Australopithecus africanus

Author(s):  
Brian Villmoare
2019 ◽  
Vol 5 (8) ◽  
pp. eaax3250 ◽  
Author(s):  
Théo Tacail ◽  
Jeremy E. Martin ◽  
Florent Arnaud-Godet ◽  
J. Francis Thackeray ◽  
Thure E. Cerling ◽  
...  

Nursing is pivotal in the social and biological evolution of hominins, but to date, early-life behavior among hominin lineages is a matter of debate. The calcium isotopic compositions (δ44/42Ca) of tooth enamel can provide dietary information on this period. Here, we measure the δ44/42Ca values in spatially located microsized regions in tooth enamel of 37 South African hominins to reconstruct early-life dietary-specific variability in Australopithecus africanus, Paranthropus robustus, and early Homo. Very low δ44/42Ca values (<−1.4‰), indicative of milk consumption, are measured in early Homo but not in A. africanus and P. robustus. In these latter taxa, transitional or adult nonmilk foods must have been provided in substantial quantities relative to breast milk rapidly after birth. The results suggest that early Homo have continued a predominantly breast milk–based nursing period for longer than A. africanus and P. robustus and have consequently more prolonged interbirth interval.


2010 ◽  
Vol 139 (1) ◽  
pp. 149-156 ◽  
Author(s):  
R. D'ANASTASIO ◽  
T. STANISCIA ◽  
M. L. MILIA ◽  
L. MANZOLI ◽  
L. CAPASSO

SUMMARYBrucellosis is a worldwide disease. Although it has been eradicated in some countries, it continues to be an important disease in many farming areas. Previous works have described the evolution and diffusion of brucellosis in antiquity through direct analysis of ancient human remains collected by the University Museum of Chieti, Italy, and by using paleopathological and historical data. The earliest published case was reported in a skeletal individual dated to the Middle Bronze Age. However, our research group has diagnosed vertebral brucellosis in the partial skeleton of the late Pliocene Australopithecus africanus, demonstrating that this infectious disease occasionally affected our direct ancestors 2·3–2·5 million years ago. The frequency of brucellosis increased during the Roman period, when the disease would almost certainly have been endemic in Roman society, and during the Middle Ages. Most paleopathological cases involve adult male skeletal individuals, and lumbar vertebrae and sacroiliac joints are most commonly involved.


2017 ◽  
Author(s):  
Ian Towle ◽  
Joel D. Irish ◽  
Marina Elliott ◽  
Isabelle De Groote

AbstractTooth root grooves and other ante-mortem dental tissue loss not associated with caries found on or near the cementoenamel junction (CEJ) are commonly termed non-carious cervical lesions. Three main processes are implicated in forming these lesions: abrasion, dental erosion, and abfraction. As yet, these lesions have not been described in non-Homo hominins. In this study South African fossil hominin collections were examined for evidence of any type of non-carious cervical lesion. Only one individual shows ante-mortem root grooves consistent with non-carious cervical lesions. Two teeth, a mandibular right permanent lateral incisor (STW 270) and canine (STW 213), belonging to the same Australopithecus africanus individual, show clear ante-mortem grooves on the labial root surface. These lesions start below the CEJ, extend over a third of the way toward the apex, and taper to a point towards the lingual side. Microscopic examination revealed no clear directional striations. The shape of these grooves is extremely similar to clinical examples of dental erosion, with the lack of striations supporting this diagnosis. These are the oldest hominin examples of non-carious cervical lesions and first described in a genus other than Homo; further, the lesions suggest that this individual regularly consumed or processed acidic food items.


Author(s):  
Adam D. Gordon ◽  
David J. Green ◽  
William L. Jungers ◽  
Brian G. Richmond

Major changes in body shape occurred during human evolution, but questions remain about body shape in australopiths. The present study investigates the specifics of the presumed relationships between limb indices and positional behavior underlying prior work that compared proportions among extant hominids in order to make inferences about extinct hominins. We find that although both intermembral index or ratio of diaphyseal and articular proportions distinguish humans from great apes, neigher correlates well with variation in the degree of arboreality in the locomotor repertoire of extant hominids. Brachial index and a ratio of diaphyseal and articular dimensions from the fore- and hindlimb, however, do correlate with degree of arboreality, and scale slightly positively allometrically within species in all extant taxa. These two observations are taken into consideration in a more nuanced interpretation of a reanalysis of articular-diaphyseal limb proportions in an expanded sample of the Sterkfontein postcrania. This study confirms previous findings that Australopithecus africanus had larger forelimb dimensions in relation to hindlimb dimensions than modern humans and A. afarensis, similar to the patterns seen in extant apes, particularly western gorillas. However, data presented here suggest that interpreting a particular taxon as “human-like” or “ape-like” may be overly simplistic. Instead, while both A. africanus and A. afarensis were almost certainly committed bipeds that incorporated some arboreality into their locomotor repertoire, A. africanus apparently used a set of locomotor behaviors that was more distinct from that of A. afarensis than Pan troglodytes and Gorilla gorilla are from each other.


Author(s):  
Tracy L. Kivell ◽  
Kelly R. Ostrofsky ◽  
Brian G. Richmond ◽  
Michelle S.M. Drapeau

This chapter presents description and analysis of the metacarpals and manual phalanges from Sterkfontein. Although the morphology is generally similar across the sample where there are duplicates of the same element, there are differences in size that are quite remarkable within the context of all South African hominins. Some very large specimens suggest the presence of individuals at Sterkfontein with much larger hands, and presumably larger body size, at Sterkfontein than those of A. sediba MH2, H. naledi and the Swartkrans hominins. Australopithecus africanus had human-like proportions, but this may be plesiomorphic within the hominoid clade. The potentially less mobile trapezium-Mc1 joint, absence of a fully developed palmar pulp on the distal thumb, more limited pronation of the index finger, and potentially more wedge-shaped trapezoid inferred from the preserved external morphology, is consistent with lower manipulative loading of the thumb than is typical of later Homo. As for other forelimb elements, moderately curved manual phalanges suggests a greater reliance on forelimb-dominated locomotor behaviors and perhaps selection for more frequent use of an arboreal environment in A. africanus than is found in A. afarensis. Thus, within this broader context, the Sterkfontein fossil hominin remains are not unusual. The Sterkfontein hand fossils suggest an overall manipulative and locomotor loading regime that was more similar to that of other South African australopiths and distinct from that of later Homo, but more refined functional interpretations require additional fossil evidence, particularly from associated hand skeletons


Author(s):  
M Melchionna ◽  
A Mondanaro ◽  
C Serio ◽  
S Castiglione ◽  
M Di Febbraro ◽  
...  

Abstract A distinctive trait in primate evolution is the expansion in brain mass. The potential drivers of this trend and how and whether encephalization influenced diversification dynamics in this group are hotly debated. We assembled a phylogeny accounting for 317 primate species, including both extant and extinct taxa, to identify macroevolutionary trends in brain mass evolution. Our findings show that Primates as a whole follow a macroevolutionary trend for an increase in body mass, relative brain mass and speciation rate over time. Although the trend for increased encephalization (brain mass) applies to all Primates, hominins stand out for their distinctly higher rates. Within hominins, this unique trend applies linearly over time and starts with Australopithecus africanus. The increases in both speciation rate and encephalization begin in the Oligocene, suggesting the two variables are causally associated. The substitution of early, stem Primates belonging to plesiadapiforms with crown Primates seems to be responsible for these macroevolutionary trends. However, our findings also suggest that cognitive capacities favoured speciation in hominins.


2020 ◽  
Vol 117 (15) ◽  
pp. 8416-8423 ◽  
Author(s):  
Leoni Georgiou ◽  
Christopher J. Dunmore ◽  
Ameline Bardo ◽  
Laura T. Buck ◽  
Jean-Jacques Hublin ◽  
...  

Bipedalism is a defining trait of the hominin lineage, associated with a transition from a more arboreal to a more terrestrial environment. While there is debate about when modern human-like bipedalism first appeared in hominins, all known South African hominins show morphological adaptations to bipedalism, suggesting that this was their predominant mode of locomotion. Here we present evidence that hominins preserved in the Sterkfontein Caves practiced two different locomotor repertoires. The trabecular structure of a proximal femur (StW 522) attributed to Australopithecus africanus exhibits a modern human-like bipedal locomotor pattern, while that of a geologically younger specimen (StW 311) attributed to either Homo sp. or Paranthropus robustus exhibits a pattern more similar to nonhuman apes, potentially suggesting regular bouts of both climbing and terrestrial bipedalism. Our results demonstrate distinct morphological differences, linked to behavioral differences between Australopithecus and later hominins in South Africa and contribute to the increasing evidence of locomotor diversity within the hominin clade.


2003 ◽  
Vol 44 (5) ◽  
pp. 581-597 ◽  
Author(s):  
Nikolaas J. van der Merwe ◽  
J.Francis Thackeray ◽  
Julia A. Lee-Thorp ◽  
Julie Luyt

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