Analysis of Primate Dental Microwear using Image Processing Techniques

This paper introduces Fourier transformation as a rapid, replicable means for characterizing and distinguishing patterns of microscopic wear on primate teeth. The two-dimensional power spectra obtained from numerical Fourier transformation are shown to be different between two test patterns, one of which is composed of linear features and the other of randomly-spaced dots. A comparison is made, using Fourier transformation, of dental microwear patterns of small samples of two primate species, Ateles geoffroyi, the spider monkey, and Chiropotes satanas, the bearded saki. Ateles, with a scratch-dominated pattern of microwear, has a Fourier transform resembling that of the linear test pattern. Chiropotes, with a pit-dominated microwear pattern, resembles the transform of the dot pattern. The significance of this is discussed in light of the dietary differences between the two species

Sobre los objetivos y resultados de la expedición paleontológica de Handel T. Martin (1903-04) a la Formación Santa Cruz en Patagonia austral

Between January and June 1904, Handel T. Martin (1862-1931), of the University of Kansas (KU), collected fossil vertebrates from the Early Miocene Santa Cruz Formation along the Río Gallegos and the Atlantic Coast of Patagonia, as his own private initiative. In his account of the expedition, Martin stated that when he and his companion, arrived in Buenos Aires, they visited Florentino Ameghino at the Museo Nacional. Martin’s album of photographs shows that he also visited the Museo de La Plata and Ameghino’s home in La Plata. Before heading to Patagonia, Martin assembled his equipment in Bahía Blanca, where his brother had settled. It is not clear if Martin collected a total of 235 or 395 specimens. Clearly, his main goal was to collect fossils to sell, as many specimens were later sold to different institutions in the United States and Europe by Martin himself and through Robert Ferris Damon, a well-known fossil and mineral trader of the time. To date, we have identified only about 170 specimens in formal collections. A large part of the collection – at least 130 of the choicest specimens – remained at KU, which constitutes one of the largest collections of Santacrucian vertebrates outside Argentina (in addition to the ones in the Yale Peabody Museum in New Haven, the Field Museum in Chicago, and the American Museum in New York). Although the collection at KU is largely neglected by paleontologists and has seldom been studied, it contains a good representation of the Santacrucian fauna, with many fine specimens.Entre enero y junio de 1904, Handel T. Martin (1862-1931), de la Universidad de Kansas (KU), colectó vertebrados fósiles de la Formación Santa Cruz (Mioceno temprano) a lo largo del Río Gallegos y la costa atlántica de Patagonia, como una iniciativa privada de Martin. En reporte de la expedición, Martin afirmó que cuando él y su compañero llegaron a Buenos Aires, visitaron a Florentino Ameghino en el (entonces) Museo Nacional. Su álbum de fotografías muestra que también visitó el Museo de La Plata y la casa de Ameghino en La Plata. Antes de dirigirse a la Patagonia, Martin organizó su equipo en Bahía Blanca, donde su hermano se había establecido. No hay certeza de si Martin recogió un total de 235 o 395 ejemplares. Claramente, su principal objetivo fue recoger fósiles para comercializar. Muchos especímenes fueron vendidos a instituciones en los Estados Unidos y Europa por Martin y Robert Ferris Damon, un comerciante de fósiles y minerales. Se han identificado cerca de 170 especímenes en colecciones formales. Gran parte de la colección -unos 130 de los mejores ejemplares- se mantuvo en KU, constituyendo una de las mayores colecciones de vertebrados santacrucenses fuera de Argentina (además de las del Museo Peabody de Yale en New Haven, el Museo Field de Chicago y el Museo Americano de Nueva York). Aunque la colección en KU es en gran medida ignorada por los paleontólogos y poco estudiada, contiene una buena representación de la fauna santacrucenses, con muchos ejemplares de calidad.Facultad de Ciencias Naturales y Muse

Technical note: dental microwear textures of Phase I and Phase II facets

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 they have found little muscle activity or accompanying bone strain following centric occlusion. That said, many researchers today look to Phase II facets to relate diet to patterns of dental microwear. This suggests the need to reevaluate microwear patterns on Phase I facets. Here we use texture analysis to compare and contrast microwear on facets representing both phases in three primate species with differing diets (Alouatta palliata, Cebus apella, and Lophocebus albigena). Results reaffirm that microwear patterns on Phase II facets better distinguish taxa with differing diets than do those on Phase I facets. Further, differences in microwear textures between facet types for a given taxon may themselves reflect diet. Some possible explanations for differences in microwear textures between facet types are proposed

The record of the typothere Pachyrukhos (Mammalia, Notoungulata) and the Chinchillid Prolagostomus (Mammalia, Rodentia) in the Santa Cruz Formation (early-middle Miocene) south to the Río Coyle, Patagonia, Argentina

The continental early–middle Miocene Santa Cruz Formation (SCF) from Patagonia is one of the most important stratigraphic units of southern South America in terms of the terrestrial Neogene record. Its fossil content was pivotal for establishing the succession of Cenozoic faunas from Patagonia and formed the basis of the Santacrucian South American Land Mammal Age. Despite the updated knowledge recently achieved, the stratigraphic distribution of many taxa within the SCF remains to be clarified. That is the case with the typothere notoungulate Pachyrukhos and the chinchillid rodent Prolagostomus. New information on the stratigraphy of the SCF along the north bank of the Río Gallegos and Cabo Buen Tiempo (Santa Cruz Province), together with a detailed analysis of the provenance information of the specimens in the principal old museum collections, sheds light on the record of these taxa south to Río Coyle. Our results show that the first recorded occurrence of both taxa in the area was between ~17 Ma and 17.41 Ma, restricted to the upper part of the SCF, including the upper part of the Estancia La Costa Member at Cañadón Las Totoras-Monte Tigre, and the superimposed Estancia La Angelina Member along the Río Gallegos and Cabo Buen Tiempo. Their presence suggests a trend to aridification in the upper part of the SCF south to the Río Coyle. These results are consistent with recent information obtained from other locations of the SCF north to the Río Coyle.La Formación Santa Cruz (FSC; Mioceno temprano–medio de Patagonia) es una de las unidades estratigráficas más importantes de América del Sur austral por su registro del Neógeno terrestre. Su contenido fósil fue fundamental para el establecimiento de la sucesión de faunas del Cenozoico de Patagonia y constituyó la base de la Edad Mamífero Santacrucense de América del Sur. A pesar de la reciente actualización de su conocimiento, la distribución estratigráfica de muchos taxones dentro de la FSC aún no se ha esclarecido. Tal es el caso del notoungulado tipoterio Pachyrukhos y del roedor chinchíllido Prolagostomus. Nueva información sobre la estratigrafía de la FSC en la margen norte del Río Gallegos y en Cabo Buen Tiempo y el análisis de la procedencia de ejemplares en colecciones de museos permitieron esclarecer el registro de esos taxones al sur del Río Coyle. Nuestros resultados indican que el primer registro de ambos taxones en el área sería entre ~17 Ma y 17,41 Ma, restringidos a la parte superior de la FSC, incluyendo la sección más alta del Miembro Estancia La Costa, en Cañadón Las Totoras-Monte Tigre, y el suprayacente Miembro Estancia La Angelina a lo largo del Río Gallegos y en Cabo Buen Tiempo. Su presencia sugiere una tendencia a la aridificación en la parte superior de la FSC al sur del Río Coyle. Estos resultados son consistentes con información reciente de otras localidades de la FSC al norte del Río Coyle.Fil: Vizcaíno, Sergio Fabián. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Bargo, María Susana. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Kay, Richard F.. University of Duke; Estados UnidosFil: Raigemborn, María Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentin

Tamaño de las raíces dentarias, brazos de palanca de la musculatura masticatoria y biología de homunculus patagonicus (primates) del mioceno temprano de Patagonia

Las inferencias sobre dieta de monos platirrinos miocenos se han basado en la morfología de los molares, específicamente las crestas. Aquí se estudia la superficie de las raíces de los dientes, área de anclaje del ligamento periodontal. Se utilizó una base de datos de imágenes Micro-CT de platirrinos actuales (calitriquinos, cebinos, pitécidos y atélidos), Tremacebus y Dolichocebus (Mioceno temprano) y Homunculus patagonicus (Mioceno temprano tardío). Basándose en las cicatrices musculares preservadas en los cráneos, se estimó el brazo de palanca de los músculos masticatorios en puntos de mordida desde el canino hasta el último molar. En los platirrinos actuales que se alimentan de exudados, las raíces de los caninos o premolares anteriores no son especialmente grandes; en los folívoros, las raíces de los molares son mucho más grandes que en los frugívoros de tamaño similar. Las raíces de los postcaninos de H. patagonicus son más grandes en relación a su tamaño corporal que en cualquier otro platirrino viviente analizado; las raíces postcaninas grandes, el excesivo desgaste de los dientes y las crestas cortantes moderadamente largas sugieren un consumo de alimentos abrasivos y resistentes. Sin embargo, la palanca aductora relativamente pobre de la mandíbula indica una desventaja mecánica para producir fuerzas de mordida elevadas en comparación con platirrinos actuales. Tremacebus y Dolichocebus también poseen superficies de las raíces más grandes que los platirrinos vivientes de tamaño equivalente y se asemejan a Homunculus por ser más prognatos y por el origen del músculo temporal ubicado posteriormente, rasgos que indican un sistema de palancas relativamente pobre.Until now, inferences about the diet of Miocene platyrrhine monkeys have relied upon the structure of the molar teeth, specifically the development of the crests on the molars. Here, using a library of Micro-CT images of a broad comparative sample of living platyrrhines (callitrichines, cebines, pitheciids and atelids), late early Miocene Homunculus, and the early Miocene taxa Tremacebus and Dolichocebus, we extend these inferences by examining the surface areas of the tooth roots, which serve as anchor points for the periodontal ligament.  We also estimate the leverage of the chewing muscles at bite points from the canine to the last molar, relying on muscle scars preserved on the skull. Extant platyrrhine gougers do not have especially large canine or anterior premolar roots.  The extant platyrrhine folivore, Alouatta fusca, has much larger molar roots than does the similar-sized frugivore Ateles geoffroyi.  Homunculus patagonicus, relative to body size, has larger postcanine roots than any extant platyrrhine in our sample. Homunculus also has poor masticatory leverage compared to the extant platyrrhines studied.  The large postcanine roots, heavy tooth wear, and moderately-long shearing crests suggests a diet of abrasive, resistant foods.  However, relatively poor jaw adductor leverage put the masticatory apparatus of Homunculus at a mechanical disadvantage for producing high bite forces, when compared to the condition in extant platyrrhines. Tremacebus or Dolichocebus, like Homunculus, have larger tooth root surfaces than comparable-sized living platyrrhines. The lack of adequate mandibular material makes observations about masticatory leverage in these taxa less precise but it seems clear that they also resemble Homunculus in having more prognathic faces and posteriorly located temporalis origins - all features of a relatively poor leverage system.Fil: Perry, Jonathan M. G.. Midwestern University; Estados UnidosFil: Kay, Richard F.. University of Duke; Estados UnidosFil: Vizcaíno, Sergio Fabián. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Bargo, María Susana. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentin

Climate stability across the Eocene-Oligocene transition, southern Argentina

Fossil mammal teeth from mid-latitude southern Argentina (∼46°S) that closely bracket the Eocene-Oligocene transition show no resolvable change in oxygen isotope compositions. In combination with paleofloral observations and geographic considerations, this finding implies not only that climate was essentially constant, despite interpretations elsewhere for major mid- and high-latitude cooling, but also that evolution of hypsodonty did not coincide with climate change during the Eocene-Oligocene transition. One possible explanation for Eocene-Oligocene transition climatic stability is that southern high-latitude cooling increased latitudinal temperature gradients and strengthened ocean circulation gyres, including the southward-flowing Brazil Current in the western South Atlantic. Regionally increased heat transport in the western Atlantic offset global cooling, producing a nearly constant temperature in southern South America. A more radical interpretation, supported by some marine data, is that the paradigm of major global cooling at the Eocene-Oligocene transition is largely false, in that mean sea-surface temperatures changed very little.Facultad de Ciencias Naturales y Muse

Fossil localities of the Santa Cruz Formation (Early Miocene, Patagonia, Argentina) prospected by Carlos Ameghino in 1887 revisited and the location of the Notohippidian

Between January and September of 1887 Carlos Ameghino carried out his first geologic and paleontological expedition to the Río Santa Cruz, Patagonia. Based on the fossils and geologic information compiled, in 1887 and 1889, Florentino Ameghino named more than 120 new species of extinct mammals and his Formación Santacruceña and Piso Santacruceño (Santacrucian stage). Data published by both brothers state that the specimens were collected in outcrops by the Río Santa Cruz, between 90 and 200 km west of its mouth. However, information in the posthumously published letters and Travel Diary of C. Ameghino allows us to recognize a fourth locality, Río Bote, at about 50 km further southwest. In 1900, 1902, F. Ameghino divided the Piso Santacruceño in a younger étage Santacruzienne and older étage Notohippidéen, restricting the geographical distribution of the latter to Kar Aiken locality, northeast of Lago Argentino. However, 15 of the 54 species that F. Ameghino listed as exclusively Notohippidian stage already had been named on specimens collected South to the Río Santa Cruz in 1887, two year prior to C. Ameghino's first visit to Kar Aiken. Based on historical information and several expeditions to the Río Santa Cruz and its environs, in this contribution we establish the geographical locations of the 1887 localities, formalize their names, evaluate the stratigraphic position of the fossil-bearing levels, and analyze the geographic extension of the Notohippidian, inferring that Río Bote is where C. Ameghino first collected species that came to define the Notohippidian.Facultad de Ciencias Naturales y Muse

Dissecting the functional behavior of the differentially phosphorylated prolyl isomerase, Pin1

Protein post‐translational modifications (PTMs) play an intricate role in a diverse range of cellular processes creating a complex PTM code that governs cell homeostasis. Understanding the molecular build‐up and the critical factors regulating this PTM code is essential for targeted therapeutic design whereby PTM mis‐regulation is prevalent. Here, we focus on Pin1, a peptidyl‐prolyl cis‐trans isomerase whose regulatory function is altered by a diverse range of PTMs. Through employing advanced mass spectrometry techniques in combination with fluorescence polarization and enzyme activity assays, we elucidate the impact of combinatorial phosphorylation on Pin1 function. Moreover, two phosphorylation sites were identified whereby Ser71 phosphorylation preceded Ser16 phosphorylation, leading to the deactivation of Pin1's prolyl isomerase activity before affecting substrate binding. Together, these findings shed light on the regulatory mechanisms underlying Pin1 function and emphasize the importance of understanding PTM landscapes in health and disease

On the objectives and results of the Handel T. Martin paleontological expedition (1903-04) to the Santa Cruz Formation in southern Patagonia

Entre enero y junio de 1904, Handel T. Martin (1862-1931), de la Universidad de Kansas (KU), colectó vertebrados fósiles de la Formación Santa Cruz (Mioceno temprano) a lo largo del Río Gallegos y la costa atlántica de Patagonia, como una iniciativa privada de Martin. En reporte de la expedición, Martin afirmó que cuando él y su compañero llegaron a Buenos Aires, visitaron a Florentino Ameghino en el (entonces) Museo Nacional. Su álbum de fotografías muestra que también visitó el Museo de La Plata y la casa de Ameghino en La Plata. Antes de dirigirse a la Patagonia, Martin organizó su equipo en Bahía Blanca, donde su hermano se había establecido. No hay certeza de si Martin recogió un total de 235 o 395 ejemplares. Claramente, su principal objetivo fue recoger fósiles para comercializar. Muchos especímenes fueron vendidos a instituciones en los Estados Unidos y Europa por Martin y Robert Ferris Damon, un comerciante de fósiles y minerales. Se han identificado cerca de 170 especímenes en colecciones formales. Gran parte de la colección - unos 130 de los mejores ejemplares - se mantuvo en KU, constituyendo una de las mayores colecciones de vertebrados santacrucenses fuera de Argentina (además de las del Museo Peabody de Yale en New Haven, el Museo Field de Chicago y el Museo Americano de Nueva York). Aunque la colección en KU es en gran medida ignorada por los paleontólogos y poco estudiada, contiene una buena representación de la fauna santacrucenses, con muchos ejemplares de calidad.Between January and June 1904, Handel T. Martin (1862-1931), University of Kansas (KU), collected fossil vertebrates from the Early Miocene Santa Cruz Formation along the Río Gallegos and the Atlantic Coast of Patagonia, as Martin’s private initiative. In the account of the expedition, Martin stated that when he and his companion, arrived in Buenos Aires, they visited Florentino Ameghino at the Museo Nacional. His album of photographs shows that he also visited the Museo de La Plata and Ameghino’s home in La Plata. Before heading to Patagonia, Martin assembled his equipment in Bahía Blanca, where his brother had settled. It is not clear if Martin collected a total of 235 or 395 specimens. Clearly, his main goal was to collect fossils to sell, as many specimens were later sold to different institutions in the United States and Europe by Martin by himself and through Robert Ferris Damon, a well-known fossil and mineral trader of the time. To date, we have identified only about 170 specimens in formal collections. A large part of the collection – at least 130 of the choicest specimens – remained at KU, which constitutes one of the largest collections of santacrucian vertebrates outside Argentina (in addition to the ones in the Yale Peabody Museum in New Haven, the Field Museum in Chicago, and the American Museum in New York). Although the collection at KU is largely neglected by paleontologists and has seldom been studied, it contains a good representation of the Santacrucian fauna, with many fine specimens

The in vitro loss of penicillamine in plasma, albumin solutions, and whole blood: Implications for pharmacokinetic studies of penicillamine

The recent development of a high performance liquid chromatography assay method for the analysis of penicillamine in biological samples such as plasma, whole blood, and urine has provided a specific and sensitive assay method to aid in the study of penicillamine pharmacokinetics. Several investigators have reported measuring the plasma concentration of penicillamine. Some of these investigators have indicated that the plasma must be assayed immediately. However, such restrictions can limit the feasibility of a pharmacokinetic study. The results of this paper demonstrate the instability of penicillamine in plasma, albumin solutions, and whole blood. The rate of loss of penicillamine was shown to be influenced by the concentration of albumin. As a result of the significant loss of penicillamine over a short period of time, plasma or whole blood samples must be deproteinated immediately upon collection to avoid the loss of reduced penicillamine. Methods are presented for the preparation of biological samples so that the oxidation of penicillamine is prevented and the samples can be held for several days prior to analysis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23196/1/0000123.pd