WILD 3580 1st Edition Lecture 20 Outline of Last Lecture I Order Gymnophiona II Sensory Reception III Reproduction Outline of Current Lecture I Reptiles II Evolution of Reptiles III Classification Current Lecture I Reptiles Characteristics 1 Amniotic Egg 4 extraembryonic membranes a Chorion outer most layer for gas exchange b Amnion contains the amniotic fluid i Creates its own embryonic and aquatic environment to prevent defecation ii Less dependent on water for reproduction c Yolk sac provides nourishment d Allantois gas exchange and waste storage 2 Internal fertilization have copulatory organs a Turtles and crocs penis b Snakes and lizards hemipenes 3 Pulmonary respiration a All reptiles have lungs i Ancestral condition is 2 functional lungs ii Some snakes have only one right functional lungs iii Some turtles softshells can obtain cutaneous respiration through their skin near the cloaca gas exchange These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute II III b Breathing negative pressure ventilation i Creation of a low pressure area by movements of the thoracic cavity ii Snakes and Lizards o Contraction and relaxation of the intercostal muscle rib muscles iii Crocodilians o Contraction of the muscular diaphragm iv Turtles o Specialized muscles on the non shell parts of the body 4 Epidermal scales made of beta keratin a More alpha keratin in the skin impermeable to water 5 Single occipital condyle point articulation where first vertebrates come in contact with skull Evolution of Retiles Began when Osteolepiforms were ancestors of amphibians Formation of occipital condyles and amniote eggs Became part of the diapsid group Synapsid group mammals derived from the opening in the skull fasa indentation increases surface area for attaching jaw muscles o Single temporal opening Euryapsid group single temporal opening higher up in the jaw o Eureptiles early reptiles Anapsid group no temporal openings creating turtles Diapsid group 2 temporal openings leading to modern reptiles Classification Class Reptilia Subclass Archosauria o Order Testudines Turtles anapsids Suborder Cryotidrira hidden necks Suborder Pleurodira side necks not able to retract their heads in the shell Only in the southern hemisphere o Order Crocodylia crocodilians Family Alligatoridae Family Crocodylidae Family Gavialidae Gharials only one living species Subclass Lepidosauria o Order Squamata lizards and snakes Suborder Serpentes snakes Siborder Lacertilia lizards o Order Sphenodontida tuataras lack hemipenes cloaca kiss
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