 Ectothermic  Dry body covered with scales  Keratin  Toes have claws  Well developed lungs  Heart is 3-chambered  Internal fertilization  Amniotic egg

 Order Testudinata (Chelonia) - turtles  Order Crocodilia - crocodiles and allies  Order Squamata - snakes and lizards

 Shell  Cryptodira: “hidden-necked” turtles which retract their necks into the shell  Pleurodira: “side-necked” turtles which wrap their heads around the side of the shell

 Tetrapods  Head (with a neck)  Beak  Shell: connected by a bridge  Carapace  Plastron  Scutes  Tail  Ability to pull head, neck, limbs, tail into shell

Carapace Scutes Neck Head Tail Plastron Beak Where would the bridge be found?

 Internal AND external skeleton  Vertebral column fused to the carapace (and limb girdles)

 Skull  Mandible

 Proscapular process  Coracoid  Scapula  Humerus  Radius  Ulna  Metacarpals  Phalanges

 Vertebrae  Pelvic girdle  Femur  Tibia  Fibula  Tarsals  Metatarsals  Phalanges

 Very similar to humans  Deltoid (retraction of forelimbs)  Pectoralis major (retraction of forelimbs)  Triceps  Biceps  Latissimus Dorsi  Gastrocnemius  Gluteus (retraction of hindlimbs)

 Retrahens capitis collique  Retracts head and neck into the shell  Flexor caudae lumbalis  Flexor caudae obturator  Draw tail in

 Some predaceous, some herbivorous  Beak  Mouth and Tongue  Excretion of some digestive enzymes in saliva to begin digestive process  Turtles swallow large pieces of food

 Esophagus  Tubular  Connects mouth and stomach  Stomach:  Digestive enzymes and acids within decompose the food  Walls of the organs in the digestive system are composed of smooth muscle  Push the food through the system  Aids in decomposition of the food by churning during the digestive process

 Liver is the largest organ in the body of a turtle.  Bile production  Gall bladder  Pancreas: sliver like gland located next to the small intestine  Aids in the digestive process by introducing digestive enzymes into the small intestine

 Small and Large Intestine  Villi located on the small intestine wall absorb nutrients  Duodenum  The large intestine absorbs water  Anus

 Breathe through lungs  Mouth and Cloaca  Respiration through nose and mouth  When oxygen levels are low, some turtles have the ability to take in oxygen through their cloaca

 Glottis, Larynx, Trachea  The glottis of the turtle is a small opening positioned behind the tongue.  It acts like a barrier between the mouth and the larynx. The larynx is leads to the trachea.

 Trachea – connection between larynx and bronchii  Bronchii  Connect trachea to lungs

 Lungs  Directly under the turtle's carapace  Bronchii break into tinier tube like structures called bronchioles.  The bronchioles then continue the pattern, leading to the alveoli Alveoli greatly increase the internal surface area and increase the efficiency of the lungs.

 Three chambered heart  2 atria  1 ventricle Partially divided – septum  Surrounded by a pericardium

 Sinus venosus  Pulmonary arteries and veins  Systemic arteries and veins  Aorta

 Left atrium  Ventricle  Right atrium  Sinus venosus  Systemic arteries  Systemic veins  Pulmonary arteries  Pulmonary veins  Lungs  Body  Aorta

 Olfactory nerve  Olfactory lobe  Cerebrum (in hemispheres)  Pineal gland between the two hemispheres on dorsal surface  Ventral surface: hypothalamus and pituitary gland: hormones; regulation of body  Optic lobe  Choroid Plexus: secretion of cerebrospinal fluid  Cerebellum  Medulla oblongata

 Kidney  Ureters  Urinary bladder (with accessory bladders)  Cloaca

 Internal fertilization  Amniotic organisms  Egg is better adapted for life on land  All oviparous with no parental care  Females:  Ovary  Oviduct  Male:  Testes  Epididymus  Penis

 Turtles lay eggs outside of the water  Bury in sand, dirt  Typically near a body of water  Incubation temperature depends on species  Egg shells can range from soft and leathery to hard and brittle

 Shell to prevent desiccation  Amnion – encloses embryo within the egg  With amniotic fluid  Allantois – gas exchange, waste excretion  Chorion – gas exchange  Yolk sac – nutrition