Do gracile australopithecines have a sagittal crest?

In brief, gracile forms refer to the species of the genus Australopithecus, excluding Paranthropus. Therefore, the main characteristic facial features of these species include smaller cheek teeth, pronounced prognathism, and less flared cheeks. Also, they had no sagittal crest. However, they had a sagittal crest.

Is Australopithecus boisei gracile or robust?

Australopithecus afarensis and africanus, and the other species above, are known as gracile australopithecines, because of their relatively lighter build, especially in the skull and teeth. (Gracile means “slender”, and in paleoanthropology is used as an antonym to “robust”.)

When referring to gracile australopithecines gracile refers to what?

The gracile australopithecines (members of the genus Australopithecus) (Latin australis “of the south”, Greek pithekos “ape”) are a group of extinct hominids that are closely related to humans.

What are the physical characteristics of robust australopithecines?

They are characterized by several features of the skull that give them a “robust” appearance when compared to other, more gracile hominins. The most notable of these features are large, thickly enameled, postcanine teeth that were supported by deep and broad mandibular corpora with tall and broad rami (Fig. 1).

Does brain size increase much in the australopithecines through time?

Homo sapiens brain size increases over time within the sapiens super-species clade (figure 2 and table 1).

Was the first robust australopithecine found?

Australopithecus robustus and A. boisei are also referred to as “robust” australopiths. Robert Broom recovered the first specimen of a robust australopith in 1938 from the South African cave site of Kromdraai.

What is the most energetically expensive uses the most calories organ in the human body?

The brain – Our most energy-consuming organ.

What is a gracile jaw?

In the case of australopiths, “gracile” and “robust” refer to the relative size of the jaws, teeth and chewing muscles (all contributing to the “masticatory apparatus”). Traditionally, graciles include the ≥2 million year old Australopithecus afarensis and africanus, and robusts include the later A.

What are robust australopithecines also called?

boisei are also referred to as “robust” australopiths. In addition to a well-developed skull crest for the attachment of the temporalis (or temporal muscle, which is used in chewing), other specializations for strong chewing include huge cheek teeth, massive jaws, and powerfully built cheekbones that project forward.

Are humans gracile or robust?

The postcranial skeleton of modern Homo sapiens is relatively gracile compared with other hominoids and earlier hominins. This gracility predisposes contemporary humans to osteoporosis and increased fracture risk.

What is the difference between a robust and a gracile Australopithecus?

In the case of australopiths, “gracile” and “robust” refer to the relative size of the jaws, teeth and chewing muscles (all contributing to the “masticatory apparatus”). Traditionally, graciles include the ≥2 million year old Australopithecus afarensis and africanus, and robusts include the later A.

What makes a robust skull different from gracile Skull?

The robust forms had larger teeth and a stouter skull structure than gracile types. In general, the features that distinguish the robust skull are associated with a strong chewing apparatus — larger teeth, a heavier jaw, and a sagittal crest allowing a large attachment surface for the jaw muscles.

What are the facial features of a gracile?

Therefore, the main characteristic facial features of these species include smaller cheek teeth, pronounced prognathism, and less flared cheeks. Also, they had no sagittal crest. On that account, gracile species were frugivores that had a fruit-based diet.

What are the names of the robust australopithecines?

In general, Paranthropus is another term for the robust Australopithecines. In this, there are three significant species that represent the robust form. They are A. robustus (2.5 Mya), A. boisei ( 2.5-1.4 Mya), and A. aethiopicus (2.5 Mya).