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Recent paleontological collection in submerged caves in the eastern Dominican Republic has yielded new specimens of Antillothrix bernensis. Here we describe a complete cranium of an adult individual (MHD 20) and provide phenetic comparisons to other endemic Caribbean taxa and extant mainland platyrrhines using three-dimensional geometric morphometric methods (3DGM). Qualitative and quantitative comparisons support conclusions based on other recently described fossil material: Antillothrix has a dentition lacking clear dietary specialization, an elongated brain case with strong temporal lines, and a vertically oriented nuchal plane. MHD 20 shares a combination of traits with a previously published subadult specimen (MHD 01) including a deep depression at glabella, dorsoventrally elongated orbits, and a relatively large face. This shared morphology reinforces the taxonomic affinity of the two specimens, with differences between the two likely reflecting the younger ontogenetic age of MHD 01. Comparisons to the extant platyrrhines paint a complicated picture as the results of between-group principal components analyses (bgPCA) indicate that Antillothrix does not share a suite of morphological features exclusively with any one genus. Depending on which bgPC axes are visualized, and which subset of landmarks is included (i.e., only those describing the shape of the face/palate for inclusion of Xenothrix), MHD 20 is most similar in shape to the atelids, Alouatta, Lagothrix, and Brachyteles, or an otherwise "empty" region of shape space. It groups neither with Cebus nor Callicebus, two taxa that Antillothrix has been associated with in previous studies based on much less complete material. The Antillothrix cranium does not exhibit any of the derived characters classically used to diagnose or define any single clade; rather its morphology shares features with multiple platyrrhine groups. This is consistent with the interpretation that Antillothrix preserves a primitive morphology, which accords with the hypothesis positing an early arrival of platyrrhines in the Caribbean.

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Sixty male crania from three Platyrrhini and three Catarrhini genera were measured by means of the craniofunctional method. The aim was to analyze functional components of the skull and relate their function and the degree of encephalization to life history variables. We recognized two major and eight minor functional components. The objectives were to test (1) if within-taxa (Platyrrhini or Catarrhini) and/or between-taxa (Platyrrhini and Catarrhini) comparisons showed minor-component differentiation; and (2) if encephalization affects both primate groups differently. After standardization by size and scaling, 15 possible within-taxa and between-taxa comparisons were made. We found a strong phylogenetic signal, i.e., cranial differences were not randomly distributed, with the between-taxa variation being greater than within-taxa. Both hypotheses tested were accepted since: (1) There was no random variation between functional cranial components. They followed definite patterns for ancestral and derived traits. (2) Encephalization was present in all scaled comparisons, with Platyrrhini showing a higher degree of encephalization than Catarrhini. We conclude that major and minor craniofunctional components should be considered as correlated traits related to life history, because we found different patterns between platyrrhines and catarrhines, and within species of both taxa.

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En el mono Cebus apella, las glándulas salivales submandibulares se localizan en la área cervical, lateralmente a tráquea y están constituidas morfológicamente por cuatro tipos de células parenquimatosas que forman diferentes estructuras: 1. Acinos: que presentan células secretoras seromucosas, mucosas y mioepiteliales. Las células secretoras tienen retículo endoplásmico rugoso y complejo de Golgi desarrollados lo que permite a éstas una gran capacidad de síntesis, además presentan una acumulación considerable de gránulos de secreción. 2. Ductos intercalares: se caracterizan por tener células epiteliales cuboidales simples y células mioepiteliales. Los ductos conectan las células secretoras a los ductos granulosos y presentan escencialmente una función excretora. 3. Ductos estriados: consisten en células columnares altas con pliegues extensos en su membrana en las zonas basal y lateral. Presentan una cantidad pequeña de retículo endoplásmico rugoso y de gránulos, lo que sugiere una función de transporte de iones y agua. 4. Ductos excretores: constituidos por células columnares altas y forman la porción final de la vía excretora

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Metric features of the axon terminals and cell morphology of intrinsic projections of area 17 were studied in the Cebus apella. Anterograde and retrograde labeled cell appendages were obtained using saturated pellets and iontophoretic injections of biocytin in the operculum. Details of the histological and histochemical procedures have been described elsewhere (Amorim and Picanço-Diniz, 1996). We distinguished three labeled cell types: pyramidal, star pyramidal and stellate cells and three distinct morphologies of axon terminals were found: Ia, Ib and II, located at supragranular layers. Axon terminals of the group I innervate larger extent of striate cortex through longer intermediate segments, and acute branching angles compared to group II. Group II present on average similar characteristics of the smooth neurons axon terminals. The results taken together with the occurrence of only two types of synapses (I and II) from Gray's ultrastructural studies, seem to give an additional support to extend to the Cebus apella the major subdivision of neocortical neuronal morphology that classified them as smooth and spine neurons.

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The secretion of the subcommissural organ (SCO) is synthesized in the intrinsic cells of that structure, a neuroendocrine gland. The organelles involved in the synthesis of this secretion are rough-surfaced endoplasmic reticulum (RER) and the Golgi apparatus. It is still uncertain whether and to what extent the latter participates in the synthesis. In highly active secretory ependymal cells of the SCO, the Golgi apparatus exhibits distinct signs of intense activity. This suggests that the Golgi apparatus is involved in the preparation of the secretion, even if this is difficult to prove electron microscopically. The secretion is discharged from the optical part of the SCO-cells into the cerebrospinal fluid (CSF) of the IIIrd ventricle, where Reissner's fibre is formed. Different phases of release of the content of the secretory granula into the IIIrd ventricle are described; our findings are in agreement with previously published observations. In 2 cases delicately granulated and moderately electron-dense material was found in circumscriptly dilated vaults of the intercellular spaces. Release of secretory material into intercellular spaces appears to be possible, but is evidently infrequent. Regular occurrence of a basal (peripheral) discharge into the hypendymal capillaries is not unanimously agreed upon as yet. In this paper, a passage of granula is described from the cytoplasm of the end feet of SCO cells through the walls of the capillaries into the systemic circulation. This provides structural evidence that secretory material synthesized in the SCO is released into the capillaries. These observations must ultimately be confirmed with the aid of ultracytochemical methods, particularly using labelled material.

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Recognized species of sakis, South American monkeys of genus Pithecia (Cebidae), are P. hirsuta Spix, P. monachus E. Geoffroy, P. albicans Gray, P. pithecia Linnaeus. Evolutionary stages in sexual dichromatism in sakis and other primates are noted.

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In the present research, fibres and nerve endings of upper lip of the Cebus apella monkey have been studied. Upper lip of 8 Cebus apella were analysed. The pieces were prepared according to the technic of Castro's silver impregnation and submitted to serial sections 8 micra thick. Our results permit to conclude that the Cebus apella monkey's upper lip has a great number of free nerve endings, between connective and epithelial layers in the mucosa and in the skin. The aspects of nerve fibres and their free and organized endings, like Meissner's corpuscles, in the upper lip mucosa of the monkey, allow comparison of similarity with those of man. The nerve endings in the lip skin of the Cebus monkey are also abundant, characterizing the hair follicles and sebaceous glands innervation and the free nerve endings encountered in the connective tissue as well as in the sub-epithelial layer.

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Brazilian squirrel monkey kidneys removed before and after administration of parathormone were studied by microdissection, polarizing microscopy, alizarin red and von Kossa's stains, and microchemical analysis. Intralumenal crystalline-matrix masses were observed in both groups but were increased in frequency after parathormone administration. Specific staining showed the presence of calcium and phosphorus, and specific chemical tests suggested the presence of uric acid or urate salts. Refractile alizarin red positive droplets were observed in the tubular cells of the pars convoluta in parathormone-treated animals. Urinary stone formation in these animals is unique in that the location and types of stones produced are similar to that seen in man. The squirrel monkey is a good experimental model to study renal stone disease and further studies of its etiology, structure, composition, and means of control should be performed.

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Neurohistological observations of the tongues of the adult monkeys Cebus apella are described. It was noted that the Cebus tongue presents few vallate papilae situated mainly in the posterior and lateral parts; fungi and filiforms are spread all over the dorsal surface. Histologically there was evidence that numerous nerve fibres of variable size come from the deep layers of the tongue to the surface structure. In many regions they constitute plexuses, other cross the muscular and glandular layers, going to the epithelial layer of the tongue's mucosa. The vallate and fungiform papillae are supplied with abundant nerve fibres which terminate free and are furnished with many taste buds. The epithelium and surrounding connective tissue is innervated by the fibres with free or ramified endings. The muscular layer shows muscle fibres distributed in all directions and the presence of motor end plates and nerve fibres is evident.

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This paper presents information on the cranial and dental anomalies observed in the crania of three species of platyrrhine monkeys collected in Nicaragua. Cranial anomalies that are discussed include plagiocephaly, bregmatic fontanelle bones, Wormian bones, cranial trauma, and heterotopic bones. Among the dental anomalies that were studied were the following: crazing caries, periodontal and pulpal disorders, alveolar thinning, mechanical loss, excessive attrition, shear bite, impacted molars, supernumerary teeth, congenital agencies, congenital crown aberration, and irregular placement.

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The geographic pattern of coat color and craniometric variation were examined in Aotus. The coat color and pattern permitted recognition of the geographic origin of night monkeys from many parts of Latin America. The geographic pattern of craniometric variation differed from the pattern of phenotypic variation and led the authors to doubt the validity and usefulness of the currently recognized subspecific classification. Tooth eruption and bone ossification were studied in a sample of Aotus skeletons. Tentative criteria were presented for judging the ages of night monkeys by visual examination of their teeth or by x-ray of their teeth or bones.

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Electron microscopy of the absorption surface of the jejunal epithelium of the howler monkey Alouatta caraya showed the presence of core filaments implanted at the level of the terminal web in the microvilli. These microvilli are 5 to 7 mum long and up to 5 mum thick, their extraordinary development is attributed to a conditioned adaptation of the species to its feeding habits and nature of absorption.

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This is a preliminary study on the comparative microscopic anatomy of the external noses of platyrrhine monkeys. Platyrrhinism is caused by the lateral width of the internarium (Alar cartilages, soft tissue in the sulcus interalaris covered by the integument). The septum nasi, situated caudal to the internarium is not involved in platyrrhinism. Aotus and Alouatta are, according to the definition, truely playtrrhine. The division of the higher primates into Platyrrhina and Catarrhina is justified. The anterior surface of the internarium (sinus hairs) is a sensorial area.

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Chromosome analysis in 23 specimens of Alouatta s. seniculus trapped in different localities of Colombia were examined with the C- and Q-banding techniques. The chromosome numbers (2n=44) showed variations from 2n = 43 to 2n = 45 involving three and five microchromosomes, respectively. Two specimens also showed a structural chromosome variation involving a pericentric inversion of the chromosome No. 13. Chromosome measurements revealed an X chromosome with a value significantly smaller to that established for the standard mammalian X chromosome.

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