• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 568
  • 72
  • 68
  • 28
  • 24
  • 22
  • 13
  • 11
  • 11
  • 11
  • 11
  • 11
  • 11
  • 6
  • 6
  • Tagged with
  • 996
  • 223
  • 118
  • 100
  • 87
  • 72
  • 65
  • 64
  • 63
  • 61
  • 52
  • 51
  • 49
  • 48
  • 43
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

North American archaic ochotonids Hesperolagomys and Russellagus (Mammalia: Lagomorpha) and geometric constraints on the evolution of hypsodonty in lagomorphs

Bair, Andrea R. January 1900 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2006. / Title from title screen (site viewed on Oct. 19, 2006). PDF text: vii, 264 p. : ill., maps ; 4.73Mb. UMI publication number: AAT 3209966. Includes bibliographical references. Also available in microfilm, microfiche and paper formats.
42

The comparative paleoecology of late Miocene Eurasian hominoids

Scott, Robert Smith. Kappelman, John W. January 2004 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: John Kappelman. Vita. Includes bibliographical references. Also available from UMI.
43

Shape and size variability in lower second molars of extant hominoids and extinct hominin species with particular reference to modern homo sapiens and its potential for use as an analogue species in the context of fossil hominin dental variability comparisons

Dykes, Susan Jane January 2018 (has links)
Thesis is submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Faculty of Science, School of Geosciences, University of the Witwatersrand, Johannesburg, 2018 / Teeth make up the bulk of hominin fossil material and are useful in taxonomic assessments. In this thesis, discriminant function, principal components and randomised CV analyses on large samples of lower second molars (n=778) from five extant reference species, both sexually dimorphic and non-dimorphic, provide estimates of ranges of size-shape variability to be expected within a single species. However, there is evidence that diet-driven tooth-size reduction and cusp simplification has expanded the ranges of shape and size variability of Homo sapiens in some populations, in areas exposed to soft, undemanding diets since the transition to agriculture and increased use of cooking, food processing and ceramics from about 12500 years ago. Molar size and shape changes are less evident in communities retaining a hunter-gatherer subsistence strategy, requiring strong dentognathic structures with robust teeth to masticate harder, tougher foodstuffs. These factors, driving divergent variability in tooth size and shape, are unique to modern humans. Using a novel mathematically-based landmarking methodology, developed to allow the inclusion of severely worn teeth, intra-species size-shape variability was assessed from 63 lower M2s representing nine African Plio-Pleistocene species. The first hypotheses tested in this thesis address the question of which extant hominoid species might be suitable for use as analogue species for comparisons with fossil hominin molars, and whether uniquely modern-human anomalous size-shape variability exhibited by lower second molars might disqualify modern Homo sapiens for such analyses. Secondly, where lower second molar size-versus-shape variability ratios measured for fossil species do not match those of either a sexually dimorphic or a non-dimorphic extant species, evaluations are made as to whether samples attributed to single hominin species might actually represent specimens from more than one species present in the relevant assemblages, whether sexual dimorphism may have been greater in fossil species than in extant species, and whether some individual specimens attributed to any fossil species might be misclassified. Results of the analyses indicate that uniquely human subsistence strategy divergences are identifiable in the size-shape variability of lower second molars. Furthermore, specimens representing Australopithecus afarensis, Australopithecus africanus and Paranthropus robustus in this study exhibit very high variability and may indicate the presence of more than one species in their respective assemblages. / EM2018
44

The genus category and cranial morphometrics of the Catarrhini with implications for fossil hominins

Coate, Jack Andrew, Medical Sciences, Faculty of Medicine, UNSW January 2007 (has links)
Recently, the number of hominin genera has increased dramatically. Prior to the announcement of Ardipithecus, only two genera were used by paleoanthropologists: Australopithecus and Homo. Presently, up to eight hominin genera are used: Sahelanthropus, Orrorin, Ardipithecus, Australopithecus, Praeanthropus, Kenyanthropus, Paranthropus and Homo. Unlike species concepts, the genus category has not received wide critical examination. To investigate the use of the genus category in paleoanthropology, a comparative framework drawing on morphometric data from a large number of catarrhines is developed. Cranial variables include 36 standard linear measurements from representatives of catarrhine genera across the major tribes/families. This study seeks to assess whether too few or too many hominin genera have been recognized compared with extant catarrhines. Moreover, two published hypotheses about the use of Homo are examined: 1) Wood & Collard's (1999) proposal to transfer Homo habilis/rudolfensis to Australopithecus; and 2) Goodman et al's (1998) classification of both humans and chimpanzees in Homo. To analyze these cranial variables and a number of shape indices calculated from them, as well as to assess competing hypotheses, univariate, bivariate and multivariate statistical approaches are used. The results allow the identification of a set of variables and shape indices which distinguish genera across the catarrhines. Importantly, body size seems to be the major separator of catarrhine genera, reinforcing the idea that they occupy discrete adaptive zones. Moreover, differences between these genera mostly represent contrasts in the size of the neuroversus the viscerocranium. When applied to hominins, a picture emerges which distinguishes them from extant catarrhines: cranial shape rather than size is the major component distinguishing them; this suggests that extinct hominins occupied similar habitats and adaptive zones; variability in size and shape within hominin genera is much lower than extant catarrhines; and the major differences seen in shape among hominins are the result of encephalization in Homo. It is concluded here that both Wood & Collard's (1999) and Goodman et al.'s (1998) proposals appear to be premature. Moreover, while the earliest hominins may be too finely split at the genus level, the evidence for distinction of Australopithecus and Paranthropus is solid.
45

The genus category and cranial morphometrics of the Catarrhini with implications for fossil hominins

Coate, Jack Andrew, Medical Sciences, Faculty of Medicine, UNSW January 2007 (has links)
Recently, the number of hominin genera has increased dramatically. Prior to the announcement of Ardipithecus, only two genera were used by paleoanthropologists: Australopithecus and Homo. Presently, up to eight hominin genera are used: Sahelanthropus, Orrorin, Ardipithecus, Australopithecus, Praeanthropus, Kenyanthropus, Paranthropus and Homo. Unlike species concepts, the genus category has not received wide critical examination. To investigate the use of the genus category in paleoanthropology, a comparative framework drawing on morphometric data from a large number of catarrhines is developed. Cranial variables include 36 standard linear measurements from representatives of catarrhine genera across the major tribes/families. This study seeks to assess whether too few or too many hominin genera have been recognized compared with extant catarrhines. Moreover, two published hypotheses about the use of Homo are examined: 1) Wood & Collard's (1999) proposal to transfer Homo habilis/rudolfensis to Australopithecus; and 2) Goodman et al's (1998) classification of both humans and chimpanzees in Homo. To analyze these cranial variables and a number of shape indices calculated from them, as well as to assess competing hypotheses, univariate, bivariate and multivariate statistical approaches are used. The results allow the identification of a set of variables and shape indices which distinguish genera across the catarrhines. Importantly, body size seems to be the major separator of catarrhine genera, reinforcing the idea that they occupy discrete adaptive zones. Moreover, differences between these genera mostly represent contrasts in the size of the neuroversus the viscerocranium. When applied to hominins, a picture emerges which distinguishes them from extant catarrhines: cranial shape rather than size is the major component distinguishing them; this suggests that extinct hominins occupied similar habitats and adaptive zones; variability in size and shape within hominin genera is much lower than extant catarrhines; and the major differences seen in shape among hominins are the result of encephalization in Homo. It is concluded here that both Wood & Collard's (1999) and Goodman et al.'s (1998) proposals appear to be premature. Moreover, while the earliest hominins may be too finely split at the genus level, the evidence for distinction of Australopithecus and Paranthropus is solid.
46

Stratigraphic distribution of Southern Australian tertiary marsupiate echinoids with special reference to the St. Vincent Basin /

Kinsman, J. E. Unknown Date (has links) (PDF)
Thesis (B.Sc.(Hons.))--University of Adelaide, Dept. of Geology and Mineralogy, 1973?
47

Paleobiogeography of Miocene to Pliocene Equinae of North America a phylogenetic biogeographic and niche modeling approach /

Maguire, Kaitlin Clare. January 2008 (has links)
Thesis (M.S.)--Ohio University, June, 2008. / Title from PDF t.p. Includes bibliographical references.
48

Dynamique des paléoenvironnements à huîtres du Crétacé Supérieur nord-aquitain (SO France) et du Mio-Pliocène andalou (SE Espagne) : biodiversité, analyse séquentielle, biogéochimie /

Videt, Blaise. January 2004 (has links)
Thesis (doctoral)--Université de Rennes I, 2003. / Includes bibliographical references (p. 249-261). Also available on the Internet.
49

Laetoli Pliocene paleoecology : a reanalysis via morphological and behavioral approaches /

Musiba, Charles M. January 1999 (has links)
Thesis (Ph. D.)--University of Chicago, Dept. of Anthropology, December 1999. / Includes bibliographical references. Also available on the Internet.
50

The influence of differential production and dissolution on the stable isotope composition of planktonic foraminifera /

Erez, Jonathan. January 1978 (has links)
Thesis (Ph. D.)--M.I.T., Dept. of Earth and Planetary Sciences, 1979. / Supervised by S. Honjo. Bibliography: p. 110-119.

Page generated in 0.0347 seconds