Tetrapoda Lab 8 (Chapters 18, 19, and 20) Exam Next Week!faculty.orangecoastcollege.edu/grussell/biol182/8-chordates2.pdf · Tetrapoda Lab 8 (Chapters 18, 19, ... Taxonomy of phylum

Tetrapoda Lab 8 (Chapters 18, 19, and 20) Exam Next Week!

•! I will grade today’s lab for you before

you go, so you can take it with you to

study.

Taxonomy of phylum Chordata •! Subphylum Urochordata – sea squirts

•! Subphylum Cephalochordata - amphioxus

•! Subphylum Vertebrata –! Superclass Pisces

•! Class Agnatha

•! Class Chondrichthyes

•! Class Osteichthyes

–!Superclass Tetrapoda •!Class Amphibia

•!Class Reptilia

•!Class Aves

•!Class Mammalia

(a) Chick embryo

Gill pouches

Post-anal tail

(b) Human embryo

Phylum Chordata –!4 defining characteristics

•! Notochord

•! Dorsal, hollow nerve cord

•! Pharyngeal gill slits

•! Post-anal tail

Jaw

Bones

Legs

Amniotic egg

Milk / Fur Feathers

Amphibia: salamanders and

newts, frogs and toads, and

caecilians

Class: Amphibia

•! Ectothermic - can’t heat itself

•! Still tied to water

•! 3-chambered heart

•! Tetrapod legs to side of body

Amphibia

Colostethus

Frog external anatomy (no scales; naked)

•! Cross-section slide (skin):

epidermis, dermis, mucous glands,

poison glands

Class: Amphibia

www.wickersham.us/anne/frog.htm

Tympanic

membrane

•! Know the difference between a frog and a toad (parotoid gland)

Class: Amphibia

American toad

Bull Frog

•!Frog larva

Tadpole

Class: Amphibia Class: Reptilia Turtles,

Tortoises, Lizards, Snakes,

Crocodiles, Alligators, Tuatara

Class: Reptilia

•! Ectothermic (except shivering pythons)

•! No longer tied to water (amniotic egg)

•! 3-chambered heart

(4 in Croc and some monitor lizards)

•! Tetrapod legs to side of body

Class:

Reptilia

Class: Reptilia (amniotic egg) Reptile scales Epidermal in origin

Fish skin

Reptile scales •! For keying, look in the center of the

back

Reptile scales

Bony Dermal Plates

•! Turtle - Know the carapace (dorsal) and plastron (ventral)

Scale type: Bony Dermal Plates

Class: Reptilia •! Turtle - Know the carapace (dorsal) and plastron (ventral)

Scale type: Bony Dermal Plates

Class: Reptilia

male's plastron

is concave

female's plastron

is flat

Keying:

•! Use the dichotomous keys to determine

the taxonomy of the amphibian and

reptile specimens in lab.

Class: Amphibia & Reptilia Characteristics for Keys

Cloacal opening

Longitudinal Slit Transverse Slit

Characteristics for Keys

Pupil of eye

Pupil Vertical Pupil not Vertical

Characteristics for Keys PIT between eye and nostril

Characteristics for Keys

Parasphenoid (or vomerine) teeth

Roof of mouth

Characteristics for Keys

Tongue bicornuate behind

Tongue attached in the front

Class: Aves (birds) Class: Aves •! Endothermic

•! Feathers (modified scales)

•! Flight (some exceptions)

•! Hollow bones (why?)

•! Crop and Gizzard (no teeth)

•! 4-chambered heart

•! Amniotic egg

Class: Aves (birds) Bird feathers

Types: Down, filoplume, contour

warmth

Decoration

Flight

Class: Aves (birds) Bird feathers

Contour (flight) Feather

Construction:

Quill (Calamus), Shaft (Rachis)

Class: Aves (birds) Bird feathers

Contour (flight) Feather

Construction:

Barbs, Barbules

Class: Aves (birds) Bird beaks and feet:

Mandible

(lower bill)

Maxilla

(upper bill)

Class: Mammalia

•! Endothermic

•! Hair (insulates the body)

•! Mammary glands, (produce milk; nourish young)

•! 4-chambered heart

There are three major groups of

mammals

1.! Monotremes - the egg-laying mammals.

Platypus with pups echidna

2.! Marsupials - the so-called pouched

mammals (short gestation period)

Example: kangaroos, wallabies

3.! Placentals - most mammals

–!Have a relatively long

gestation period

–!Complete embryonic

development occurs

within the mother

Figure 18.22C

Jaw

Bones

Legs

Amniotic egg

Milk / Fur Feathers

Amniota:

Anapsida: turtles and tortoises

Diapsida:snakes, lizards, crocodiles, alligators, birds

Synapsida: mammals