ANT 3514- Introduction to Biological Anthropology

ANT 3514- Introduction to Biological Anthropology Pliocene Hominids Lab 8, Week of 03/01/04

REVIEW your textbook (chapters 6 and 7) and articles in your reader to prepare you for this week’s lab. READ over this entire download to familiarize yourself with this week’s stations. TERMS at the end of this download will assist you with this lab.

THE FOCUS of this week’s lab is to understand morphological characteristics associated with early hominid taxa. This is best accomplished by comparison of the fossil material with skeletal material representing Homo sapiens and modern apes.

Familiarize yourself with the fossil material as best you can. Learn specimen designations for key fossils, key sites, dates for key sites, genus and species recovered from key sites, etc. You will also need to know some of the important anatomical characteristics that characterize particular genera and species. Understanding specimen designations will assist you in remembering geographic distribution. (See the last page of this download for some information regarding specimen designations.) NOTE: Not all the fossil taxa of early hominids for which you will be responsible on your next exam are represented in this lab. It is strongly recommended that you review chapters 6 and 7 carefully in your textbook. Although this lab will not be due until the following week, it would be to your benefit to try to complete the following table before coming to your lab section. Don’t panic if you can’t complete the table. Not all species listed have a known cranial capacity.

Pliocene Hominids Hominid Date Range Cranial Holotype Geographic Capacity Distribution Kenyanthropus platyops Australopithecu s afarensis Australopithecu s africanus Australopithecu s anamensis Paranthropus boisei Paranthropus robustus Paranthropus aethiopicus Ardipithecus ramidus Sahelanthropus tchadensis Orrorin tugenensis Useful websites: www.talkorigins.org/faqs/homs Click on hominid fossils and type specimens under table of contents www.modernhumanorigins.com/hominids.html !!!PLEASE HANDLE THE LABORATORY MATERIAL VERY CAREFULLY!!!

STATION 1 – Kenyanthropus platyops

This station focuses on an early hominid species known as Kenyanthropus platyops, in particular the craniodental differences between K. platyops, modern apes, an Australopithecus species and an early Homo species (H. habilis) which will be discussed in more detail in a later lab. At this station you will find:

 a cranium of Kenyanthropus platyops (KNM-WT 40000 – the holotype for K. platyops)  a skull of Pan troglodytes  a skull of Homo habilis (KNM-ER 1813)  a partial cranium of A. africanus (A73)

Kenyanthropus platyops is an early hominid species recently discovered in 1999 west of Lake Turkana (Kenya). Fossil material representing K. platyops date to approximately 3.5-3.0 MYA. The holotype for K. platyops presents a unique combination of derived facial and primitive neurocranial features. These findings may indicate an early diet-driven adaptive radiation of early hominids.

(in class) Describe the following cranial features of K. platyops relative to the chimpanzee and early Homo:

Chimp K. platyops Early Homo Postorbital constriction

Shape/Morphology of Face (degree of prognathism) Dental Features

STATION 2 – Australopithecus afarensis (cranium) (pgs. 247-258 in your textbook)

This station focuses on craniodental features of A. afarensis as compared to modern apes and humans. At this station you will find:  a chimpanzee cranium and mandible  a modern human mandible and cranium  a composite cast of A. afarensis  3 partial jaws of A. afarensis o LH 4 (an adult mandible – the holotype for A. afarensis) o LH 2 (a juvenile mandible) o LH 5 (a fragment of an adult maxilla) (in class) How are each of these features similar and different between these species?

A. afarensis Chimpanzee Modern Human Dentition/ Palate Shape

Morphology of face/ Zygomatic Bone

Brow Region

Degree of Prognathism

(at home) What did A. afarensis mainly eat?

STATION 3 – Australopithecus afarensis (postcranium) (pgs. 247-258 in your textbook)

This station focuses on features of the foot of A. afarensis as compared to modern apes and humans. At this station you will find:

 an articulated chimpanzee foot  an articulated human foot (at the bottom of a skeleton)  2 impressions of the Laetoli footprints

The Laetoli footprints were made by two hominids 3.6 MYA in Laetoli, Tanzania. These footprints have great implications for evidence of habitual bipedal locomotor patterns in early hominids.

(in class) Based on information regarding the differences between ape and human feet provided in your textbook and in lecture, discuss the morphological features of the feet that likely made these footprints. Be sure to mention specific features and how these features compare to apes and humans. What do these features imply regarding the type of bipedalism practiced by A. afarensis (was it similar to the way humans practiced bipedalism)?

(at home) Go to http://www.mnh.si.edu/anthro/humanorigins/ha/laetoli.htm and answer the following question: How and why were the footprints formed and preserved?

STATION 4 – Bipedalism

In the previous station foot morphology was studied in relation to bipedalism, but there are other morphological indicators of bipedalism as well. At this station you will find:  an articulated pelvis of Pan troglodytes  an innominate and sacrum of A. afarensis (“Lucy”)  an articulated pelvis of H. sapiens  a femur of H. sapiens  a femur of A. afarensis (“Lucy”)  a femur of Pan troglodytes

(in class) How do the pelves and femora differ between these three species? A. afarensis Chimpanzee Modern Human Pelvis Morphology- (sciatic notch, orientation of iliac blades, etc.)

Femur Morphology- (femoral neck, femoral head size and shape, etc.)

(at home) How do these different morphological features affect bipedalism? STATION 5 – Australopithecus africanus (pgs. 206-213, 216-222 in your textbook)

This station focuses on craniodental and pelvic features of A. africanus as compared to modern apes and humans. At this station you will find:  a human cranium and mandible  a chimpanzee cranium and mandible  2 adult cranium of A. africanus (A5 and A72)  a juvenile cranium of A. africanus (Taung – “The Taung Child”)

(in class) How do each of these features differ (or are similar) between these species?

A. africanus Chimpanzee Modern Human Dentition

Morphology of face/Zygomatic Bone

Degree of Prognathism

Location of the foramen magnum

(at home) How does the location of the foramen magnum relate to bipedalism? Which of these two forms (modern human, chimpanzee) does A. africanus most resemble? Homework Questions:

An Ancestor to Call Our Own by: K Wong Name at least one ape-like and one human-like trait for Ardipithecus ramidus kadabba, Orrorin tugenensis, and Sahelanthropus tchadensis.

Was Sahelanthropus tchadensis bipedal? What evidence is there to back up the claim?

The Transforming Leap, From 4 Legs to 2 by: JN Wilford What are some of the reasons that have been proposed as explanations for the development of bipedalism. (Name at least 2)

According to this article, what does Owen Lovejoy propose may have been the motivating force for bipedalism? TERMS C/P3 shearing complex – the long, protruding upper canine of most hominoids sharpens itself against the lower third premolar when the animal closes its mouth (premolars 1 and 2 have been lost in catarrhines) dental arcade – the teeth row/shape of the palate (rectangular in apes, parabolic in humans) diastema – a space between teeth; absent in modern humans encephalization – refers to an increase in brain size over and beyond that explainable by an increase in body size holotype – a specimen of an organism that serves as the standard for a species or a subspecies; it is often the first of its kind to be scientifically reported and described

MYA – million years ago post-orbital constriction – refers to the degree of constriction behind the eye orbits prognathism – prominence of the snout; the opposite is orthognathism (a flat face; the condition in humans) sectorial premolar – first lower premolar of most hominoids in which there is a honing surface that sharpens the upper canine supraorbital tori – brow ridges

Y-5 molar cusp pattern – the arrangement of cusps on hominoid lower molars in which the 5 cusps form an inverted “Y”

SPECIMEN DESIGNATIONS Specimen designations usually consist of a combination of letters and numbers. The number portion of the designation usually varies from place to place, depending on the cataloging system utilized in naming specimens. However, the letter portion can help you greatly in remember geographic distribution (which may in turn assist you in associating some fossil specimens with others). Here are some of the more common designations you will see this semester.

OH stands for Olduvai hominid. These specimens were recovered at Olduvai Gorge which is in Tanzania in east Africa. This will help you differentiate east African specimens from south African specimens.

KNM-ER stands for Kenya National Museum – East Rudolph. These specimens were recovered on the east side of Lake Rudolph in Kenya (in east Africa) which is approximately 500 miles north of Olduvai Gorge. The northern-most shore of Lake Rudolph (now known as Lake Turkana) is in Ethiopia.

KNM-WT stands for Kenya National Museum – West Turkana. Lake Rudolf was renamed Lake Turkana in the late 1970s. These West Turkana exposures were mainly investigated after the name change and that is why the fossils have this designation.

AL stands for Afar Locality, which means these specimens were recovered in the Afar region of Ethiopia in east Africa.

LH stands for Laetoli hominid, which means these specimens were recovered in or near Laetoli, Tanzania in east Africa.

Sts stands for Sterkfontein, a cave in the Transvaal Valley region of South Africa.

SK stands for Swartkrans, another cave in the Transvaal Valley region of South Africa.