Study #5: Test 3: Reptiles

Question 1

Origin of Amniotes (reptiles, birds, and mammals)

Answer 1

1. Broke ties to water 350 MYA
2. Amniotic egg: has extraembryonic membrane for protection from desication, cushioning and gas and waste material exchange.

Question 2

Amniotes

Answer 2

Split from a group of amphibian-like tetrapods

Question 3

anapsids

Answer 3

skull with no openings in temporal region

**turtles today (unless it turns out to be a 2ndary trait)

Question 4

Diapsids

Answer 4

• *upper (dorsal) & lower (lateral) openings in temporal region of skull
• *all living reptiles:
  
  1. Lepidosaurs: snakes, lizards, tuataras
     
     2. archosaurs: crocodiles (and birds) and other extinct groups

Question 5

Synapsids

Answer 5

Single pair of temporal (fenestra) openings in skull

Humans: located just behind jaw hinge)

Question 6

Age of reptiles

Answer 6

(165 MYA)

massive extinction 65 MYA

Question 7

Adv of Reptiles over Amphibians: 1. scales

Answer 7

1. Tough dry skin for protection ag drying out & injury
   2 Scales derived from epidermis; hard protein; thicker than fish scales
   3 Snakes and lizards shed skin; alligators slowly grow scales to replace wear; turtle shell is modified scales

Question 8

Adv of Reptiles over Amphibians: cont.

Answer 8

1. Amniotic egg that can develop fast in dry environment
   More efficient
   **jaws (kinetic skull; more places for big muscles)
   **Internal fertilization (required for egg with a shell)
   **water conservation (kidneys excrete urine; no water loss thru skin)
   **circulatory system
   **lungs: can suck by expanding ribcage
   **body support & limbs for traveling on land (legs out to sides; pelvic and pectoral girdles help with moving)
   **more complex nervous system (bigger cerebrum)

Question 9

General reptile traits

Answer 9

1. thick, dry skin
2. breathe with lungs
3. ectotherms
4. Very developed/diverse sensory organs
5. Kidneys process waste, little water loss, produce uric acid
   6 Parthenogenesis: reproduction w/out fertilization (no sex chromosomes); nest temperature determines sex (low temp- female; high temp- male)

Question 10

Order: testudines (turtles)

Answer 10

Bony shell
Limbs attached to ribs
Beak no teeth
Long lived

Question 11

Order: crocodylia (alligators, crocodiles, gavials, caimains)

Answer 11

Derived from archosaurs (along with birds and dinosaurs)
Not much change over 200 yr
Skull openings in front of eye
Triangular eye orbits
Laterally compressed teeth (different from other reptiles)
Long snout w/ nostrils at tip to breathe when partially submerged
Plate of bones and 2nd palate seperates mouth and nasal passages
Muscular, long tail for swimming and catching prey

Question 12

Order Sphenodontida: Tuataras

Answer 12

Only 2 living species (New Zealand islands)

Lizardlike but structure and attachment of teeth different: two rows of upper jaw and one row of lower jaw teeth

Question 13

Order Squamata: lizards, snakes

Answer 13

Skull: moveable bones; increase flexibility

Question 14

Suborder Sauria (lizards):

Answer 14

2 pr of legs
upper & lower jaw join anteriorly
legless lizards have remnants of pectoral girdle and sternum (geckos, iguanas, chamaleons, gila monsters, worm lizards)

Question 15

Suborder Serpentes (snakes)

Answer 15

Long
No limbs (some have vestigial pelvic girdles & appendages) ie rubber boa
Joints bet. vertebrae for flexibility
Moveable upper jaws
Upper and lower jaws can seperate to allow to swallow large prey
Only one lung and kidney
Excellent abilty to sense heat and smell
Jacobson’s organ in roof of mouth that pick up scent from tongue

Question 16

convergent evolution

Answer 16

when unrelated groups occupy similar habitats and evolve to resemble each other