forms fluid-filled sac around embryo
Body covering that retards water loss
Physiological mechanisms to conserve water

41. Modern reptiles: Crocodilia niloticus

42. Class Reptilia is paraphyletic
Dinosaurs
Turtles
Lizards
Snakes
Alligators
Birds sometimes included

43. Modern reptiles: Basiliscus plumifrons

44. Reptiles Internal fertilization
Most secrete a protective shell around egg
Embryo develops protective membranes, including amnion, to retain moisture

45. Reptiles, cont. Dry skin with horny scales Lungs with many changers
Three-chambered heart with some separation of oxygen-rich and oxygen-poor blood

46. Paleontological discovery of feathered dinosaurs
Many biologists consider birds to be feathered dinosaurs; they classify as diapsids
Birds
Most reptiles

47. Caudipteryx (headless)

48. Reconstruction of Archaeopteryx

49. Birds: adaptations for powered flight
Feathers
Wings
Light, hollow bones with air spaces
Four-chambered heart
Very efficient lungs

50. Birds: adaptations for powered flight, cont.
High metabolic rate
Constant body temperature
Excrete solid metabolic wastes
Well-developed nervous system
Excellent vision and hearing

51. Mammals Hair Mammary glands Differentiated teeth
Three middle-ear bones
Constant body temperature
Highly-developed nervous system
Muscular diaphragm

52. Convergent evolution in placental and marsupial mammals

53. Monotremes (subclass Holotheria)
Oviparous
Duck-billed platypus
Spiny anteater

54. Marsupials (subclass Metatheria)
Young are born in an embryonic stage and complete their development in marsupium
Kangaroos
Opossums

55. Macropius giganteus
Macropius giganteus soon after birth

56. Placental mammals (subclass Eutheria)
Placenta permitting development within the uterus
Living placental mammals are classified into circa sixteen orders