1. Internal carotid arterial canal size and scaling in Euarchonta: Re-assessing implications for arterial patency and phylogenetic relationships in early fossil primates.

    Journal of Human Evolution 97:123 (2016) PMID 27457550

    Primate species typically differ from other mammals in having bony canals that enclose the branches of the internal carotid artery (ICA) as they pass through the middle ear. The presence and relative size of these canals varies among major primate clades. As a result, differences in the anatomy ...
  2. Dust in the wind: How climate variables and volcanic dust affect rates of tooth wear in Central American howling monkeys.

    American Journal of Physical Anthropology 159(2):210 (2016) PMID 26426839

    Two factors have been considered important contributors to tooth wear: dietary abrasives in plant foods themselves and mineral particles adhering to ingested food. Each factor limits the functional life of teeth. Cross-population studies of wear rates in a single species living in different habi...
  3. Anthropology. New World monkey origins.

    Science 347(6226):1068 (2015) PMID 25745147

  4. The effect of differences in methodology among some recent applications of shearing quotients.

    American Journal of Physical Anthropology 156(1):166 (2015) PMID 25256698

    A shearing quotient (SQ) is a way of quantitatively representing the Phase I shearing edges on a molar tooth. Ordinary or phylogenetic least squares regression is fit to data on log molar length (independent variable) and log sum of measured shearing crests (dependent variable). The derived line...
  5. Dietary inference from upper and lower molar morphology in platyrrhine primates.

    PLoS ONE 10(3):e0118732 (2015) PMID 25738266 PMCID PMC4349698

    The correlation between diet and dental topography is of importance to paleontologists seeking to diagnose ecological adaptations in extinct taxa. Although the subject is well represented in the literature, few studies directly compare methods or evaluate dietary signals conveyed by both upper a...
  6. Biogeography in deep time - What do phylogenetics, geology, and paleoclimate tell us about early platyrrhine evolution?

    Molecular Phylogenetics and Evolution 82 Pt B:358 (2015) PMID 24333920

    Molecular data have converged on a consensus about the genus-level phylogeny of extant platyrrhine monkeys, but for most extinct taxa and certainly for those older than the Pleistocene we must rely upon morphological evidence from fossils. This raises the question as to how well anatomical data ...
  7. Oldest known cranium of a juvenile New World monkey (Early Miocene, Patagonia, Argentina): implications for the taxonomy and the molar eruption pattern of early platyrrhines.

    Journal of Human Evolution 74:67 (2014) PMID 25081638

    A juvenile cranium of Homunculus patagonicus Ameghino, 1891a from the late Early Miocene of Santa Cruz Province (Argentina) provides the first evidence of developing cranial anatomy for any fossil platyrrhine. The specimen preserves the rostral part of the cranium with deciduous and permanent al...
  8. Locomotor head movements and semicircular canal morphology in primates.

    PNAS 109(44):17914 (2012) PMID 23045679 PMCID PMC3497779

    Animal locomotion causes head rotations, which are detected by the semicircular canals of the inner ear. Morphologic features of the canals influence rotational sensitivity, and so it is hypothesized that locomotion and canal morphology are functionally related. Most prior research has compared ...
  9. Evidence for an Asian origin of stem anthropoids.

    PNAS 109(26):10132 (2012) PMID 22699505 PMCID PMC3387095

  10. Dietary quality and encephalization in platyrrhine primates.

    Proceedings of the Royal Society B: Biological ... 279(1729):715 (2012) PMID 21831898 PMCID PMC3248737

    The high energetic costs of building and maintaining large brains are thought to constrain encephalization. The 'expensive-tissue hypothesis' (ETH) proposes that primates (especially humans) overcame this constraint through reduction of another metabolically expensive tissue, the gastrointestina...
  11. Preliminary notes on a newly discovered skull of the extinct monkey Antillothrix from Hispaniola and the origin of the Greater Antillean monkeys.

    Journal of Human Evolution 60(1):124 (2011) PMID 21074827

  12. Auditory morphology and hearing sensitivity in fossil New World monkeys.

    Anatomical Record. Part A: Advances in Integrat... 293(10):1711 (2010) PMID 20730868

    In recent years it has become possible to investigate the hearing capabilities in fossils by analogy with studies in living taxa that correlate the bony morphology of the auditory system with hearing sensitivity. In this analysis, we used a jack-knife procedure to test the accuracy of one such s...
  13. New perspectives on anthropoid origins.

    PNAS 107(11):4797 (2010) PMID 20212104 PMCID PMC2841917

    Adaptive shifts associated with human origins are brought to light as we examine the human fossil record and study our own genome and that of our closest ape relatives. However, the more ancient roots of many human characteristics are revealed through the study of a broader array of living anthr...
  14. Technical note: Dental microwear textures of "Phase I" and "Phase II" facets.

    American Journal of Physical Anthropology 137(4):485 (2008) PMID 18785631

    The power stroke of mastication has been traditionally divided into two parts, one which precedes centric occlusion, and the other which follows it-"Phase I" and "Phase II," respectively. Recent studies of primate mastication have called into question the role of Phase II in food processing, as ...
  15. The oldest Asian record of Anthropoidea.

    PNAS 105(32):11093 (2008) PMID 18685095 PMCID PMC2516236

    Undisputed anthropoids appear in the fossil record of Africa and Asia by the middle Eocene, about 45 Ma. Here, we report the discovery of an early Eocene eosimiid anthropoid primate from India, named Anthrasimias, that extends the Asian fossil record of anthropoids by 9-10 million years. A phylo...
  16. The anatomy of Dolichocebus gaimanensis, a stem platyrrhine monkey from Argentina.

    Journal of Human Evolution 54(3):323 (2008) PMID 18001820

    Dolichocebus is known from the type skull encased in a concretion, numerous isolated teeth, parts of two mandibles, and a talus. The specimens come from the Trelew Member (early Miocene, Colhuehuapian South American Land Mammal Age) of the Sarmiento Formation near the village of Gaiman, Chubut P...
  17. New platyrrhine monkeys from the Solimões Formation (late Miocene, Acre State, Brazil).

    Journal of Human Evolution 50(6):673 (2006) PMID 16530809

    We report here a new fossil primate from the late Miocene of Brazil. The material consists of a lower first molar and a maxilla with P3-4. The fossils were collected in the Solimões Formation at the locality of Patos, upper Acre River, Acre State, Brazil. The locality is assigned to the Huayquer...
  18. Olfactory fossa of Tremacebus harringtoni (platyrrhini, early Miocene, Sacanana, Argentina): implications for activity pattern.

    The Anatomical Record Part A Discoveries in Mol... 281(1):1157 (2004) PMID 15481092

    CT imaging was undertaken on the skull of approximately 20-Myr-old Miocene Tremacebus harringtoni. Here we report our observations on the relative size of the olfactory fossa and its implications for the behavior of Tremacebus. The endocranial surface of Tremacebus is incomplete, making precise ...
  19. The paleobiology of Amphipithecidae, South Asian late Eocene primates.

    Journal of Human Evolution 46(1):3 (2004) PMID 14698683

    Analysis of the teeth, orbital, and gnathic regions of the skull, and fragmentary postcranial bones provides evidence for reconstructing a behavioral profile of Amphipithecidae: Pondaungia, Amphipithecus, Myanmarpithecus (late middle Eocene, Myanmar) and Siamopithecus (late Eocene, Thailand). At...
  20. Hypoglossal canal size in living hominoids and the evolution of human speech.

    Human Biology 75(4):473 (2003) PMID 14655872

    The relative size of the hypoglossal canal has been proposed as a useful diagnostic tool for the identification of human-like speech capabilities in the hominid fossil record. Relatively large hypoglossal canals (standardized to oral cavity size) were observed in humans and assumed to correspond...