Chapter 31 Reptiles & Birds

Evolution Hylonomus (hylo- "forest" + nomos "wanderer") earliest known reptile lived 315 MYA - about 12 inches long - Dinosaurs are reptiles that walked leg below hip and either had: 1.Bird hips (Ornithischia) 2.Lizard hips (Saurischia).

Evolution - Mesozoic Era Earliest known reptile lived 315 MYA / earliest dinosaur 245 MYA

Mesozoic Era 2-7 centimeters a year = 730-2,555cm = m

Dinosaur Evolution

Extinction - 65MYA Adaptive Radiation

Groups of Reptiles & Birds Reptiles 1.Lizards 2.Snakes 3.Crocodilians 4.Turtles & Tortoises 5.Tuataras - primitive scales, no external ears, third eye Birds 1.Song Birds 2.Shore Birds 3.Birds of Prey 4.Wading Birds 5.Sea Birds 6.Game Birds Amphibians 1.Toads 2.Frogs 3.Salamanders Mammals 1.Placental Animals 2.Marsupials 3.Monotremes

Monotremes & Kangaroo

Evolution Reptile: 1.Dry scaly skin 2.Ectothermic 3.Tetrapods 4.Amniotes – terrestrial eggs Birds: 1.Feathers 2.Endothermic 3.Amniotes Amphibians 1.Permeable Moist Skin 2.Tetrapod 3.Four Digits Front & Five on Back Limbs 4.Ectothermic Mammals 1.Produce Milk 2.Have Hair 3.Lower Jaw Single Bone 4.Middle Ear 3 Bones 5.Have a diaphragm 6.Live birth all but.. 7.Endothermic

Avian Skeletal Structure Bones 1.Hollow reinforced with struts 2. Fused collar bone 3. Large keeled sternum Amphibians 1. Reduced or No ribs that do not meet the sternum

Snake Skeleton

Snake Jaws

Scales

Evolution of Feathers

Feathers Contour Feathers Down -Preening -Molting

Movement Types of Flight 1.Straight 2.Hovering 3.Soaring 4.Dive 5.Swimming 6.Landing 7.Take Off

Avian - Respiratory System Air Sacs expand rather than lungs 1. Inhalation - air flows into abdominal and posterior sacs – through lungs 2. Exhalation – air in sacs moves to lungs 3. Inhalation – air in lungs moves to interclavicular, thorasic, & anterior sacs 4. Second Exhalation – air moves out

Reptilian Respiratory System Limited cloacal breathing Lungs are necessary in all reptiles, but filling them is achieved differently. Many reptiles must hold their breath to run as they use the same muscles for breathing and physical effort.

Snake Respiration Snakes breathe by contracting muscles between their ribs. Unlike mammals, they lack a diaphragm.. Inspiration is an active process (muscles contract), whereas expiration is passive (muscles relax). In most snakes the right lung is usually the largest and extends for over a 1/3 of the body. The left lung is then VERY small or absent. Bull Snake Trachea

Snake Digestion During periods of fasting the lining, or mucosa, of the small intestine becomes atrophied, conserving the snake’s energy and resources. Snakes become dormant after large meals and if threatened right after a meal they may regurgitate to escape. Feeding stimulates rapid growth of the intestinal lining and the liver and enters into a period of rapid growth and increased activity.

Digestion Crop - stores & moistens food (crop milk) Gizzard - part of stomach used for grinding hard materials - rocks are often used Stomach Small Intestine Large Intestine

Nictitating Membrane Put in with eye sight