Vertebrate Zoology Lab V- Tetrapoda & Amphibia

The major emphasis is on amphibian biodiversity. The goal of this lab is to familiarize you with basic anatomy and diversity among amphibians. Please examine these frogs and salamanders carefully. In order to do so, you will need to take them out of the bottles. Just make certain that specimens are placed back into the bottles from which they came!!!! Drawing pictures and taking notes on characteristics you observe will help you remember these organisms for the practical. See Lab 6 of Gergus and Schuett.

 

Look at the frogs, toads and salamanders in the jars around the room. Make certain that you can identify them and classify them to the level indicated. What are the similarities and differences between frogs and salamanders?

 

Identify the major bones found in the amphibian skeleton. In what ways are the amphibian skeletons similar to those of a fish? In what ways are they dissimilar? Look a the skeleton of the mudpuppy (Necturus; it’s a type of salamander) and notice its posture (the position of the limbs relative to the vertebral column). How does this compare with a frog?

 What modifications in the skeleton of a frog do you observe that might be considered adaptations for jumping?

 

If you were using the frog and salamander as part of a morphological series to study vertebrate evolution, which one would you use to represent a primitive tetrapod? Why?

 

Look at the pictures of primitive tetrapods (amphibians) in the books. In overall morphology, how do these animals compare with modern amphibians? By examining the pictures, determine the number of digits on the feet of Ichthyostega. How many digits are on the feet of modern amphibians? What does this tell you about the structure of the tetrapod limb in terms of its evolutionary history?

 

Know the major characteristics of the taxa: Tetrapoda, Amphibia, Caudata, Anura

 

Know synapomorphies which unite the taxa into monophyletic taxa (Figure 6.1)

 

Know the synapomorphies for the Chordata ,Craniata and Gnathostomata. Be able to identify these structures on any appropriate specimens.

 

In the appropriate specimens, be able to identify the following structures: Atlas, occipital condyle, rigs, pelvic girdle, pectoral girdle, hyoid apparatus, foramen magnum, dentary bone, maxilla, digits, phalanges, metacarpals, metatarsals, humerus, radius, ulna, femur, tibia, fibula, scapula, sternum, tongue, clavicle, quadrate, articular, tympanum, external nares, orbit,

 

Answer questions: Q5, Q6, Q8, Q10, Q11, Q19, Q21, Q22,

 

Skip: Figures 6.2, 6.3, 6.4; Skip pp. 158 (Internal Anatomy) - 165.