Vert Bio Lecture 16

Front 1

What do Anapsids lack?
How many species are alive today?

Back 1

Anapsids lack Temporal Fenestra.
All species of Anapsids are extinct (pareiasaurs and procolophonids).

Front 2

What distinguishes Diapsids?
How many species are alive today?

Back 2

Diapsids are distinguished by TWO TEMPORAL FENESTRA on each side of their head.

Rhinocephalia (2 species)
Squamata (7750 species)
Crocodylia (23 species)
Aves (8700 species)

Front 3

What was the original Phylogenetic hypothesis for turtles?

Back 3

Turtles are Anapsids and lack temporal fenestra, which makes them the sister group to all other reptile groups.

Front 4

What is currently considered the correct Phylogenetic hypothesis for turtles?

Back 4

Turtles are considered Diapsids with highly modified skulls.

Front 5

Do turtles have an extensive fossil record?

Back 5

Yes. Quite extensive. (All the way from late TRIASSIC). Largely due to the heavy bony shells.

Front 6

What do Anapsids lack?
How many species are alive today?

Back 6

Anapsids lack Temporal Fenestra.
All species of Anapsids are extinct (pareiasaurs and procolophonids).

Front 7

What distinguishes Diapsids?
How many species are alive today?

Back 7

Diapsids are distinguished by TWO TEMPORAL FENESTRA on each side of their head.

Rhinocephalia (2 species)
Squamata (7750 species)
Crocodylia (23 species)
Aves (8700 species)

Front 8

What was the original Phylogenetic hypothesis for turtles?

Back 8

Turtles are Anapsids and lack temporal fenestra, which makes them the sister group to all other reptile groups.

Front 9

What is currently considered the correct Phylogenetic hypothesis for turtles?

Back 9

Turtles are considered Diapsids with highly modified skulls.

Front 10

Do turtles have an extensive fossil record?

Back 10

Yes. Quite extensive. (All the way from late TRIASSIC). Largely due to the heavy bony shells.

Front 11

What was the name of the earliest fossil turtle?
What was its general body design?

Back 11

Proganochelys: looked basically like a modern turtle. It was a sister group to all other turtles. Lacked neck retraction.

Front 12

What was the "Archelon ischyros"?

Back 12

A giant sea turtle about 3 meters in length that held a flipper span of about 4.5 meters.

Front 13

Approximately how many species and families of turtles are in existence today?

Back 13

There are approximately 260 species in 13 families. Habitats include; terrestrial, freshwater aquatic, and marine aquatic.

Front 14

What are the two major clades of turtles (based on neck retraction)?

Back 14

Cryptodires: hidden-neck turtles, neck bends in a vertical plane, completely retract head into shell,
10 families and ~200 species.

Pleurodires: side-neck turtles, neck bends in a horizontal plane, and cannot truly retract head into shell.

Front 15

What are two exceptions of Cryptodires that cannot retract their heads?

Back 15

Sea turtles and snapping turtles cannot retract their heads.

Front 16

What are the two parts of the shell?

Back 16

Carapace (upper shell): Consists of ribs, dermal bone, and vertebrae.

Plastron (Lower shell)

Front 17

What is the major difference between turtles and all other vertebrates?

Back 17

A turtles shoulder girdle is on the INSIDE of the ribs, while all other vertebrates' shoulder girdle is on the OUTSIDE of the ribs.

Front 18

What covers the shells of most species of turtles?

Back 18

Keratinized scutes.

Front 19

Skin covers the shells of three aquatic species of turtles. What are they?

Back 19

1) Carettochelyidae
2) Dermochelyidae
3) Trionychidae

(Pig-nose and spiny softshell are included there).

Front 20

What is the general trend of Carapace shape in turtles?

Back 20

Aquatic species generally have flattened shells (streamlined to reduce drag and cost of swimming).
Terrestrial species generally have domed shells (for adaptation against predators (can’t get mouth around))

Front 21

GIve an example of reduced ossification in turtle shells.

Back 21

African pancake tortoise (Malacochersus).
The shell is very flat, soft, and flexible, and the turtle avoids predation by wedging itself into crevices and inflating its body, then pushing with its limbs.

Front 22

In regards to feeding, what is the general trend for tortoises?

Back 22

Herbivorous.

Front 23

In regards to feeding, what is the general trend for sea turtles?

Back 23

Carnivorous.

(Also, most aquatic turtles can only feed in water).

Front 24

In regards to limb morphology, what is the general trend for tortoises?

Back 24

Elephantine-like (club) feet.

Front 25

In regards to limb morphology what is the general trend for freshwater turtles?

Back 25

Forefoot paddle varies in degree of webbing.

Front 26

In regards to limb morphology what is the general trend for Sea turtles and Carettochelys?

Back 26

Forelimbs modified into flippers.

Front 27

What are the two forms of aquatic locomotion in turtles?

Back 27

Rowing and Flapping.

Front 28

What are some need-to-know things about rowing? (in regards to turtle locomotion)

Back 28

All non-marine turtles (except Carettochelys)
Asynchronous forelimb movements
Propulsion via drag-based thrust
Intermittent thrust: power stroke and recovery stroke
Good for accelerating, and low-speed maneuvering

Front 29

What are some need-to-know things about flapping? (in regards to turtle locomotion)

Back 29

“Aquatic flight” used by sea turtles and Carettochelys
Synchronous forelimb movements
Propulsion via lift-based thrust
Continuous thrust: generate thrust on up and down stroke
Good for long distance swimming, not good for maneuvering at low speeds or accelerating.

Front 30

How is the turtle heart divided?

Back 30

Completely divided atria.
Incompletely divided three-chamber ventricle.

Front 31

How many circuits of blood flow are in a turtle heart?

Back 31

Two, the SYSTEMIC and PULMONARY.

Front 32

What is a 'right-to-left intracardiac shunt'?

(IN TURTLES)

Back 32

Blood from the pulmonary circuit is redirected (i.e., diverted) into the systemic circuit. (All within the heart).

Front 33

How do turtles breathe?

Back 33

The LUNGS of turtles are large and attached to the shell, and to a sheet of connective tissue. Muscular movements of limbs and girdles change body cavity volume. ABDOMINAL MUSCLES have a large importance in turtle breathing.

Front 34

Which muscle is responsible for turtle INHALATION?

Back 34

Oblique abdominus (OA) = inhale

Front 35

What is the muscle responsible for turtle EXHALATION?

Back 35

Transverse abdominus (TA) = exhale

Front 36

What is an example of a turtle species that uses CLOACAL RESPIRATION?

Back 36

"Rheodytes leukops" (Fitzroy River turtle).

Front 37

How does CLOACAL RESPIRATION work?

Back 37

Outpockets from the cloaca are lined with villi to increase surface area. Turtles rarely surface to breathe and swim with cloaca open; pump water in and out at high rates
(15-80 cycles per minute).

Front 38

Are turtles ectotherms or endotherms?
How do they raise their temperature?

Back 38

Ectotherms.
Raise their temperature by basking.

Front 39

What is the trend for sexual dimorphism in turtles?

Back 39

Generally, females are larger than males in most freshwater species, and males are larger than females in most tortoises.

Front 40

What are some reproduction and nesting habits of turtles?

Back 40

Males use penis for internal fertilization.
All turtles lay eggs.
No parental care of young.
Most females nest on dry land because usually embryos die if they are below sea level.

Front 41

What is embryonic diapause?

Back 41

Embryonic diapause is an early or late pause in development initiated by environmental conditions.

Front 42

There are three types of TSD. What are they?

Back 42

la: most common; males decrease as temperature increases.
lb: males increase as temperature increases.
ll: graph looks like a 'hump'.

Front 43

What do you need to know about sea turtle hatching?

Back 43

Hatchlings are very small and seldom survive.
Simultaneous hatching of sea turtles (predator saturation).
Imprinting (sea turtles imprint on their natal beach (females return))

Front 44

What are the three primary cues of turtles at different life stages?

Back 44

Light and Elevation Gradient (nest emergence to entering ocean).
Waves (movement away from coastline).
Magnetic field (during migration through North Atlantic Gyre, and homing ability)

Front 45

What are three ways the turtle population is facing risk of extinction?

Back 45

Habitat destruction, pollution, and over-collection for food and pets.