L15: Class Reptilia (including birds) Flashcards
Identify adaptations that allowed reptiles to further abandon aquatic environments Describe the amniotic egg and explain its significance Indicate why the traditional taxonomic arrangement of vertebrate classes (reptiles, birds, mammals) is problematic Identify the distinguishing features of birds Identify features that ally birds to reptiles Describe anatomical features of birds that are associated with flight Describe unique features of the avian respiratory system
Identify 7 features of how amniotes continued to adapt to terrestrialism
- Amniotic egg (4 membranes)
- Water-resistant skin
- Claws (keratin)
- Enhanced neck mobility
- Limb articulation
- Efficient kidneys
- Efficient respiratory system
What are the four membranes of the amniotic egg
Amnion
Chorion
Allantois
Yolk sac
What is the function of the Amnion
encloses the embryo in a fluid-filled sac and protects against
shock and desiccation
What is the function of the Chorion
nearer the shell and becomes
highly vascular and aids in gas exchange
What is the function of the secondary palate
Separates nasal and oral cavities
What is the function of the Allantois?
stores nitrogenous wastes
Why are fenestrae beneficial
Allow for increased muscle mass, and therefore a stronger biting force
Describe acrodont teeth vs pleurodont vs thecodont teeth
Acrodont: rootless teeth, in fish, amphibians, snakes some lizards
Pleurodont: Not in sockets, attached to medial edge. In most lizards
Thecodont: Teeth set into deep sockets. In humans
What is an akinetic skull
Upper jaw firmly attached to skull, low mobility of the upper jaw
Describe order Squamata
Lizards/snakes
Kinetic skulls - more upper jaw movement
Lizards and legless lizards, snakes
Describe the carapace in Testudines (turtles)
Fusion of ribs, vertebrates and dermal bones
The upper shell
Describe the plastron of Testudines (turtles)
Lower shell, fused pectoral girdle and dermal bones
T/F Testudines (turtles) have thecodont teeth
False - they have no teeth! Just a keratin beak
Describe Crocodylia
Thecodont teeth
Nonprotrusible tongue
Laterally compressed, muscular tail
Four chambered heart, diaphragm
What animals are in the Archosaurs
Chrocodylia, dinosaurs, birds
What are the two lineages of birds. Briefly describe them
Paleognathae: Large, flightless birds
Neognathae: everything else
What are some general features of birds?
Similar anatomically to reptiles
Sole group of amniotes that have feathers
Skeletal features associated with flight
Endotherms with high metabolic rate
Highly efficient respiratory system
Bill made of keratin, no teeth
Internal fertilization and hard shelled eggs
Extended parental care for young
What are the similarities of avians to reptiles?
Single middle ear bone
Single occipital condyle that articulates with 1st vertebrae
Air spaces in bones
Nucleated red blood cells
Feathers (primitive reptiles had feathers)
Extended nesting/parental care
Muscular gizzard (food grinfer in digestive tract)
What are Theropods?
Dinosaur ancestors of birds
Walked on two feet (bipedal)
Light, hollow bones
Carnivorous
Many had feathers
What are the two kinds of feathers and their function
Pennaceous - flight/contour
Plumulaceous - keeping warm
Describe pennaceous feather anatomy
Keratin shaft that grows out of skin, with side barbs that have barbules with little hooks that interact and keep feather flat and intact
T/F: Plumulaceous feathers have no barbules
True! Have barbles, but no barbules
Describe how birds have a skeleton built for flight
Light, long bones
Simple skulls
Uncinate process that reduces trunk/middle flexibility
Furcula (fused clavicals) that reduces movement
Expanded sternum for muscle attachment
Long pelvis to reduce flexibility
Fusion of wrist/hand bondes and caudal vertebrae (fewer bones)
What is the function of the Alula?
Little wing thing that reduces air turbulence so they can fly slowly but still maintain lift
Describe bird respiratory systems
Lungs are arranged so air flow is in one direction
Thin-walled sacs in thoracic and abdominal areas
No respiratory dead space, very efficient.
