Chapter 17: The Early Tetrapods & Modern Amphibians Flashcards
What types of organisms are considered Amniotes?
Nonavian reptiles, birds & mammals
What are the only living vertebrates that have a transition from water to land?
Amphibians
What is Ontogeny?
Organismal Development
What is Phylogeny?
Evolutionary History
Amphibians are Quasiterristrial. What does this mean?
They hover between aquatic and terrestrial environments and never stray far from water
What is considered the most dramatic event in animal evolution?
The amphibians transition from water to land
List some important physical differences between water and land ( + details) (4)
Oxygen content- more abundant in air.
Fluid Density- air is less buoyant
Temperature Regulation- air fluctuates in temp more than water
Habitat Diversity- amphibians had to evolve in almost every organ system to survive.
The Sporacular Tract in Tetrapods is said to have developed from what structure?
Swim Bladder
What are the 3 groups are Modern Amphibians?
Anurans (Frogs), Salamanders, & Caecilians
In Modern Amphibians aquatic eggs will hatch revealing what? (specific)
Aquatic larvae with gills
During the Metamorphosis of Aquatic amphibian larvae what happens
Gills are lost, and lungs form requiring cutaneous respiration
Modern Amphibians are Ecotherms, what does this mean?
Their body temperature matches environmental temperature
Where are Modern Amphibian eggs laid? Why?
In or near water, to avoid desiccation (drying out)
How many Caecilians are there? Families? Species?
10 families with 215 species
Where are Caecilians located?
Tropical habitats, terrestrial, legless