What information can a forensic anthropologist find from skeletal remains?

First Three Questions: Are the remains actually bone? macroscopic and microscopic study Are the remains Human? appearance and DNA if available Are the Remains Ancient or Modern? look for clothing, historic remains, teeth If human, then proceed to identify the remains Pg 29 Flesh and Bone Read pp XV also

What they can tell… Human or not Modern or Ancient Male or female Age Stature Diseases/Injuries/Conditions Activity level/occupation (hard labor, athlete…) Geographic origin (“race”)

Tissues and Functions of the Human Skeletal System Bone Movement Support Calcium Storage Red Blood Cell Production Protection of Internal Organs

Tissues and Functions of the Human Skeletal System Cartilage In a fetus, skeleton is made of cartilage, later replaced by bone Covers ends of bones (especially at joints) Tendons Connect muscles to bone Ligaments Connect one bone to another bone

What is bone? Organic material (collagen= spongy protein) inside of an inorganic matrix (mostly calcium and potassium) Osteocytes: bone cells

How does bone form and grow? By early twenties, most human bone growth is complete. Osteoclasts circulate and recycle damaged bone cells…”remodeling” Most obvious where bone ends (epiphysis) meet the bone shaft (diaphysis) “growth plate” or “epiphyseal” plate Growth in periosteum (bone cover)

How many bones? About 206- depending on age of person

What kind? Long bones (femur, humerus, radius, ulna, tibia and fibula) Short bones (metacarples and metatarsals—hand bones and foot bones) Flat bones (cranial bones, hip bones, shoulder blades) Irregular bones (vertebra, carpals, tarsals, many cranial bones)

Parts of the skeleton Axial skeleton: Appendicular skeleton: skull (cranium), vertebral column, ribs Appendicular skeleton: Pectoral girdle (scapula and clavicle- forms shoulder) Pelvic girdle (innominate or hip bones) Upper limbs (humerus, radius, ulna, etc) Lower limbs (femur, tibia, fibula, etc)

Axial vs. Appendicular Vizniak, N.A., 2008, Quick Reference Clinical Consultant Muscle Manual, Professional Health Systems Inc, Canada

Forensic Anthropology Defined as the analysis of skeletal remains within a legal investigation Physical Anthropologist = osteologist Training= BS physical anthropology MS osteology

How could anthropologists determine the characteristics that we listed earlier?

Male or Female?

In men, the diameter of the head of the femur is larger than 51 mm In men, the diameter of the head of the femur is larger than 51 mm. In women, the diameter of the head of the femur is less than 45 mm.

Young or Old? Several clues for age (these are only a few): Sutures (skull) Appearance of sutures can give approximate age In infants there are large gaps which close slowly over time There is a particular sequence beginning from the inside of the skull and finishes by age 3 Epiphyseal fusion (think “growth plates”) Most useful for the first 25 years Head of Femur 19 – 20 years Part of hip 24 years Female bones are usually 1-2 years ahead of males in development

Skull Sutures

Cartilage to Bone… (“ossification”)

Epiphyseal Fusion: A General Guide

Fusion of Epiphyses (courtesy of Forensic pathology: principles and practice  By David Dolinak, Evan W. Matshes, Emma O. Lew )

Epiphyses

Teeth (Dentition)

Determining Age Fusion of the vertebra occurs at different times and locations, but is usually complete by age 25.

4 year old Vertebra

30 Year old Vertebra

71 Year Old Vertebra

Geographic Origin

Determination of Race: European Trait Nasal Index: <.48 Nasal Spine: Prominent spine Nasal Silling / Guttering: Sharp ridge (silling) Prognathism: Straight Shape of Orbital Openings: Rounded, somewhat square Orbital openings: round Nasal spine: Prominent Progathism: straight http://upload.wikimedia.org/wikipedia/en/c/cc/Skullcauc.gif

Somewhat prominent spine Determination of Race: Asian (Asian decent and Native American descent) Trait Nasal Index .48-.53 Nasal Spine Somewhat prominent spine Nasal Silling/ Guttering Rounded ridge Prognathism Variable Shape of Orbital Openings Rounded, somewhat circular http://upload.wikimedia.org/wikipedia/en/b/b3/Skullmong.gif

Nasal Silling/ Guttering No ridge (guttering) Determination of Race: African: (everyone of African decent and West Indian decent) Trait Nasal Index >.53 Nasal Spine Very small spine Nasal Silling/ Guttering No ridge (guttering) Prognathism Prognathic Shape of Orbital Openings Rectangular or square http://upload.wikimedia.org/wikipedia/en/5/5e/Skullneg.gif

Maxillae Note shapes of nasal openings… Shovel-shaped incisors Spatulate (flat backed) incisors

Orbital Shapes

Estimation of Stature Intact Corpse – easy Dismembered – must be based on long bones of the corpses Trotter Method – mathematical regression formula based on the Terry collection and hundreds of servicemen from WW II and the Korean War. Regression formula is a set of values that are calculate using measurements of the skeleton.

Determining Stature Ideally all long bones are available for stature determination. Bones are measured using an osteometric board for accuracy. The measurements are then put into standard formulae

Clues to Cause of Death Hyoid Bone Attachment for tongue, mandible, larynx, etc… U-shaped bone in neck Fracture suggests strangulation

Clues to Cause of Death Beveling Cut Marks, Chop Marks, Scrape Marks Exit side is larger in diameter than entrance for a high velocity projectile (bullet) Cut Marks, Chop Marks, Scrape Marks Caused by a tool Gnaw Marks Postmortem- caused by animal activity

Identification of an Individual Dental records Antemortem x-rays (show old fractures, implants, etc) Frontal Sinuses DNA (if possible- in teeth and marrow)

Time Since Death Bones are subject to weathering and scatter. Bodies left on the surface are skeletonized within 8 months. If buried, it will take between 1 and 2 years to become completely skeletonized and in arid areas bodies may become mummified.

Time of Death Scatter is important to the Forensic Anthropologist in estimating time of death and burial. The number and types of bones available at the scene indicates the amount of time the body has been in that spot (smaller bones get lost first). 3 weeks: articulated bones 5 weeks: some scatter, some articulated 4 months: disarticulated, within 10’ circle 7 to 8 months: most bones within 10’ circle and all within 20’ 1 year: small bones missing, complete disarticulation 2 to 4 years: some bones broken, scattered 40’, some large bones missing 12+ years: bone rot

“The Body Farm” Facility instituted at the University of Tennessee by Dr. William Bass Human decomposition is scientifically studied to help us understand decay process as well as how to determine a better estimate of time since death and cause of death

More info on Forensic Anthropology http://www.theabfa.org/ http://whyfiles.org/192forensic_anthro/index.html http://people.uncw.edu/albertm/ http://web.utk.edu/~fac/ http://www.mnsu.edu/emuseum/biology/forensics/ http://www.tncrimlaw.com/forensic/f_anthro.html