ANTH 351 Sexing Lab- Osteological Lab 2

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Name: Alyssa Jordon Anthropology in Forensic Investigations: ANTH 351 Osteological Lab 2: Sexing Human sexual variation is not neatly divided into female and male types; it is better visualized as an overlapping set of normal curves with considerable tails. Many people fall within the area of overlap and some fall in the tails. As a result, in order to properly determine the sex of skeletal remains, the more indicators used, the more accurate the results will be. (Burns 2007, 202) Instructions: You will be using listed characteristics from the pelvis, cranium, femur, and humerus to determine sex of an unidentified individual. Since the class is completely online, I supplied you with descriptions of the skeletal remains that are used for this lab since I am not allowed to take pictures of them for your use in this lab. I apologize for this inconvenience. Remember to completely fill in the table, document your final sex determination, and answer the short essay question. I. PELVIS Note : For each of the pelvic characteristics/landmarks being assessed, I have kept the instructions that you would use if you had the skeletal remains in front of you to assess so you can understand how a forensic anthropologist would process with their analysis. After each set of instructions and questions you would answer, I have supplied a description of the pelvic characteristics/landmarks being assessed. 1. Determine the sub-pubic angle by using the following method: Place the two os coxa together at their pubic symphyses and place the sacrum between them to provide the actual shape of the pelvis. Is the angle of the area just below the pubic symphyses (with the ischiopubic rami as the sides of the angle) lesser or greater than 90 degrees? Is the shape of the area (sub-pubic concavity) U-shaped (concave) or V-shaped (convex)? Record your results in Table 1. Description of Sub-pubic angle: Less than 90°; U-shaped (concave) 2. Locate the greater sciatic notch and use the following method to assess its angle. Place your thumb within the greater sciatic notch. Is there a good amount of space between the sides of the greater sciatic notch and your thumb? If yes, then it is wide. If not, it is narrow. Is the greater sciatic notch deep or shallow? Record your results in Table 1. Description of the Greater sciatic notch: Moderately wide and deep 3. Is there a noticeable groove at the lower edge of the auricular surface, known as a preauricular sulcus? Record your results in Table 1. Description of the Pre-auricular surface: Absent on Left; Present on Right 4. Is there a ridge of bone on the lower edge of the ventral surface of the pubis, known as a ventral arc? Record your results in Table 1. Description of the Ventral arc: Present 5. Is the bone area uniting the ischium and pubis, known as the ischiopubic ramus, narrow and stretched or wide? Record your results in Table 1. Description of the Ischiopubic ramus: Narrow and “stretched”

II. SKULL Note : When viewing the skull from the front or side, always have the skull oriented so that it is anatomically correct, i.e., the eye sockets should be parallel to the table top, and not directed upwards. This is known as the Frankfort Horizontal Plane. For the characteristics that have possible areas to assess on each side of the skull, examine both and record your observations (if they are the same, only record the observation once; if they are different, record both observations). 1. Above the eye sockets, run your fingers along where the eyebrows would be located. Does this area of bone stick out more forwardly than the forehead or is it smooth and show no forwardly projection? Record your results in Table 2. Description of the Supraorbital ridge: Absent 2. Run your finger over the upper edge of the eye orbit, known as the upper orbital margin. Is it rounded or sharp? Record your results in Table 2. Description of the Upper orbital margin: Sharp 3. Is the forehead (frontal bone) vertical or sloping (directed more posteriorly)? Record your results in Table 2. Description of the Forehead: Vertical forehead 4. Locate the mastoid processes (protruding bone posterior to or behind both ears). Are they large or small in size? Record your results in Table 2. Description of the Mastoid processes: Small 5. Locate the zygomatic processes (ridge of bone connected the zygomatic bone to ear area). Are these ridge extend beyond the external auditory meatus or end at it? Record your results in Table 2. Description of the Zygomatic processes: Ends by the External Auditory Meatus 6. Locate the nuchal lines (curved lines) of the occipital bone. Are they slight or strong sites of neck muscle attachment? Record your results in Table 2. Description of the Nuchal lines: Slight to moderate muscle attachment sites 7. Locate the external occipital protuberance. Is it prominent (large) or less prominent / absent? Record your results in Table 2. Description of the External occipital protuberance: Less prominent 8. Locate the mandibular (ascending) rami. Are they narrow and are their gonial angles obtuse or wide with more straight (closer to 90°) gonial angles with flared edges? Record your results in Table 2. Description of the Mandibular rami: Wide but obtuse gonial angles, flared angles 9. Locate the chin on the mandible. Is it square or round (oval) in shape? Record your results in Table 2. Description of the Chin: Rounded III. FEMUR 1. Using the spreading calipers, measure the maximum vertical diameter of the femoral head in (mm). Measure both femoral heads and record their measurements in Table 3. Maximum Vertical diameter of femoral head: 40 mm if White, 40 mm if Black IV. HUMERUS 1. Using the spreading calipers, measure the maximum vertical diameter of the humeral head in (mm). Measure both humeral heads and record their measurements in Table 4. Maximum Vertical diameter of humeral head: 38 mm V. FINAL DETERMINATIONS Note: Remember that all of the bones used to assess sex should be looked at as a whole. For example, if the majority of the bones used to determine the sex indicate that the individual was male, then your final determination of sex should be male. Use one of the following sex determination categories for your final determination: Male, Probable Male, Indeterminate, Probable Female, and Female . 1. Based on your results entered in Tables 1-4, make a final determination as to the sex of this individual. Write this answer in the space provided below Table 4.

SEX DETERMINATION Table 1 – Pelvis Trait Result Female Male Sub-Pubic Angle Less than 90 degrees = MALE > 90 degrees < 90 degrees Sub-Pubic Concavity U-shaped (concave) = FEMALE U-shaped (Concave) V-shaped (Convex) Greater Sciatic Notch Angle Moderately wide = FEMALE Wide Narrow Greater Sciatic Notch Depth Deep = MALE Shallow Deep Preauricular Sulcus No preauricular surface present on the left, but present on the right = INDETERMINATE More Commonly Present More Commonly Absent Ventral Arc Presence of the ventral arc = FEMALE Present Absent Ischiopubic Ramus Ischiopubic ramus was stretched and narrow = FEMALE Narrow, “Stretched” Wide Table 2 - Skull Trait Result Female Male Supraorbital Ridge Absent = FEMALE Absent Prominent Upper Orbital Margin Sharp = FEMALE Sharp Rounded Forehead Position Vertical Forehead= FEMALE More Vertical Forehead More Sloping Forehead Mastoid Process Small= FEMALE Small Large Zygomatic Process Length Ends by the External Auditory Meatus = FEMALE Ends by the External Auditory Meatus Extends Beyond the External Auditory Meatus Nuchal Lines (Occipital) Slight to Moderate Muscle Attachment Sites = FEMALE Slight Muscle Attachment Sites Strong Muscle Attachment Sites External Occipital Protuberance Less Prominent = FEMALE Less Prominent or Absent Heavier and More Prominent Mandibular Ramus Wide, but obtuse gonial angles, flared angles = INDETERMINATE Narrow, Obtuse Gonial Angle Wide , Straighter (~90° Gonial Angle), Flared Edges Chin Shape Rounded = FEMALE Rounded or Pointed Square, Protuberant Table 3 - Femur Trait Result Female Female? Indeterminate Male? Male Maximum Vertical Diameter of Femoral Head (mm) if White 40 mm (White) = FEMALE < 42.5 42.5 – 43.5 43.5 - 46.5 46.5 – 47.5 > 47.5 Maximum Vertical Diameter of Femoral Head (mm) if Black 40 mm (Black) = FEMALE < 40 40 – 43 43 – 44 44 – 47 > 47 Table 4 - Humerus Trait Result Female Probably Female Indeterminate Probably Male Male Maximum Vertical Diameter of Humeral Head (mm) 38 mm = FEMALE < 43 43 - 44 44 - 46 46 - 47 > 47 FINAL SEX DETERMINATION: FEMALE

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