Question

Which of the following species are included among gracile australopithecines?
A. A. africanus
B. A. boisei
C. A. afarensis
D. A. anamensis
Choose the correct answer from the options given below:

• A. A, B and D only
• B. A, B and C only
• C. A, C and D only
• D. B, C and D only

Hint:

Remember the key distinction: "gracile" means slender or lightly built, while "robust" means strong and heavily built. The robust species ({P. boisei}, {P. robustus}, {P. aethiopicus}) are specialized for heavy chewing and are often grouped into their own genus, {Paranthropus}.

Answer 1

The Correct Option is C

Step 1: Australopithecine Classification:
Australopithecines are extinct hominins categorized into "gracile" and "robust" groups based on chewing-related features like teeth, jaws, and muscles.
- Gracile australopithecines are characterized by a lighter build, particularly in the skull and teeth, with less massive jaws and smaller molars.
- Robust australopithecines (often classified as Paranthropus) possess massive jaws, large molars, and prominent sagittal crests for large chewing muscle attachment.
Step 2: Species Classification:
Species classification examples:
- A. A. africanus: A classic example of a gracile australopithecine from South Africa.
- B. A. boisei: Also known as Paranthropus boisei, a "hyper-robust" australopithecine from East Africa, notable for its massive jaws and molars; not gracile.
- C. A. afarensis: An East African gracile australopithecine, famously represented by the "Lucy" fossil.
- D. A. anamensis: An early gracile australopithecine species.
Step 3: Conclusion:
Gracile australopithecine species include A. africanus, A. afarensis, and A. anamensis. A. boisei is a robust australopithecine. Therefore, the gracile species are A, C, and D.