BIO270 Laboratory Guide #4

 

SKULL AND DENTITION; OSTEOLOGY;

TAXONOMIC KEYS

After completing this laboratory you should be able to:

 

1)   Identify the chondrocranial, dermatocranial, and splanchnocranial components in any vertebrate skull;

 

2)   Identify the specific skull structures in the list in Part I;

 

3)   Identify the dentition type for any vertebrate specimen;

 

4)   Produce the dentition formula for any heterodont mammalian specimen;

 

5)   Recognize endochondral and intramembranous bone formation in histological slides and specify in which bones each process occurs;

 

6)   Identify the common regions and structures in mammalian long bones and teeth;

 

7)   Apply taxonomic keys to classify vertebrate specimens.

 

 

 

 

 

 

 

 

 

 

 

 

 

shark chondrocranium

 

 

 

 

 

 

 

Necturus skull

 

 

Salamander Skull Guide

 

 

 

 

cat skull

 

 

 

 

 

 


  

I.  SKULL

 

1.    Work through the latter half of KZ Chapter 5 (pages 65-81) dealing with skulls. 

 

2.   Focus on the shark chondrocraniums, shark jaw set, Necturus skulls, and cat skulls.  For each of these animals be able to recognize structures from the list below which are labeled in the figures and underlined in the text. 

 

Structures to identify:

   

    Shark:

  chondrocranium

      rostrum

          rostral carina

          precerebral cavity

          rostral fenestrae

       nasal capsules

          nares

          orbits

               supraorbital crest

           otic capsules

           occipitum

               occipital condyle

               foramen magnum

     splanchnocranium

           mandibular arch

               upper jaw

               lower jaw

                    Meckel's cartilages

                    labial cartilage

            branchial gill arches

 

  

     Cat:

          general features

         orbits

          external nares

           cranium

                 cerebral fossa

                 cerebellar fossa

                 tentorium

                 temporal fossae

                 foramen magnum

                  sella turcica

           external auditory meatuses

            tympanic bullae

      bones and bony structures

             nasals

             premaxillae

             maxillae

             frontals

                  frontal sinus

             parietals

             interparietals

             occipital

                  occipital condyles

             jugal (zygomatic)

             lacrimals

             temporals

                 tympanic bullae

             turbinates

             palatines

             vomer

             ethmoid - cribriform plate

             sphenoid set

                 sphenoidal sinus

             mandibular set

                   (lower jaw -

                     several fused bones)

               hyoid apparatus

 

 

 

Necturus:

     dermatocranium

            premaxillae

            frontals

            parietals

            quadrates       

            vomer

            pterygoids

            parasphenoid

            dentary

       chondrocranium

             ethmiod plate

             exoccipitals

             foramen magnum

             otic capsules

       splanchnocranium

             (hyoid elements are not

             present on our specimens)

 

  

3)   For the other vertebrates in the lab manual, be able to distinguish chondocranium, dermatocranium, and splanchnocranium contributions to the skull.

 


 

II.  DENTITION

 

1)   Work though the dentition section of KZ Chapter 5 (pages 81-83).

 

2)   Work with the sample skulls to find examples of each of the following dentition types:

 

          

adont vs. diphyodont vs. polyphyodont

acrodont vs. pleurodont vs. thecodont

homodont vs. heterodont

 

 

3)   For each of the heterodont mammalian skulls determine the dental formula: I/I,C/C,P/P,M/M.  The examples to the left show the upper and lower jaws of a lion, with the dental formula 3/3,1/1,3/3,1/0.

          

 

  

III.  BONE AND TOOTH STRUCTURE AND DEVELOPMENT

 

1)   Work through the slides of hyaline cartilage, elastic cartilage, fibrocartilage, and compact bone until you can recognize these tissues.

 

2)   Work through the demonstration slides of endochondral and intramembranous bone development.

 

3)   Identify the labeled structures on the long bone samples.

 

4)   Examine the demonstration slide of mammalian tooth structure, using the card and the diagram link to the left as guides.

 

 

 

  

IV.  TAXONOMIC KEYS

 

1)   Classify at least two of the sample mammalian skulls to the level of Genus using the Roest guide.

 

2)   Classify the same two sample mammalian skulls to the level of Genus using the Jones and Manning guide.

 

3)    How well do your two sets of classifications agree?