Lecture 27 Flashcards
What was the first component of the tetrapod to evolve
Internal nostrils
How are internal nostrils an adaptation to life on land
They allow tetrapods to breath air through the nose using lung ventilation and to smell outside of water
Why do we have hiccups
In fish the reflex closes the glottis and water is passed over gills w/o entering lungs but in humans there is an abrupt closure of the glottis that causes a hiccup
What are lob fins
Limbs with joints that allow vertebrates to move onto land
What are the 6 challenges of terrestrial life for organisms adapted to aquatic life
- Gravity
- Desiccation
- Respiration
- Reproduction
- Locomotion
- Temperature
G D R R L T
What is a tetrapod
Vertebrate with 2 pairs of skeleton supported limbs & digits
What is Tiktaalik
a transitional fossil linking fishes & tetrapods
What does the shape and size of the pelvis reveal
That fins were capable of a wide range of movements
What are the primitive traits of an Acanthostega (early tetrapod)
-gills, lateral line, long fin rays around the tail
-not weight bearing
What are the derived traits of an Acanthostega (early tetrapod)
-4 limbs with bony digits
-pelvis weakly attached to vertebrate
-primarily aquatic
What are the primitive traits of an Ichthyostega (early tetrapod)
gills, lateral lines
What are the derived traits of an Ichthyostega (early tetrapod)
limbs attached to vertebrate, has weight bearing joints
Characteristics of Class Amphibia
-monophyletic
-thin, permeable skin
-buccal pump
life cycle of amphibians
-external fertilization
-eggs lack shell
-not fully adapted to life on land
What are Anura and Urodela
Anura: frogs
Urodela: Salamanders & newts
