1. Comparative Animal Morphology Lab Days
Introduction to Vertebrate Morphology

2. Introduction
Morphology is the study of an organism’s internal and external anatomy.
A complete morphological overview would also include a look at the evolutionary origins of anatomical features in the invertebrate groups. However, the diversity of inverts makes this difficult.
By studying the anatomy of animals we can determine their evolutionary relationships.
For example, to determine the history of development and function of the mammalian lung we look at its origin in the swim bladder of bony fishes.

3. Intro. Cont.
To make this comparison meaningful and possible we will focus on four chordate animals; the lamprey, the dogfish shark, the mudpuppy, and the cat.
This will introduce you to animals that play an important role in interpreting the developmental history of vertebrates.
Each specimen chosen for this study is the result of millions of years of evolutionary adaptation to their current environments.

4. The Lamprey
An example of the morphology found in the earliest vertebrates.
Has evolved some highly specialized structures that allow it to function as a member of the modern fish fauna.

5. Dogfish Shark
A gnathostome, jawed vertebrate, in which we will see a combination of ancestral and derived structures.
Much of the ancestral anatomy foreshadows anatomical conditions found among the tetrapods.

6. Mudpuppy
A tetrapod, four-legged vertebrate, whose anatomy is predominately ancestral with specializations that allow it to function as a viable obligate aquatic vertebrate.

7. Cat
A mammal that exhibits a body plan that is relatively unspecialized and similar to our own.

8. What is a chordate?
The relationship among animals have been, and remain, a major point of interest among biologists.
2 distinct groups of animals have evolved; protostomes and deuterostomes.
The major reason they can be indentified is based on events that occur during embryonic development. Early cleavage in both leads to the formation of the blastula.
Protostomes: blastopore forms the mouth
Deuterostomes: blastopore forms the anus

9. Chordates Cont. All chordates are deuterostomes.
All possess certain characteristics at some time during their life that may persist into the adult form.
These include:
The notochord
A dorsal hollow nerve cord
Pharyngeal gill slits
A subpharyangeal organ (Endostyle or Thyroid)
A post anal tail

10. Anatomical and Directional Terms
To comprehend the dissection instructions and become a “literate anatomist” you must understand the language of anatomy.
In this lab you will be expected to pronounce and recognize anatomical and directional terms. (However, I will not count off for spelling on exams and quizzes if I know what you are trying to say)

11. General Directional Terms
Dorsal-Ventral
Cranial-Caudal
Anterior-Posterior
Medial-Lateral
Distal-Proximal
Transverse-Sagittal-Frontal

14. END