Kingdom Animalia - Phylum Chordata Four Key Characteristics of Chordates: 1. ____________________ – a longitudinal, flexible rod between the digestive tube and nerve cord. It

provides skeletal support throughout most of the length of a chordate. 2. Dorsal, hollow ___________________________ 3. _____________________________

Functions of pharyngeal slits: A. _______________________ structures in many invertebrate chordates B. _______________________ in aquatic vertebrates C. Develop into parts of the ______, ________, and ________ in terrestrial vertebrates

4. Muscular, post-anal _________

Invertebrate chordates provide clues to the origin of vertebrates.

Subphylum Urochordata 1. Commonly called ―__________________.‖ 2. The deepest-branching lineage of chordates, still resemble other chordates during their larval stage. 3. Undergo a radical metamorphosis to form a sessile adult with few chordate characteristics. 4. Suspension feeders as adults.

Subphylum Cephalochordata 1. Commonly called ―__________________.‖ 2. Blade-like in shape, up to 5 cm long. 3. Adult lancelets retain key chordate characteristics: the notochord; dorsal, hollow nerve cord;

numerous gill slits; and post-anal tail all persist. 4. Suspension feeders, using nets of mucous on pharyngeal slits. 5. Frequently leaves burrow to swim to a new location. 6. Feeble swimmers, but their swimming mechanism resembles that of fishes through the coordinated

contraction of serial muscle blocks.

Tunicates and lancelets may provide clues about the evolutionary origin of the vertebrate body plan.

Subphylum Vertebrata Traits:

1. ____________________________________ 2. Brain covered by a skull (______________) 3. Ten organ systems:

a. ________________________ b. ________________________ c. ________________________ d. ________________________ e. ________________________ f. ________________________ g. ________________________ h. ________________________ i. ________________________ j. ________________________

Trends in Vertebrate Evolution

1. Body support and movement came to depend on a ________________, not a notochord 2. Nerve cord evolved into a ____________________ and __________ 3. ________ evolved 4. __________ became more important than __________ (movement onto land) 5. Increasingly efficient ________________________________ 6. _________________ evolved into the diverse limbs of the amphibians, reptiles, birds, and mammals

Craniata – ―__________________‖ are chordates that have a head with a skull and brain. The origin of a head opened up a completely new way of feeding for chordates—______________________________. Chordata Classes

1. ______________ – Lampreys and Hagfish 2. ______________ (Extinct) – Eel-like, jawless fish 3. ______________ (Extinct)– Jawed, armored fish 4. ______________ – Sharks and Rays 5. ______________ – Bony Fish 6. ______________ - Frogs, Toads, Salamanders, & Caecilians 7. ______________ - Snakes, Turtles, Crocodiles, & Lizards 8. ______________ - Birds 9. ______________ – Monotremes, Marsupials, & Placentals

Miscellaneous Terminology:

1. ________________________ – egg-laying 2. ________________________ – giving birth to free-living young 3. ________________________ – eggs hatch internally, young born free-living

Class Agnatha – Lamprey and Hagfish 1. ______________________ body 2. Skeleton made of __________________ 3. Fins not ____________ 4. Circular mouth, no jaws (____________________) 5. __________________ or ____________________ of dead or weak organisms

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

Lamprey Hagfish

Class Conodonta (Extinct) Conodonts were the first known vertebrates with ______________________ skeletal elements in their mouth and pharynx. They ranged in size from 1-40 cm in length. It is now widely agreed that conodonts had large eyes, fins with fin rays, chevron-shaped muscles and a notochord.

Infraphylum Gnathostomata – ―__________________________‖ are chordates with jaws that evolved from skeletal supports of the pharyngeal slits Other characteristics common to gnathostomes:

A. Enhanced ______________ systems, including the ______________________ B. An extensively mineralized ________________________ C. ___________ appendages

Class Placodermi (Extinct) The earliest gnathostomes in the fossil record are an extinct lineage of armored vertebrates called ―____________________.‖

LE 34-14a

Coccosteus, a placoderm

LE 34-9

Slime glands

(b) Dunkleosteus, a large, predatory placoderm

A reconstruction of a conodont, based on fossil evidence

Class Chondrichthyes- Sharks and Rays 1. Skeleton made of __________________ 2. Lateral line system (sense organ for detecting ____________________) 3. ______________________ body 4. Prominent ________ 5. Five to seven __________________ per side of head 6. Keen sense of __________

Class Osteichthyes – Bony Fish

1. Stiff skeleton reinforced by hard ________________________ 2. Lateral line system 3. __________________ – bony cover over gills 4. ______________________ – buoyancy organ - allows fish to swim at different levels 5. ______-chambered heart (atrium for collecting blood, ventricle for pumping blood) 6. ________________ body 7. Well-developed __________ 8. Keen sense of __________ 9. Respiration through ___________ 10. Countershading

Tetrapods – vertebrates with four limbs: One of the most significant events in vertebrate history was when the fins of some lobe-fins evolved into the limbs and feet of tetrapods. Tetrapods have some specific adaptations:

A. Four limbs and feet with ____________ B. ________ for detecting sound C. A ________ with a mobile head

LE 34-16

Nostril

Brain

Spinal cord

Swimbladder

Dorsal fin Adipose fin(characteristicof trout)

Caudal fin

Anal fin

Intestine

Gonad

Pelvicfin

Urinarybladder

AnusLateralline

Cut edgeof operculum

Gills

KidneyHeart

Liver

Stomach

LE 34-15b

Southern stingray (Dasyatis americana).

LE 34-15c

Spotted ratfish (Hydrolagus colliei).

LE 34-15a

Blacktip reef shark (Carcharhinus melanopterus).

Pectoral fins Pelvic fins

LE 34-19

Bonessupportinggills

Tetrapodlimbskeleton

Class Amphibia – Frogs, Toads, Salamanders, & Caecilians 1. Two body forms (__________ form differs from the ____________ form) 2. __________________________ 3. Four legs 4. Respiration through lungs, mouth, and skin (__________________ respiration) 5. __________-chambered heart 6. Thin, moist ________ 7. Return to water to ______________

________________ are a group of tetrapods whose living members are the reptiles, birds, and mammals. Characteristics of the amniote egg: A. __________ – food source B. __________ – fluid-filled sac where the embryo develops C. __________ – gas exchange D. __________ – waste products Amniotes have other terrestrial adaptations, such as relatively ______________________ skin and the ability to use the ______________ to ventilate the __________. Class Reptilia – Snakes, Turtles, Alligators, & Lizards

1. Skin covered with ____________ (water-proofed with ______________) 2. Amniote eggs with a ________________ shell 3. ________________ (body temperature determined by environment and behavioral thermoregulation) 4. Internal fertilization 5. Kidneys conserve __________ 6. Well-developed __________, behaviorally better adapted than amphibians 7. __________-chambered heart (two atria and one partially-divided ventricle)

Miscellaneous:

A. Four-chambered heart in crocodilians – a trait shared with birds B. Lizards and snakes have Jacobson’s organ for sense of smell– tongue fits into pits on roof of mouth

LE 34-21a

Order Urodela. Urodeles (salamanders)retain their tail as adults.

LE 34-21b

Order Anura. Anurans, such as this poison

arrow frog, lack a tail as adults.

LE 34-21c

Order Apoda. Apodans, or caecilians,

are legless, mainly burrowing amphibians.LE 34-24

Extraembryonic membranes

Shell

Embryo

AllantoisAmnion

Amniotic cavitywith amniotic fluid

Chorion Yolk sac

Yolk (nutrients)

Albumen

Class Aves (Birds)

1. __________ – derived from skin for insulation and flight 2. Amniote egg – ___________________________ in shell 3. Lightweight, _________ bones – an adaptation for flight 4. High rate of ____________________ 5. __________ penetrate into bones – increases O2 uptake 6. ________-chambered heart 7. Forearm adapted for flight (__________) 8. ______________ (Internal control of body temperature) 9. ______________ beak

LE 34-27a

Tuatara (Sphenodon punctatus)

LE 34-27c

Wagler’s pit viper (Tropidolaemus wagleri), a snake

LE 34-27b

Australian thorny devillizard (Moloch horridus)

LE 34-27d

Eastern box turtle (Terrapene carolina carolina)

LE 34-27e

American alligator (Alligator mississipiensis)

LE 34-28

Bone structure

Feather structure

Wing

ForearmWrist

Finger 1

ShaftShaft

Barb

Palm

Finger 2

Finger 3

Barbule

Hook

Vane

Biologists have traditionally placed reptiles and birds in separate classes of vertebrates. However, the tree shown here is more consistent with both the fossil record and with an analysis of derived characters among living species.

Class Mammalia 1. Body covered with ________ 2. Young nourished by _________________________ 3. Extended care of young 4. Capacity to learn and repeat behaviors necessary for survival 5. Variety of __________ (heterodont dentition)

a. ______________ – cut food b. ______________- piercing, gripping c. ______________ – crushing, grinding

6. __________________ – muscular layer beneath lungs that aids in respiration 7. Three major groups:

a. Egg-laying (__________________) b. Pouched (____________________) c. Placental (____________________)

8. ________-chambered heart 9. ______________________

Mammals evolved from __________________ in the late Triassic period. Synapsids were a group of amniotes with a hole behind the eye socket called the temporal fenestra. The jaw was remodeled so that two former jaw bones were incorporated into the mammalian __________________. Monotremes Marsupials LE 34-33

Short-beaked echidna (Tachyglossus aculeatus),

an Australian monotreme. Monotremes have hair

and produce milk, but they lack nipples. Monotremes are the only

mammals that lay eggs (inset). Eutherians (Placental Mammals)

A. Longer period of __________________ B. Complete embryonic development within a

uterus joined to the mother by the ____________

LE 34-34a

A young brushtail possum. The young of marsupials are born very

early in their development. They finish their growth while nursing

from a nipple (in their mother’s pouch in most species).

Eastern Cottontail rabbits (Sylvilagus floridanus) eat grass, ferns, and leaves. The female gives birth about a month after mating. She has between one to nine babies, although she usually will have four to five young. The female feeds the young twice a day. The babies are weaned after about three weeks and leave the nest after about seven weeks. The female may mate again just hours after giving birth. Females can have three or four litters a year. Eastern cottontails are ready to mate when they are three months old.