CH19 Crocodiles

What clade do crocodiles belong to?

Diapsida

What subclade do crocodiles belong to?

Archosauaria

What order do crocodiles belong to?

Crocodylia

Crocodiles are the only living members of the ___ other than birds.

Archosaurs

What regions are crocodiles found in?

Tropical regions

What is the temperament of alligators?

Mild

What is the temperament of caimans and crocodiles?

Aggressive

How many chambers do crocodile hearts have?

4

Alligators have osteoderms that form?

An armored dorsum

What are some of the aquatic adaptations of crocodiles?

-Eardrum cover

-Nostrils can close

-Nictitating membrane

-Webbed feet

-Powerful compressed tail

How does crocodile feeding impact respiration?

The choana leads directly to the nasal cavity for separate respiration and feeding.

What muscle is used to contract alligator lungs?

Diaphragmaticus

What type of air flow do alligators have?

Continuous

What is the attack strategy of alligators?

They are ambush predators that death roll and drown prey.

What do alligators do with extra food?

Cash it on the river bottom

Describe the sexual dimorphism seen in alligators

Males are larger.

What kind of male courtship do alligators have?

Males are territorial and have loud bellowing mating calls.

Describe the fertilization of alligators

Internal

Do alligators have a copulatory organ?

Yes

What type of parental care do female alligators display?

They build a large nest and lay amniotic eggs. When hatchlings are ready the female cracks the eggs and carries the young to the water in her gular pouch. She stays with the young for years and shares food.

Describe TSD in alligators.

At high temps the population is all males.

Where is the family Gavialidae found?

Asia

How many genera and species are in the family gavialidae?

-2

-2

What are the characteristics of the family gavialidae?

-Narrow snout

-Very aquatic

-Piscivorous

-Found in fast rivers

Where is the family Alligatoridae found?

NA, SA, and Asia

How many genera and species are in the family Alligatoridae?

-4

-9

What are the characteristics of the family Alligatoridae?

-Two subfamilies: alligators and caiman

-Broad jaws and hidden teeth

-Semi-aquatic

Where is the family Crocodylidae found?

Africa, Asia, and Central America

How many genera and species are found in the family Crocodylidae?

-3

-14

What are the characteristics of the family Crocodylidae?

-Lower jaw 4th tooth shows

-Narrow snout

-Burrow in river banks

-Mound nesters