Amphibians are vertebrate tetrapods. Amphibia includes frogs, salamanders, and caecilians. The term amphibian loosely translates from the Greek as “dual life,” which is a reference to the metamorphosis that many frogs and salamanders undergo and their mixture of aquatic and terrestrial environments in their life cycle.

Amphibians have several adaptations that allow them to live on land:

large shoulder and hip bones
a muscular tongue
a middle ear
they can breathe through their skin or with gills or lungs

However because amphibians lay eggs, they are reliant on water to reproduce. They use several strategies to keep their eggs moist:

lay eggs directly in water
lay eggs on moist ground
wrap eggs in leaves

Start by watching this series of five Animal Planet videos:

Figure 1. The recent fossil discovery of Tiktaalik roseae suggests evidence for an animal intermediate to finned fish and legged tetrapods. (credit: Zina Deretsky, National Science Foundation)

Complete the tasks on the list below:

Go to this page, http://cnx.org/contents/GFy_h8cu@10.53:TIORyfla@5/Amphibians, and read the entire page
The QR codes on the page that link to the following, be sure to take the time to visit each link below, or use the QR codes on the page.

River Monsters - Fish with Arms and Hands?
Earth's Paleogeography: continental Movements Through Time

Use the Glossary at the bottom of the page to help with the vocabulary for this week
Use the Review Questions and Free Response questions to check for understanding
Read more about the life cycle of frogs on the Biology Resources page, Frogs - an Introduction

Download for free at http://cnx.org/contents/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.53