Chordates

NotocordDorsal hollow nerve cord

GillsPostanal tail

Figure 34.0 A snake skeleton exhibits defining characteristic of a vertebrate

Figure 34.2 Chordate characteristics

Figure 34.3 Subphylum Urochordata: a tunicate

Figure 40.8 Internal exchange surfaces of complex animals

Fig. 27.3, p. 457

nerve cord notochord

gut

oral opening

atrial opening (water that passed through pharynx leaves this way)

pharynx with gill slits

Figure 34.4b Subphylum Cephalochordata: the lancelet Branchiostoma

Fig. 27.4, p. 457

DORSAL, TUBULAR NERVE CORD

NOTOCHORD

PHARYNX WITH GILL SLITS TAIL EXTENDING PAST ANUS

epidermisanuspore of atrial cavity

hindgutgonadaorta

midgutsegmented musclestentacles

around mouth

segmented muscles

Figure 34.5 Early fossil vertebrates: Haikouella (top), Myllokunmingia (bottom)

Figure 34.6 The neural crest, embryonic source of many unique vertebrate characters

• Agnathans

Figure 34.8 A hagfish

Fig. 27.7, p. 459

Tentacles Gill slits (twelve pairs) Mucous glands

Gill openings (seven pairs)

Figure 34.9 A sea lamprey

Figure 34.10 Hypothesis for the evolution of vertebrate jaws

Fig. 27.6, p. 458

supporting structures

gill slit

jaw

spiracle (small gill slit)

jaw support

jaw

Early jawless fish (an agnathan)

Early jawed fish (a placoderm)

Modern jawed fish (a shark)

In-text, p. 463

• Chondrichthyes

Figure 34.11 Cartilaginous fishes (class Chondrichthyes): Great white shark (top left), silky shark (top right), southern stingray (bottom left), blue spotted stingray (bottom

right)

Fig. 27.8, p. 460

• Osteichthyes

caudal fin

dorsal fin

pectoral fin (one of two)

pelvic fin (one of two)

anal fin

muscle segmentsfin supports

brain

olfactory bulbheart

livergallbladder

stomach

intestineswim bladder

kidney

anusurinary bladder

Fig. 27.9, p. 461

Figure 34.12a Ray-finned fishes (class Actinopterygii): yellow perch

Figure 34.12b Ray-finned fishes (class Actinopterygii): long-snouted sea horse

Figure 34.13 Anatomy of a trout, a representative ray-finned fish

Figure 34.14 A coelocanth (Latimeria), the only extant lobe-finned genus

Figure 34.16 Skeleton of Acanthostega, a Devonian tetrapod fish

• Amphibians

Figure 34.17 Amphibian orders: Newt (left), frog (right)

Figure 34.17x1 Frogs

Fig. 27.12, p. 463

Figure 34.18 “Dual life” of a frog (Rana temporaria)

Amniotes

• Produce eggs with membranes

Figure 34.19 Amniotic egg

Figure 34.21 Taxonomic classes of amniotes

• Reptiles

Figure 34.22 A hatching reptile

Fig. 27.13, p. 464

snout

olfactory lobe (sense of smell)

forebrain, midbrain, hindbrain regions

spinal cord

vertebral column gonad

kidney

cloacaintestine

stomach

liver

heart

esophagus

unmatched rows of teeth on upper and lower jaws

Figure 34.24 Extant reptiles: Desert tortoise (top left), lizard (top right), king snake (bottom left), alligators (bottom right)

Fig. 27.15, p. 466

hollow fang

venom gland

Figure 34.24ax Sea turtle

hard shell

ribs of endoskeleton

Fig. 27.15, p. 466

Figure 34.24bx Banded gecko, Coleonyx varigatus

Figure 34.24cx Emerald tree boa

• birds

Fig. 27.16b, p. 468

Figure 34.25 Form fits function: the avian wind and feather

Fig. 27.17, p. 469

skull

radius

humerus

pectoral girdle internal structure

of bird limb bones

two main flight muscles attached to keel of sternum

sternum

pelvic girdle

ulna

shaft

barb

barbule

Figure 34.26 A bald eagle in flight

Figure 34.27 Archaeopteryx, a Jurassic bird-reptile

Figure 34.27x Archaeopteryx

Figure 34.28a Cretaceous theropod dinosaurs with putative feathers from Chinese sediments: Sinoauaropteryx

Figure 34.28b Cretaceous theropod dinosaurs with putative feathers from Chinese sediments: Caudipteryx

Figure 34.29 A small sample of birds: Blue-footed boobies (top left), male peacock (top right), penguins (bottom left), perching bird (bottom right)

Figure 34.29x Penguin march