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L Rook

Publications and source records attributed to L Rook.

9 recordsLinked to original sources

Last Glacial mammals in South America: a new scenario from the Tarija Basin (Bolivia).

The chronology, sedimentary history, and paleoecology of the Tarija Basin (Bolivia), one of the richest Pleistocene mammalian sites in South America, are revised here based on a multidisciplinary study, including stratigraphy, sedimentology, geomorphology, paleontology, isotope geochemistry, and (14)C geochronology. Previous studies have indicated a Middle Pleistocene age for this classic locality. We have been able to obtain a series of (14)C dates encompassing all the fossil-bearing sequences previously studied in the Tarija Basin. The dated layers range in age from about 44,000 to 21,000 radiocarbon years before present (BP), indicating that the Tarija fauna is much younger than previously thought. Glacial advances correlated to marine isotopic stages (MIS) 4 and 2 (ca. 62 and 20 ka BP, respectively) are also documented at the base and at the very top of the Tarija-Padcaya succession, respectively, indicating that the Bolivian Altiplano was not dry but sustained an ice cap during the Last Glacial Maximum. The results of this multidisciplinary study enable us to redefine the chronological limits of the Tarija sequence and of its faunal assemblage and to shift this paleontological, paleoclimatological, and paleoecological framework to the time interval from MIS 4 to MIS 2.

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Fossil Macaca remains from RDB quarry (Villafranca d'Asti, Italy): new data and overview.

Mentioned in faunal lists since the late 1960s, Macaca remains from Villafranca d'Asti (early Villafranchian, Italy) were never described in detail. If some doubts were reported in the past about the related stratigraphic position, at present, partly thanks to the original acquisition labels, there is enough information to place these finds within the updated stratigraphic and biochronologic framework of the Villafranca d'Asti area. The reported sample consists of upper dentition and postcranial bones. By size and morphology all these remains are clearly Cercopithecinae, comparable with the extant Macaca sylvanus and mostly distinguishable from Mesopithecus, Dolichopithecus and Paradolichopithecus. The dental remains in particular give us the opportunity to discuss an inferred European size trend from smallest Pliocene macaques up to the larger living species M. sylvanus. Although Pliocene localities in western Europe have yielded so far only scanty Macaca finds, our data (even if preliminary) refute a major overall size difference between the extant Barbary macaque and the related fossil remains.

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Oreopithecus was a bipedal ape after all: evidence from the iliac cancellous architecture.

Textural properties and functional morphology of the hip bone cancellous network of Oreopithecus bambolii, a 9- to 7-million-year-old Late Miocene hominoid from Italy, provide insights into the postural and locomotor behavior of this fossil ape. Digital image processing of calibrated hip bone radiographs reveals the occurrence of trabecular features, which, in humans and fossil hominids, are related to vertical support of the body weight, i.e., to bipedality.

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Evidence of hominid-like precision grip capability in the hand of the Miocene ape Oreopithecus.

Functional and allometric analyses of the hand of the late Miocene ape Oreopithecus bambolii (Tuscany, Italy) reveal a series of features that reflect an improved grasping capability including firm pad-to-pad precision gripping that apes are unable to perform. Related features such as hand length, relative thumb length, a deep and large insertion area for the tendon of the long thumb flexor, and the form of the metacarpal 2/capitate articulation are not present in extant or fossil apes. In these features, the Oreopithecus hand closely matches the pattern of early hominids, presumably as a response to similar functional demands.

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Late turolian Mesopithecus (mammalia, primates, Colobinae) from Italy.

This paper reports on new finds and re-discovered old collections of the latest Miocene colobine Mesopithecus from Italian localities. New finds are reported from the Baccinello V3 faunal assemblage and from the Monticino gypsum quarry (Brisighella) and newly rediscovered teeth from the Casino basin are herein described. The latter two samples are attributed to the species Mesopithecus pentelicus, while the allocation of the Baccinello V3 sample is unclear and for the moment is attributed to Mesopithecus sp. indet. A fourth Italian locality that yielded Mesopithecus remains is Gravitelli. Unfortunately the latter specimens are lost, and from the literature it is impossible to furnish an accurate specific attribution. The taxonomic allocation of latest Miocene Mesopithecus species is briefly discussed.

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A one-million-year-old Homo cranium from the Danakil (Afar) Depression of Eritrea.

One of the most contentious topics in the study of human evolution is that of the time, place and mode of origin of Homo sapiens. The discovery in the Northern Danakil (Afar) Depression, Eritrea, of a well-preserved Homo cranium with a mixture of characters typical of H. erectus and H. sapiens contributes significantly to this debate. The cranium was found in a succession of fluvio-deltaic and lacustrine deposits and is associated with a rich mammalian fauna of early to early-middle Pleistocene age. A magnetostratigraphic survey indicates two reversed and two normal magnetozones. The layer in which the cranium was found is near the top of the lower normal magnetozone, which is identified as the Jaramillo subchron. Consequently, the human remains can be dated at approximately 1 million years before present.

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