How Old Is Luzia? Luminescence Dating and Stratigraphic Integrity at Lapa Vermelha, Lagoa Santa, Brazil

During an excavation in the 1970s, a disarticulated female human skeleton, later nicknamed Luzia, was discovered at 12m depth at Lapa Vermelha rockshelter in central Brazil. Radiocarbon dating of associated charcoal suggested an age of 11.4-16.4 ka for the skeleton. The scattering of the skeletal parts, some uncertainty about the exact provenience of the skeleton, and evidence of pervasive insect turbation in the archaeological layers have raised doubts about the accuracy of the age. Luminescence dates for the depositional ages of the sediments at Lapa Vermelha are reported here. Single-grain optically stimulated luminescence (OSL) of quartz along with grain-size, chemical and micro-morphological analyses of the sediments were employed to assess stratigraphic integrity, particularly the degree of sediment mixing. These various lines of evidence point to high stratigraphic integrity with little mixing at Lapa Vermelha. Sediments closest to where Luzia was recovered give OSL ages ranging from 12.7 to 16.0 ka, thus not refuting the original dates. (C) 2010 Wiley Periodicals, Inc.

Lapa das boleiras rockshelter: stratigraphy and formation processes at a paleoamerican site in Central Brazil

Lapa clas Boleiras rockshelter, a Paleoamerican archaeological site in Central Brazil, was intensely occupied by humans from 10,000 C-14 BP (11.8 cal kyr BP), until approximately 7500 C-14 BP (8.4 cal kyr BP). In this paper we present some interpretations about the formation processes operating on the site. One of our main conclusions is that the bulk of accumulated sediments at the site is of anthropogenic origin: they are constituted by volumetrically significant quantities of plant ash remains, what is somewhat unexpectedly in view of prevailing models about the lifestyle of Paleoamerican hunter-gatherers in South America. The evidence we discuss below is also consistent with paleoenvironmental data that suggest a dry period during the mid-Holocene in the region, probably leading to a decrease in human occupation [Araujo, A.G.M., Neves, W., Pilo, L.B., Atui, J.P., 2005. Holocene dryness and human Occupation in Brazil during the `Archaic Gap`. Quaternary Research 64, 298-307]. We surmise that both factors underpin a surprising reduction in sediment accumulation at the site during the mid-Holocene. (C) 2008 Published by Elsevier Ltd.

The legs: a key to bird evolutionary success

Birds are the most diverse and largest group of extant tetrapods. They show marked variability, yet much of this variation is superficial and due to feather and bill color and shape. Under the feathers, the skeleto-muscular system is rather constant throughout the bird group. The adaptation to flight is the explanation for this uniformity. The more obvious morphological adaptations for flight are the wings, but the trunk is always rigid, the tail is short and the neck is flexible, since all these features are correlated with flying behaviour. Unrelated to the exigencies of flight, the legs always have three long bones, and all the birds walk on their toes. This leg structure is a striking plesiomorphic feature that was already present in related dinosaurs. The multi-purpose potential of the legs is the result of the skeletal architecture of a body with three segmented flexed legs. This configuration provides mechanical properties that allow the use of the legs as propulsive, paddling, foraging or grooming tools. It is the association of diverse modes of locomotion-walking, running, hopping, flying and swimming-that have enabled the birds to colonize almost all the environments on Earth.

Rock Art at the Pleistocene/Holocene Boundary in Eastern South America

Background: Most investigations regarding the First Americans have primarily focused on four themes: when the New World was settled by humans; where they came from; how many migrations or colonization pulses from elsewhere were involved in the process; and what kinds of subsistence patterns and material culture they developed during the first millennia of colonization. Little is known, however, about the symbolic world of the first humans who settled the New World, because artistic manifestations either as rock-art, ornaments, and portable art objects dated to the Pleistocene/Holocene transition are exceedingly rare in the Americas. Methodology/Principal Findings: Here we report a pecked anthropomorphic figure engraved in the bedrock of Lapa do Santo, an archaeological site located in Central Brazil. The horizontal projection of the radiocarbon ages obtained at the north profile suggests a minimum age of 9,370640 BP, (cal BP 10,700 to 10,500) for the petroglyph that is further supported by optically stimulated luminescence (OSL) dates from sediment in the same stratigraphic unit, located between two ages from 11.7 +/- 0.8 ka BP to 9.9 +/- 0.7 ka BP. Conclusions: These data allow us to suggest that the anthropomorphic figure is the oldest reliably dated figurative petroglyph ever found in the New World, indicating that cultural variability during the Pleistocene/Holocene boundary in South America was not restricted to stone tools and subsistence, but also encompassed the symbolic dimension.

GAUDY JUVENILE PLUMAGES OF CINEREOUS MOURNER (LANIOCERA HYPOPYRRA) AND BRAZILIAN LANIISOMA (LANIISOMA ELEGANS)

We describe the juvenile plumages of the Cinereous Mourner (Laniocera hypopyrra) and the Brazilian Laniisoma (Laniisoma elegans). Both L. hypopyrra and L. elegans possess a dramatically conspicuous plumage as juveniles in contrast to the generally cryptic plumage pattern exhibited by most juvenile birds. They are predominantly covered by cinnamon-orange feathers with black terminal spots, contrasting with the nest and the predominant colors of their environment. This colorful plumage presumably makes them more at risk from predation by visually oriented animals (e.g., raptors and primates), during one of the most vulnerable phases of their life, and strongly suggests these plumages function as a true, or false (mimicry), signal of 'unprofitability'. Previous knowledge concerning the phylogenetic relationships between these two genera, and the juvenile plumage patterns of other species placed in the Tityridae indicate this shared character in L. hypopyrra and L. elegans represents a synapomorphy within this clade, thereby providing additional evidence of their relationship. Received 13 December 2011. Accepted 1 May 2012.

O mundo coberto de penas Família e utopia em Vidas secas

O texto analisa a trama dos sonhos, dos desejos e da realidade de uma família de retirantes nordestinos que, tratados como bichos, sonham um dia fazer valer sua condição de homens. Embora atravessada pela dúvida e pela incerteza impostas pelos obstáculos de uma realidade desumana, a narrativa fala também da persistência de sonhos e desejos que não deixa morrer a esperança utópica dos personagens e do próprio autor, ainda que vaga, do advento de um mundo humanizado.