Turtles Flashcards
What are the 2 lineages of turtles?
Cryptodires and pleurodires
What defines a cryptodire?
They retract the head into the shell by bending the neck in a vertical S shape. Largest group (include aquatic and terrestrial)
What defines a pleurodire?
They retract the head by bending the neck horizontally. Only found in southern hemisphere. All species at least partially aquatic.
What is the birth type and parent care of turtles?
All lay eggs and none exhibit parental care after hatching
Can turtles have rapid population growth?
Not usually, they are long-lived
Why are turtles a conservation concern?
- sex is determined by temperature of the embryos
- they have a poor capacity for rapid population growth
What kind of bodies do terrestrial turtles have?
High domed shells, elephant-like feet (or spade-like for burrowing)
What kind bodies do box turtles have?
Flexible regions of plastron (lower shell), which allow front and rear lobes to be pulled upward to close the openings of the shell
What body type does the African pancake tortoise have?
Flat, flexible shell with reduced ossification. It wedges itself into rock crevices to avoid predation
What kind of bodies do aquatic turtles have?
Low carapaces (upper shells) that offer little resistance when moving through water
What type of shell do snapping turtles and mud/musk turtles (all cryptodires) have? Why?
They are less streamlined because they prowl bottoms of ponds and slow rivers. They also have reduced plastrons (makes them more agile)
What do snapping and musk turtles use for protection?
Strong jaws
Cryptodires are apparently soft-shelled turtles. Why do they have reduced ossification?
They want a lighter shell to be a fast swimmer (feet are large and webbed as well)
What type of predators are most cryptodires?
Ambush predators (long neck allows them to reach out to seize prey)- stay partly buried in debris in ponds to wait
Snake-necked turtle (pleurodire) have what kind of adaptation for feeding?
Long slender necks to catch fish with a sudden dart of the head
What are the adaptations of the matamata of South America?
Highly camoflauged- flaps of skin on head are highly sensitive to vibrations of fish prey. They abruptly open mouth and expand throat to suck in prey.
Which of the 2 groups of turtles are marine turtles?
Cryptodires
What is the largest marine turtle and some facts about it?
The leatherback (2m long). Has a larger distribution than any other ectothermal amniote. Dives more than 1000m. Feeds on jelly fish.
What are the 3 hypotheses for turtles’ phylogenic position?
- origin among parareptiles, sister group of reptiles
- sister group of lepidosaurs
- sister group of archosaurs
What is the basic structure of a turtle?
Shell is dermal bone (59 plates). Ribs are fused to shell and are external to girdles. Limbs are inside ribs and they have horny beaks instead of teeth
How do turtles breathe?
Lungs are attached to the carapace dorsally and laterally. The weight of the viscera keeps the diaphragmatic sheet stretched downward. Turtles produce pressure changes in lungs by contracting muscles- inhalation and exhalation require this
What type of respiration does the Australian Fitzroy River turtle use?
Cloacal respiration:
- orifice is 30mm in diamter. Turtle holds cloaca open, large sacs open from the wall of the cloaca and have many villi.
- Turtle pumps water into and out of the sacs 15 times per minute. rarely needs to surface to breathe
How long do small species vs large species live?
Small turtles live 7-14 years. Large tortoises and sea turtles live at least as long as humans
Are turtles endo- or ecto- thermic?
mainly ectothermic
