evolution of the tetrapods. the origin of tetrapods the first vertebrates on land were amphibians in...

Evolution of the Tetrapods

Evolution of the Tetrapods

The Origin of Tetrapods• The first vertebrates on land were

amphibians in the _________(400 mya)• Arose from the rhipidistian (a family of

lobed finned fish) (based on morhpology) or a lungfish (DNA)

Origin of Tetrapods

Classification

• Phylum: Chordata• Subphylum: Vertebrata• Superclass: Gnathostomata• Class: Amphibia

– Order: Urodela (Salamanders)– Order: Anurans (Frogs and Toads)– Order: Apodans (Caecilians)

Class: Amphibia• Two lives

– refers to metamorphosis of many frogs• Skin smooth and moist (cutaneous

respiration)• _____ chambered heart with a double

circulation system

Order: Urodela

• 400 species• Salamanders• Retain their tail as

adults• Limbs are at right

angles to the body• Carnivorous• Most have internal

fertilization using a _____________

• Axolotl - paedomorphosis

Order: Anurans• 3500 species• Frogs and Toads• Lose their tail as

adults• Hind limbs are

adapted for jumping• Tongue connected to

front of mouth• Secrete mucus• __________ Fertilization

Order: Apodans

• 150 species• Caecilians• Legless and blind• Mostly Tropical• __________

Fertilization• Usually give birth

to live young.

Gas Exchange

Conditions for Respiratory Surfaces

• Large surface area• Thin• Moist

Aquatic vs. Terrestrial• Less than ____%

oxygen• Oxygen amounts

decrease as the temperature increases

• Aquatic animals use large amounts of energy to obtain oxygen (____%)

• About _____% oxygen

• Developed invaginations to increase surface area and decrease evaporation

• Terrestrial animals may use only 1% - 2% of its energy to obtain oxygen

Gills• Found in echino-

derms, mollusks, annelids, arthropods, some vertebrates

• Countercurrent Gas Exchange

Countercurrent Gas Exchange• Maintains gradient over the whole length of

the capillaries• Extracts ____% of the oxygen from the

water

Tracheal Systems

Diffusion Lungs

• Found in invertebrates• Gas moved primarily by diffusion

– may be increased by body movement

• Modifications– snails - cavity with gill modified into lung– scorpions and spiders - invaginations of

the abdomen

Ventilation Lungs

• Found in amphibians, reptiles, mammals and birds

• Pharynx• Larynx• Trachea• Bronchi• Bronchioles• Alveoli

Alveoli

Ventilating The Lungs

• _______ Pressure Breathing– pushes air down

trachea– seen in frogs and

other amphibians

• ________ Pressure Breathing– suction created

by diaphragm– seen in

mammals

Negative Pressure Breathing

Evolution of the _________ Egg

• Allows animals to complete their entire life cycle on land

• Has shell that retains water (or is lost when kept inside mammals)

• Specialized extraembryonic membranes (not part of the animal)

The Amniotic Egg

Evolution of the Amniotic Egg

• Amnion - Protects from dehydration and mechanical shock

• Yolk Sac - Nutrient storage• Albumin (egg white) - Nutrient

storage• Allantois - stores waste, gas

exchange• Chorion - gas exchange• *** Good Essay….

Amniotes

How Reptiles differ from Amphibians

• Tough, dry skin• Amniotic egg• Crushing or

gripping jaws• Copulatory organs• More efficient

circulatory system with a higher blood pressure

• More developed lungs (thoracic breathing)

• Better water conservation

• Better body support and limbs

• Better nervous system

Classification

• Phylum: Chordata• Subphylum: Vertebrata• Superclass: Gnathostomata• Class: Reptilia (not real)

– Class: Testudines (Turtles and Tortoises)

– Class: Spenodontia (Tuataras)– Class: Squamata (Lizards and Snakes)– Class: Crocodilia (Crocodiles and

Alligators)

Reptile Radiation

• Synapsids (therapsids) - led to mammals

• Sauropsids– _________

(turtles)– _________ (all

others)

Class: Testudines (Chelonia)• Protective Shell

– Carapace (top)– Plastron (bottom)

• Land and Sea -Evolved on land and returned to water (lay eggs on land) Largest,

Leatherback Sea Turtle (2,000 lbs!)

Class: Testudines (Chelonia)

• No _____• Most move legs

to breathe • TDS (low:male

high:female)

Class: Sphenodontia• ___________

– Two living species(New Zealand)

– Not a True Lizard (no external ears, different teeth)

– Very Primitive (similar to mesozoic reptiles

– Well developed eye below skin?

Class: Squamata• Lizards

– geckos, iguanas, skinks, chameleons

• terrestrial, burrowing, aquatic, arboreal

• moveable eyelids (in most)

• Paired copulatory organs

Class: Squamata• Tongue usually not

bifurcated• Lower jaw loosely

connected to skull• TSD (female to male)• ______________

Class: Squamata

Class: Squamata

Class: Squamata

Gila MonsterGila Monster – –

• One of three One of three poisonous lizardspoisonous lizards

• Protein in saliva Protein in saliva studied to treat studied to treat diabetes.diabetes.

Class: Squamata• Snakes• Lack limbs• Lack moveable

eyelids

Class: Squamata

• Bifurcated tongue • _________ organ• Pit Vipers (Loreal

Pits)

Class: Squamata

• Venom– Viperidae (Folding

Fangs)• Rattlesnakes

– Elapidae (Fixed Front Fangs)

• Cobras, Sea Snakes, Coral Snakes

– neurotoxic– hemotoxic

Class: Squamata

Feeding Adaptations

• Teeth curved and pointed inward• Hinged __________ bone• Bones of jaw are attached by

muscles and ligaments• Moveable palate• Elastic skin• No sternum

Class: Crocodilia• Largest living reptiles

• Most closely related to dinosaurs

• Complete secondary ________

• Four chambered heart (?)

• Nest temperature (female/male)

Dinosaurs and Pterosaurs

• Dinosaurs – Ornithischian– Saurischian– Pterosaurs– flying reptiles

Animal Structure and Function

(4th exam)

Animal Nutrition

Nutritional Requirements

• Undernourished– not enough

calories

• Overnourished– too many calories

• ____________– missing one or

more essential nutrients

Essential Nutrients

• Essential Amino Acids• Essential Fatty Acids• Essential Vitamins• Essential Minerals

Essential Amino Acids

• Found in proteins– 20 different types

• 8 essential in adult humans (9 infants)

• all in animal proteins• vegetarians need to

eat grains and beans

__________ – Essential in infantsHistidine

Essential Fatty Acids

• Unsaturated fatty acids– used to make phospholipids for

membranes

Essential Vitamins

• Fat Soluble– stored in fat– ___________

• Water Soluble– excreted in urine– B complex and C

Essential Minerals

• Inorganic nutrients– Calcium & Phosphorous

• bones

– Iron• anemia

– Iodine• thyroid hormones

– Sodium, Chlorine, & Potassium• nerve function, water regulation

Food Types

• Heterotrophic– Herbivores– Carnivores– Omnivores– Insectivores

Feeding Adaptations

• Suspension Feeders

Feeding Adaptations

• Substrate Feeders

Feeding Adaptations

• Fluid Feeders

Feeding Adaptations

• Bulk Feeders

Intracellular Digestion

• Inside cells• All animals• Exclusive in:

– Protista– Porifera

Extracellular Digestion

• Outside cells• All animals above the sponges• Two Types

– _________________– _________________

Gastrovascular Cavity

• One opening• Found in

Cnidaria and Platyhelminthes

Alimentary Canal

• Two openings• Allows for

specialization– Mouth– Pharynx– Esophagus– Crop– Gizzard– Stomach– Intestine– Anus

Mammalian Digestion• Accessory Glands

– salivary glands– pancreas– liver (emulsification)– gallbladder

• Peristalsis • Sphincters• “Food”

– bolus– acid chyme– feces

Macromolecule Digestion

Carbo Protein NucleicAcids

Fat

Mouth Initial

Stomach Initial

Intestine Main Main InitialMain

InitialMain

Dentition and Diet• Nonmammal

vertebrates• Carnivores

– canines (grasping/puncturing)

– incisors (tearing)– molars and premolars

• (crushing and grinding)

• Herbivores• Omnivores

Digestive Tracts

• Carnivores– ________

digestive system

– small cecum

• Herbivores– ________

digestive system

– large cecum