Anth 125 Introduction to Biological Anthropology
Dr. Darlene Applegate
Spring 2008
GROUP LAB PROJECT 3:
FOSSIL HOMINID IDENTIFICATION
All extinct and extant humans are classified within the family hominidae or hominid . For our purposes, all bipedal apes are considered human ; realize, however, that some researchers consider only extant Homo sapiens as "human" and refer to extinct bipeds as "pre-humans." Two subfamilies of hominids are recognized by most scientists; australopithecines are a diverse and now extinct subfamily and hominins include contemporary humans as well as other species of the genus Homo .
Though consensus is lacking, most paleoanthropologists , or those anthropologists who specialize in the study of human origins and evolution, recognize at least six genera of humans and over 20 species of humans. Instead of learning each of these species, in this introductory course we will group species into only four categories for comparative purposes. Based on skull morphology, we will compare and contrast gracile australopithecines, robust australopithecines, temporally early (about 2.4 to 0.5 mya) hominins, and temporally late (about 0.5 mya to 30 kya) hominins.
The human skull is a collection of almost 30 bones that form a protective covering around the brain and provide a platform for the face and sensory organs. The three main parts of the skull are the cranium (the bones surrounding the brain and the bones comprising the face), the mandible (lower jaw bone), and hyoid (a small, horseshoe shaped bone under the mandible). The portion of the cranium surrounding the brain is the cranial vault or brain case . The four types of teeth in the human skull are the incisors (front four teeth in both the upper and lower jaws), canines (slightly pointed tooth behind the incisors in each quadrant of the mouth), premolars (two broad, two-cusped teeth behind the canines in each quadrant of the mouth), and molars (two-three, five-cusped teeth behind the premolars in each quadrant of the mouth).
Taken as a group, the aforementioned eleven skull traits may be used to distinguish among groups of fossil hominids. Some fossil hominids exhibited ancestral or primitive forms of skull features. For example, robust australopithecines retained a sagittal crest, which is observed in other fossil ape forms such as Miocene apes. Other fossil hominids exhibited derived forms of skull features and therefore more closely resemble contemporary humans. For instance,
The following table provides an efficient means of identifying fossil hominids. Keep in mind, however, that while an individual fossil will have a majority of traits that characterize a particular group, it may not exhibit all expected traits. The images are provided below for comparative purposes.
| TRAIT | GRACILE AUSTRALOPITHS | ROBUST AUSTRALOPITHS | EARLY HOMININS | LATE HOMININS |
| cranial vault | small, elongated | small, elongated | medium sized, slightly elongated to sub-rounded | medium to large sized, sub-rounded to rounded |
| sagittal crest | usually absent, but may be present in males | present | absent | absent |
| post-orbital constriction | moderate | significant | slight | slight |
| brow ridges | large | large | moderate to large | small to large |
| facial profile | very prognathic | very prognathic, concave or "dished in" | less prognathic, may be concave | less prognathic to orthognathic |
| cheek bones | moderate | large and broad | moderate | small to moderate |
| nose | non-projecting or flat | non-projecting or flat | slightly projecting | projecting |
| mandible | large | very large | moderate | small to moderate |
| canine teeth | large. slightly projecting | large, non-projecting | small, non-projecting | small, non-projecting |
| molar teeth | large, broad | very large and broad | moderate size | moderate to small size |
| projecting chin | absent | absent | absent | may be present |
Figure 1. Front and side views of two gracile australopithecines.
Image from http://fossils.valdosta.edu/fossil_pages/fossils_ter/p22.html
Figure 2. Front and side views of three robust australopithecines.
Images from http://www.hofesh.org.il/articles/science/branches.html
http://peinandoelmono.tripod.com/galeria_a.htm
Figure 3. Front and side views of two early hominins.
Images from http://www.msu.edu/~heslipst/contents/ANP440/rudolfensis.htm
http://www.boneroom.com/casts/images_hominid/
Figure 4. Front and side views of three late hominins.
Images from http://posters.sonik.us/details/this-neandertal-skull-from-wadi-amud-is-about-60000-years-old-1008584.html
http://www.kalyx.com/store/images/SD_0269.jpg
http://www.paleodirect.com/bh004.htm
The fossil hominid identification assignment will be completed in class by students working in groups. Each student in the group will complete his/her own answer sheet in pencil.
Examine each of the eight skull specimens. Using the information provided in this lab overview as well as in class lecture and the textbook, identify the type of hominid and record the answer clearly on the answer sheet. Do not provide more information than what is requested.
Each group will have about five minutes to work with each specimen.
