Laetoli toes andAustralopithecus afarensis

Tuttle, Russell H.; Webb, David; Baksh, Michael

doi:10.1007/bf02438142

Cited by 35 publications

(19 citation statements)

References 20 publications

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“…Finally, the Laetoli footprints demonstrate that at 3.5 million years ago, a hominin species had evolved a longitudinal arch (White, 1980;White and Suwa, 1987). Unless A. afarensis did not make the Laetoli footprints as argued by some (Tuttle et al, 1991;Harcourt-Smith and Hilton, 2005), these footprints are evidence that A. afarensis had an arched foot. Such an arched foot would have limited midfoot mobility (Kidd, 1993).…”

Section: Evolution Of the Stable Midfootmentioning

confidence: 86%

Revisiting the “midtarsal break”

DeSilva

2009

American J Phys Anthropol

159

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The midtarsal break was first described in this journal nearly 75 years ago to explain the ability of non-human primates to lift their heel independently of the rest of the foot. Since the initial description of the midtarsal break, the calcaneocuboid joint has been assumed to be the anatomical source of this motion. Recently, however, it has been suggested that the midtarsal break may occur at the cuboid-metatarsal joint, rather than at the calcaneocuboid joint. Data compiled from X-rays, dissections, manual manipulation of living primate feet, video of captive catarrhines, and osteological specimens concur that the midtarsal break is a complex motion caused by dorsiflexion at both joints with the cuboid-metatarsal joint contributing roughly 2/3 of total midfoot dorsiflexion, and the calcaneocuboid joint only about 1/3 of total midfoot dorsiflexion. The convexity of the proximal articular surface of the fourth and fifth metatarsals and corresponding concave cuboid facets provide skeletal correlates for the presence of midfoot dorsiflexion at the cuboid-metatarsal joint. Study of hominin metatarsals from Australopithecus afarensis, A. africanus, Homo erectus, and the metatarsals and a cuboid from the OH 8 foot show little capacity for dorsiflexion at the cuboid-metatarsal joint. These results suggest that hominins may have already evolved a stable midfoot region well adapted for the push-off phase of bipedalism by at least 3.2 million years ago. These data illuminate the evolution of the longitudinal arch and show further evidence of constraints on the arboreal capacity in early hominins.

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Section: Evolution Of the Stable Midfootmentioning

confidence: 86%

Revisiting the “midtarsal break”

DeSilva

2009

American J Phys Anthropol

159

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“…333 collection includes an abundant and diverse array of postcrania (Bush et al, 1982;Latimer et al, 1982;Lovejoy et al, 1982a,b,c), though it is difficult to assign isolated elements to particular individuals from this locality (e.g., Behrensmeyer et al, 2003). The Laetoli hominin footprints add further information on the bipedal locomotion of A. afarensis (e.g., White, 1980a;Charteris et al, 1981;Leakey, 1987;Tuttle, 1987;White and Suwa, 1987;Tuttle et al, 1991;Raichlen et al, 2008).…”

Section: The Postcranium Of Australopithecus Afarensismentioning

confidence: 99%

“…This is an interesting observation given that a medial longitudinal arch is present in the Laetoli footprints. Tuttle et al (1987Tuttle et al ( , 1991Tuttle, 1981) argued that the Hadar pedal phalanges were too long and curved to create the more humanlike Laetoli trail. In the views of Tuttle et al (1991) and Harcourt- Smith and Aiello (2004), the geologically younger Hadar fossils evince a more primitive pedal morphology than is expressed in the older Laetoli footprint trail.…”

Section: The Postcranium Of Australopithecus Afarensismentioning

confidence: 99%

“Lucy” redux: A review of research on Australopithecus afarensis

Kimbel

Delezene

2009

American J Phys Anthropol

208

140

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In the 1970s, mid-Pliocene hominin fossils were found at the sites of Hadar in Ethiopia and Laetoli in Tanzania. These samples constituted the first substantial evidence for hominins older than 3.0 Ma and were notable for some remarkable discoveries, such as the ''Lucy'' partial skeleton and the abundant remains from the A.L. 333 locality at Hadar and the hominin footprint trail at Laetoli. The Hadar and Laetoli fossils were ultimately assigned to the novel hominin species Australopithecus afarensis, which at the time was the most plesiomorphic and geologically ancient hominin taxon. The discovery and naming of A. afarensis coincided with important developments in theory and methodology in paleoanthropology; in addition, important fossil and genetic discoveries were changing expectations about hominin divergence dates from extant African apes. This coincidence of events ensured that A. afarensis figured prominently in the last 30 years of paleoanthropological research. Here, the 301 year history of discovery, analysis, and interpretation of A. afarensis and its contexts are summarized and synthesized. Research on A. afarensis continues and subject areas in which further investigation is needed to resolve ongoing debates regarding the paleobiol- Just over three decades ago, the east African early hominin species Australopithecus afarensis was recognized as the oldest, most apelike human ancestor. Although specimens now attributed to the species had resided in fossil collections since the 1930s, the bulk of the sample was amassed during field work in the 1970s at two sites, Hadar, Ethiopia, and Laetoli, Tanzania. Today, the species' hypodigm numbers more than 400 specimens collected from a half-dozen sites, most of which are still actively being worked (Table 1). Refinements in radioisotopic dating have established the species' first and last known appearances at 3.7 and 3.0 Ma, respectively. At the time of their discovery, these specimens constituted the first informative sample of hominin fossils older than 3.0 Ma.Studies on subjects ranging from the rise of striding bipedal locomotion to the origin of the uniquely human pattern of growth and development to the evolution of hominin dietary adaptations have drawn heavily on data from the remains of A. afarensis. Taxonomic and phylogenetic research, which experienced a major renaissance in paleoanthropology beginning around the time when A. afarensis was discovered, has benefited from the extensive baseline data on fossil hominin skeletal and dental variation residing in the Hadar site-sample. Some of the research topics that focus on A. afarensis-the extent to which terrestrial bipedality was the committed form of locomotion, the degree of sexual dimorphism in body size and implications for social behavior, and the ''shape'' of the phylogenetic tree prior to the emergence of the Homo and robust australopith lineages, to name just three prominent examples-are still actively debated today, which merely drives home the message that finding solutions to scien...

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“…afarensis had already made a large anatomical committment to bipedality, greater than that of any living ape (Stern and Susman, 1983;Latimer et al, 1987;Lovejoy, 1989,1990;Gebo, 1992a). Ifthe Laetoli footprints belong to A. afarensis (Tuttle, 1985(Tuttle, , 1990Tuttle et al, 1991b) and if our interpretation concerning the hallux of A. afarensis (Latimer and Lovejoy, 1990) are correct, it is clear that A. afarensis did not possess a grasping big toe (Lovejoy, 1978;Day and Wickens, 1980;Stern and Susman, 1983;White and Suwa, 1987;Latimer and Lovejoy, 1990;McHenry, 1991;Gebo, 1992a). Without a grasping big toe, it is hard to conceive of a hominid lower limb being well adapted for arboreality, moderately long and curved toes or not.…”

Section: What Are the Advantages Of Arm Suspension For Living Primates?mentioning

confidence: 99%

Climbing, brachiation, and terrestrial quadrupedalism: Historical precursors of hominid bipedalism

Gebo

1996

Am. J. Phys. Anthropol.

212

214

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The vertical-climbing account of the evolution of locomotor behavior and morphology in hominid ancestry is reexamined in light of recent behavioral, anatomical, and paleontological findings and a more firmly established phylogeny for the living apes. The behavioral record shows that African apes, when arboreal, are good vertical climbers, and that locomotion during traveling best separates the living apes into brachiators (gibbons), scrambling/ climbing/brachiators (orangutans), and terrestrial quadrupeds (gorillas and chimpanzees). The paleontological record documents frequent climbing as an ancestral catarrhine ability, while a reassessment of the morphology of the torso and forelimb in living apes and Atelini suggests that their shared unique morphological pattern is best explained by brachiation and forelimb suspensory positional behavior. Further, evidence from the hand and foot points to a terrestrial quadrupedal phase in hominoid evolution prior to the adoption of bipedalism. The evolution of positional behavior from early hominoids to hominids appears to have begun with an arboreal quadrupedal-climbing phase and proceeded though an orthograde, brachiating, forelimb-suspensory phase, which was in turn followed by arboreal and terrestrial quadrupedal phases prior to the advent of hominid bipedality. The thesis that protohominids climbed down from the trees to become terrestrial bipeds needs to be reexamined in light of a potentially long history of terrestriality in the ancestral protohominid.

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Laetoli toes andAustralopithecus afarensis

Cited by 35 publications

References 20 publications

Revisiting the “midtarsal break”

Revisiting the “midtarsal break”

“Lucy” redux: A review of research on Australopithecus afarensis

Climbing, brachiation, and terrestrial quadrupedalism: Historical precursors of hominid bipedalism

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