Laboratory Procedures for Primate Osteometrics

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Laboratory Procedures for Primate Osteometrics

Survey of Genetic Traits

• Read these materials BEFORE laboratory day and meet, by phone or Zoom, with the

instructor PRIOR to laboratory if you need clarifications.

• This lab is packed with work.

Scenario

A fire in the primate building of the Philadelphia Zoo during the early morning hours of

December 24, 1995 killed 23 animals, including a family group of six lowland gorillas, a family

group of three orangutans, four white-handed gibbons, and ten lemurs (2 ruffed, 6 ringtail, and 2

mongooses) (see Appendix A).

You were hired to help identify the cranial remains of these fire victims and to preserve them.

The plan is to send them to Skulls Unlimited, Inc. to be replicated. You have taken on this

project, knowing that a portion of the proceeds will be used by the Zoo to help offset the costs of

a new Primate House. Further, a teaching library of primate skulls is not commonly available

except to the major universities. You recognize this project would provide replicas of several

primates that could be made available to the many universities and colleges that do not have a

primate reference library.

Usually trained graduate students are available, but it is Christmas break. You need help with

this work and are short-handed. Luckily, you have identified a group of interested undergraduate

students who are willing to volunteer for this project (for extra credit, of course).

You decide to develop a ‘cheat sheet’ wherein you put the most obvious skull/dental traits. This

cheat sheet can then be used as a starting point for identification of the deceased primate

remains. You have at your disposal an impressive reference library of primate skulls, primate and

non-primate teeth, and dental casting equipment. It is here that you start your training of the

undergraduate volunteers.

Equipment

1) A collection of primate skull photos, and other comparative skull and teeth specimens. [List is located at the bottom of this handout.]

2) Nine (9) tooth and mandible replicas printout 3) Paper rulers [I urge you to use a paper rulers to avoid scratching your computer screen] 4) Printable protractor [I urge you to use a paper protractor to avoid scratching your computer

screen]

Part 1:

Animal Bites Identification

Use Appendices B and C for this part of the lab. Appendix B is a basic description of the nine

animals. Appendix C is a set of drawings for a set of eight (8) jaw fragments and a single tooth

(n = 9). They group into three dietary categories: herbivore, carnivore, and omnivore.

Special Note: If data is not available make as MD (missing data).

• Often, the new student learns from known specimens. This is where you will start.

Primate Osteometrics Procedures 2

• As a first step into the description of teeth, it is important to recognize the 3 categories:

carnivores, herbivores, and omnivores. Read about these species in Appendices B and C.

• Then, complete Table 1 by using a visual examination of the specimens as a guide to your

description of teeth shape as seen in Appendix C.

• Then complete the 3 questions associated with this exercise.

Part 2:

Library of Primate Skull Photos

Each undergraduate student will begin by identifying each primate listed in Table 2.

• When you determine the genus and/or species of the primates you are using for this exercise,

fill in the following blanks. Then, identify the common name and include this information in

Table 2.

• If you can’t identify the scientific name of your specimen go to this website:

http://www.skullsunlimited.com

Part 3:

Primate Skull Comparisons

• Use the list of links at the end of this handout as your specimens.

Measure values directly on your computer screen, using a paper ruler.

• Be aware these specimens are not to scale.

• If you can not perform a measurement due to working on screen or the cranium is

incomplete, mark as MD (missing data).

• I suggest you complete all entries for one specimen before you progress to next.

Complete Table 3A

1. Compare the front of the skull of your primates. To what degree is there facial

prognathism? Determine this by using

two straight edges, a protractor,

Appendix E, and the diagram to the

right.

• First, measure the facial angles for the specimens.

• Second, use the protractor to determine the facial angle. • Third, use a combination of visual observations and your facial angle measurement to

determine values for:

o Orthognathic (straight faced)

o Mesognathic (medium faced)

o Prognathic (jutting face)

Place one straight edge on the Frankfort Plane by aligning M and D (see diagram above):

M Basion Midpoint of the anterior margin of the foramen magnum.

F Nasion The point where the frontal bones and the two nasal bones join.

Place the second straight edge on a place created by G and D (see diagram above):

Primate Osteometrics Procedures 3

G Glabella Between the supraorbital ridges and above nasion, it is the most forward

projecting point of the frontal bone.

D Prosthion On the maxilla, the most anterior point between the upper central incisors. (Do

not confuse with the alveolare).

2. Are there brow ridges? Ranges from “absent”, to “slight” to “moderate”, to “pronounced”. In your notes define these terms.

Complete Table 3B

1. Consider the top of the skull. Is there a sagittal crest? Ranges from “absent”, to “slight” to “moderate”, to “pronounced”. In your notes define these terms.

2. Do you find post-orbital constriction? Read more: orbital_constriction

• Post-orbital constriction index= post-orbital constriction/breadth of braincase (See picture in Appendix E to determine these landmarks)

• In technical terms, the post-orbital constriction index is (frontotemporale to frontotemporale)/(euryon to euryon).

o The technical version generates numerical values.

o Labeled as follows: Pronounced (<0.6); Moderate (0.6-0.7), Slight (0.7-0.8), Very

Slight (>0.8).

Part 4:

Observation of Dental Traits

1. Is there a toothcomb present? Record your data in Table 4.

2. The form of the dental arcade: parallel or parabolic? Record your data in Table 4.

3. It there a diastema? If yes, where is it located and what function might it serve. Record your data in Table 4.

Part 5:

Create your Primate Taxonomy

• Create a taxonomic key to be used by the undergraduates.

• I leave to you to decide which cranial/dental data should be provided to them. These are the

traits you recorded on the data collection handout.

• If you need more traits for your taxonomy, go online and search for primate

characteristics or use your book. If you do so, feel free to use traits other than the skull

(such as “has a tail” and “does not have a tail”).

_____________________________________________________________________________

List of Specimens Used in Parts 3 and 4

Specimen Link

Tree shrew

c83b23f2503443f88815451ad0d15923

Primate Osteometrics Procedures 4

Indri

09791b8a688f455796768cd903f681e1

Mongoose lemur http://skullbase.info/skulls/mammals/mongoose_lemur_-_male.php

Capuchin monkey https://www.folieadeuxdeco.com/osteology/

Potto

dbb114c765b648aab6d4cc436fe96b8c

Cebus albifrons

Skull:

b3c9719e7ce34d6f9274a625f42f4dbd & mandible:

36e567b9971f49a89515ff6fbd88a918

Howler monkey

80243bb86edc4541be150dad368a4d1f

Mandrill Skull:

235a77b3d62947fd9fdc754102b3f8d7 & mandible:

ce7094cd4aff479aa56f4ca0c6cc05ae

Orangutan (male)

8e07519bd4b447b8acfaba8596c41152

Gorilla (male) http://www.digimorph.org/specimens/Gorilla_gorilla/skull/ [Several

pictures on this page, so scroll down]

Chimpanzee http://www.digimorph.org/specimens/Pan_troglodytes/ [Several pictures

on this page, so scroll down]

Human https://free3d.com/3d-model/skull-human-anatomy-82445.html

Name ___________________________________________________________ Anthropology &215

Grading: For each, use X if completed, P if partially completed, and 0 if not attempted.

___ Table 1: Animal Bites (3 points) ___ Part 1: Animal Bites questions (3 points)

___ Table 2 (2 points) ___ Table 3A (2 points)

___ Table 3B (2 points) ___ Table 4 (3 points)

___ Part 5: Taxonomic key (5 points)

_________________________________________________________________________________

Data Collection (Lab)

Table 1: Identification of Nine Dental Specimens by Species (3 points)

Dietary Group Species Name General Description of Teeth Shape1 Dental Formula

Carnivores

African Lion2

Alligator

Coyote

Omnivores

Human

Grizzly Bear

Baboon

Herbivores

Gorilla

Hippopotamus

Beaver

1 Can you determine, from the teeth, whether each species uses puncture-crushing/piercing, shearing, or crush-

ing/grinding when processing their food? 2 Mark MD for any missing data, or look up on the Internet.

Questions

1) Are there similarities in teeth shape that all members of a single dietary group share? (1 point)

2) What clues in teeth shape do you note that suggest the manner by which each dietary group processes its food? (1 point)

3) Does the number of teeth reflect on the food processing behavior of each species? If so, what did you observe? (1 point)

Table 2:

Comparative Library of Primate Skulls

(2 points)

Genus species Common name

Tree shrew ________________ ________________ ________________

Indri ________________ ________________ ________________

Mongoose lemur ________________ ________________ ________________

Capuchin monkey ________________ ________________ ________________

Potto ________________ ________________ ________________

Cebus albifrons ________________ ________________ ________________

Howler monkey ________________ ________________ ________________

Mandrill ________________ ________________ ________________

Orangutan (male) ________________ ________________ ________________

Gorilla (male) ________________ ________________ ________________

Chimpanzee ________________ ________________ ________________

Human ________________ ________________ ________________

Table 3A:

Comparison of Primate Prognathism and Brow Ridge Characteristics

(2 points)

Prognathism Brow ridges

No Yes, to what degree? No Yes, to what degree?

Tree shrew

Indri

Mongoose lemur

Capuchin monkey

Potto

Cebus albifrons

Howler monkey

Mandrill

Orangutan (male)

Gorilla (male)

Chimpanzee

Human

Table 3B:

Comparison of Primate Sagittal Crest and Post-orbital Constriction Characteristics

(2 points)

Sagittal crest Post-orbital constriction

No Yes, to what degree? No Yes, to what degree?

Tree shrew

Indri

Mongoose lemur

Capuchin monkey

Potto

Cebus albifrons

Howler monkey

Mandrill

Orangutan (male)

Gorilla (male)

Chimpanzee

Human

Table 4: Comparison of Dentition (3 points)

Toothcomb Dental arcade Diastema

No Yes No Yes No

If yes,

Location/Function?

Tree shrew

Indri

Mongoose lemur

Capuchin monkey

Potto

Cebus albifrons

Howler monkey

Mandrill

Orangutan (male)

Gorilla (male)

Chimpanzee

Human

Taxonomic Key: Primate Taxonomy (5 points)

Trait (Present or absent) Direction or Scientific name

1A Go to 2A  This is a direction

1B

2A

2B

3A

3B

4A

4B

5A

5B

6A

6B

7A

7B

8A

8B

9A

9B

10A

10B

11A

11B

List of links to specimens (Some are 3D, some a set of pictures)

Specimen Link

Tree shrew https://www.gonzaleztennant.net/3d-hominin-lab/

Indri https://sketchfab.com/3d-models/indri-lemur-skull-09791b8a688f455796768cd903f681e1

Mongoose lemur http://skullbase.info/skulls/mammals/mongoose_lemur_-_male.php

Capuchin monkey https://www.folieadeuxdeco.com/osteology/

Potto

dbb114c765b648aab6d4cc436fe96b8c

Cebus albifrons Skull:

b3c9719e7ce34d6f9274a625f42f4dbd & mandible:

albifrons-mandible-36e567b9971f49a89515ff6fbd88a918

Howler monkey https://sketchfab.com/3d-models/howler-monkey-80243bb86edc4541be150dad368a4d1f

Mandrill Skull:

235a77b3d62947fd9fdc754102b3f8d7 & mandible:

models/mandrillus-sphinx-mandible-ce7094cd4aff479aa56f4ca0c6cc05ae

Orangutan (male)

8e07519bd4b447b8acfaba8596c41152

Gorilla (male) http://www.digimorph.org/specimens/Gorilla_gorilla/skull/ [Several pictures on this page,

so scroll down]

Chimpanzee http://www.digimorph.org/specimens/Pan_troglodytes/ [Several pictures on this page, so

scroll down]

Human https://free3d.com/3d-model/skull-human-anatomy-82445.html

Last Updated on June 22, 2020 by Essay Pro