The 'Palaeogene strata' of the Itaboraí Basin (upper Paleocene-lower Eocene), Southeastern Brazil, has preserved 29 genera and almost 50 species of metatherians (about 65% of its mammalian diversity). Among them, Eobrasilia coutoi Simpson, 1947 is the most enigmatic due to its quite fragmentary nature. We redescribe this species by assigning new molars, first micro-CT and microwear data, and reinterpreting its systematic affinities. Eobrasilia coutoi weighed about 5.92 kg, thus representing the largest Palaeogene non-sparassodont metatherian from South America and Antarctica. A phylogenetic analysis recovered Eobrasilia and Periprotodidelphis as sister taxa (Eobrasiliidae rank nov.) within Polydolopimorphia. Lower molars morphofunctional variables (talonid relative area and height, and width by the length of the lower molar) suggest that E. coutoi has a pattern more similar to that of extant New World Primates (Cebidae, Pitheciidae) than extant didelphids. Buccolingually oriented wear facets on the parastyle and postmetacrista suggest a developed ectental masticatory component. Its microwear pattern is characterized by a predominance of fine scratches and small pits, resembling the pattern of callitrichids and cebids but differing from these in having longer scratches. Eobrasilia coutoi was likely a sclerocarpophagous metatherian, being able to exploit unripe fruits and seeds as food; however, it cannot be considered a specialized durophagous/hard-object feeder like extant pitheciines. The results suggest a Tropical humid 'mammalian trophic biome' for the localities in the Itaboraí Basin with Eobrasilia coutoi. This is consistent with an early Eocene age (likely contemporaneous to the Early Eocene Climatic Optimum) inferred for Itaboraí youngest faunal assemblage.

Primates adopt a variety of hand postures during an impressive diversity of locomotor and manipulative behaviors. Morphological research has found that elements of the hand skeleton, such as the hamate, hold key information for inferring hand use and locomotor kinematics in extinct species. However, debate remains surrounding how and when specialized locomotor hand postures evolved. This debate persists due to uncertainty concerning which taxa possess derived character states for given traits and whether those states evolved via selective response to functional demands or are the result of other biological processes, such as developmental constraint or phylogeny. Phylogenetic comparative methods provide one way to disentangle the role of phylogeny in shaping skeletal morphology and thus can provide clarity concerning which traits arose via other means, such as directed selection. Here, we quantify several functionally relevant hamate traits and employ phylogenetic methods (bayou, OUwie) to infer if and how selection has shaped these traits in particular taxa or clades. We find that selection caused the hamulus to reduce in tarsiers and to lengthen in cebids and hominoids, potentially related to increased demand for grip capability during behaviors like tool use or-in hominoids-below-branch suspension. Evidence from traits associated with suspension suggests that this behavior evolved independently in hylobatids and hominids. Shifts toward shorter hamate body lengths in Gorilla and hominins cannot be explained by phylogeny alone. Variability among hominines eschews simple interpretation, but this result suggests that if knuckle-walking evolved once in hominines, then the hamate subsequently lengthened in Pan.

Goeldi's monkey (Callimico goeldii, the lone species in this genus) shows an array of characteristics that are typical for both New World primate families, the Cebidae and the Callitrichidae, and as such their taxonomic classification has remained in question. Based on DNA, the genus Callimico is regarded as a member of the monophyletic group of clawed New World monkeys (Callitrichidae). Callitrichids, as a rule, give birth to twins, which are blood chimeras due to placental blood vessel anastomoses. In contrast, wild and captive Callimico almost exclusively have singleton births, as in all cebids. To address whether Callimico shares chimeric twinning with other callitrichids, we did DNA profiling of the only presently available twin pair of captive Callimico. DNA banding patterns revealed distinct differences between the twins, indicating an absence of blood chimerism. We infer that predominantly single birth in Callimico most likely represents a derived state that evolved independently in this genus, rather than the ancestral callitrichid condition.

Vitamin C is a normal component of human milk and is a key milk antioxidant. The recommended vitamin C intake in lactating women is 120 mg daily, and for infants aged 6 months or less is 40 mg daily.[1] High daily doses up to 1000 mg increase milk levels, but not enough to cause a health concern for the breastfed infant and is not a reason to discontinue breastfeeding. Nursing mothers may need to supplement their diet to achieve the recommended intake or to correct a known deficiency. Maternal doses of vitamin C in prenatal vitamins at or near the recommended intake do not alter milk levels. Donor milk subjected to Holder pasteurization (62.5 degrees C for 30 minutes) has lower vitamin C levels than levels reported in fresh milk and lower than unpasteurized milk.[2-4] Holder pasteurization does not reduce biochemical signals of donor milk lipid oxidation status.[3] However, the relative antioxidant contribution of donor milk vitamin C content compared to vitamin E after pasteurization has not been studied. The flash-heat method of treating breastmilk to reduce HIV transmission (placing a container of expressed milk in a water bath and brining the water to a rolling boil) does not change the milk vitamin C content.[5] Freezing (-20 degrees C) freshly expressed mature milk from hospitalized mothers of term and preterm infants does not change milk vitamin C levels for at least 3 months of freezer storage.[6] After 6 to 12 months of freezing (-20 degrees C), vitamin C levels can decrease by 15 to 30%. Storage at -80 degrees C preserves vitamin C levels for up to 8 months, with 15% loss by 12 months.[7]

There have been multiple published phylogenetic analyses of platyrrhine primates (New World monkeys) using both morphological and molecular data, but relatively few that have integrated both types of data into a total evidence approach. Here, we present phylogenetic analyses of recent and fossil platyrrhines, based on a total evidence data set of 418 morphological characters and 10.2 kilobases of DNA sequence data from 17 nuclear genes taken from previous studies, using undated and tip-dating approaches in a Bayesian framework. We compare the results of these analyses with molecular scaffold analyses using maximum parsimony and Bayesian approaches, and we use a formal information theoretic approach to identify unstable taxa. After a posteriori pruning of unstable taxa, the undated and tip-dating topologies appear congruent with recent molecular analyses and support largely similar relationships, with strong support for Stirtonia as a stem alouattine, Neosaimiri as a stem saimirine, Cebupithecia as a stem pitheciine, and Lagonimico as a stem callitrichid. Both analyses find three Greater Antillean subfossil platyrrhines (Xenothrix, Antillothrix, and Paralouatta) to form a clade that is related to Callicebus, congruent with a single dispersal event by the ancestor of this clade to the Greater Antilles. They also suggest that the fossil Proteropithecia may not be closely related to pitheciines, and that all known platyrrhines older than the Middle Miocene are stem taxa. Notably, the undated analysis found the Early Miocene Panamacebus (currently recognized as the oldest known cebid) to be unstable, and the tip-dating analysis placed it outside crown Platyrrhini. Our tip-dating analysis supports a late Oligocene or earliest Miocene (20.8-27.0 Ma) age for crown Platyrrhini, congruent with recent molecular clock analyses.

The platyrrhine family Cebidae (capuchin and squirrel monkeys) exhibit among the largest primate encephalization quotients. Each cebid lineage is also characterized by notable lineage-specific traits, with capuchins showing striking similarities to Hominidae such as high sensorimotor intelligence with tool use, advanced cognitive abilities, and behavioral flexibility. Here, we take a comparative genomics approach, performing genome-wide tests for positive selection across five cebid branches, to gain insight into major periods of cebid adaptive evolution. We uncover candidate targets of selection across cebid evolutionary history that may underlie the emergence of lineage-specific traits. Our analyses highlight shifting and sustained selective pressures on genes related to brain development, longevity, reproduction, and morphology, including evidence for cumulative and diversifying neurobiological adaptations across cebid evolution. In addition to generating a high-quality reference genome assembly for robust capuchins, our results lend to a better understanding of the adaptive diversification of this distinctive primate clade.

The major histocompatibility complex (MHC) is an important gene complex contributing to adaptive immunity. Studies of platyrrhine MHC have focused on identifying experimental models of immune system function in the equivalent Human Leukocyte Antigen (HLA). These genes have thus been explored primarily in captive platyrrhine individuals from research colonies. However, investigations of standing MHC variation and evolution in wild populations are essential to understanding its role in immunity, sociality and ecology. Capuchins are a promising model group exhibiting the greatest habitat diversity, widest diet breadth and arguably the most social complexity among platyrrhines, together likely resulting in varied immunological challenges. We use high-throughput sequencing to characterize polymorphism in four Class II DR and DQ exons for the first time in seven capuchin species. We find evidence for at least three copies for DQ genes and at least five for DRB, with possible additional unrecovered diversity. Our data also reveal common genotypes that are inherited across our most widely sampled population, Cebus imitator in Sector Santa Rosa, Costa Rica. Notably, phylogenetic analyses reveal that platyrrhine DQA sequences form a monophyletic group to the exclusion of all Catarrhini sequences examined. This result is inconsistent with the trans-species hypothesis for MHC evolution across infraorders in Primates and provides further evidence for the independent origin of current MHC genetic diversity in Platyrrhini. Identical allele sharing across cebid species, and more rarely genera, however, does underscore the complexity of MHC gene evolution and the need for more comprehensive assessments of allelic diversity and genome structure.

Multiple behavioral and biomechanical analyses have demonstrated that capuchin monkeys (Cebus and Sapajus) are specialized for breaking down hard-object foods as compared to other cebid monkeys. In addition to a complex suite of craniodental adaptations, it has specifically been demonstrated that capuchins possess highly complex dental enamel, with extensive Hunter-Schreger banding and other decussation, that likely serve as an adaptation to resist crack propagation during hard-object feeding. Furthermore, it has been demonstrated that robust capuchins (Sapajus spp., formerly Cebus apella) demonstrate further adaptation for hard-object feeding than other capuchins, routinely breaking down extremely mechanically challenging foods. However, there has been no comparison of dental enamel complexity in robust versus gracile capuchins, to assess whether the dental enamel in Sapajus follows this same pattern of further specialization. Therefore, this study compares dental enamel complexity in images of dental thin sections from a sample of robust versus gracile capuchins using image compression ratio (ICR) analysis. ICR is a variable that correlates with enamel complexity, such that higher ICR values are indicative of increased complexity in the form of enamel decussation. We found no significant difference between robust and gracile capuchins when assessing all teeth in our sample together, however, we did find that robust capuchins have significantly higher ICR values than gracile capuchins for canine teeth, specifically. Our results support prior studies suggesting that robust capuchins are specialized to generate increased masticatory loads with their anterior dentition, specifically, as compared to gracile species.

The phylogenetic position of owl monkeys, grouped in the genus Aotus, has been a controversial issue for understanding Neotropical primate evolution. Explanations of the difficult phylogenetic assignment of owl monkeys have been elusive, frequently relying on insufficient data (stochastic error) or scenarios of rapid speciation (adaptive radiation) events. Using a coalescent-based approach, we explored the population-level mechanisms likely explaining these topological discrepancies. We examined the topological variance of 2,192 orthologous genes shared between representatives of the three major Cebidae lineages and the outgroup. By employing a methodological framework that allows for reticulated tree topologies, our analysis explicitly tested for non-dichotomous evolutionary processes impacting the finding of the position of owl monkeys in the cebid phylogeny. Our findings indicated that Aotus is a sister lineage of the callitrichines. Most gene trees (>50%) failed to recover the species tree topology, although the distribution of gene trees mismatching the true species topology followed the standard expectation of the multispecies coalescent without reticulation. We showed that the large effective population size of the common ancestor of Aotus and callitrichines was the most likely factor responsible for generating phylogenetic uncertainty. On the other hand, fast speciation scenarios or introgression played minor roles. We propose that the difficult phylogenetic placement of Aotus is explained by population-level processes associated with the large ancestral effective size. These results shed light on the biogeography of the early cebid diversification in the Miocene, highlighting the relevance of evaluating phylogenetic relationships employing population-aware approaches.

Dipetalonema caudispina (Molin, 1858) and D. gracile (Rudolphi, 1809) (Filarioidea: Onchocercidae) are two of six known species of filarial nematodes that parasitize Neotropical non-human primates. Adult filariae were collected from the thoracic and abdominal cavities of 38 of 44 specimens of Sapajus macrocephalus (Spix, 1823) and nine of ten specimens of Cebus albifrons (Humboldt, 1812) (Primates: Cebidae), distributed in the Yavarí-Mirín river basin and used locally for human consumption. Co-occurrence of D. caudispina and D. gracile is reported for the first time, with a prevalence of 18.5% (10 of 54 hosts examined). Our finding of D. caudispina and D. gracile in cebids from the Peruvian Amazon constitutes a new geographical record for both filariae, two new host records for D. caudispina, and the first report of D. gracile in S. macrocephalus. In addition, we provide morphometric data for D. caudispina, complementing the original description, as well as scanning electron microscopy details on the structure of the area rugosa and number of caudal papillae in males.

Serum samples were collected from 24 platyrrhines of seven diurnal species housed with outdoor access at Bristol Zoo Gardens (United Kingdom) to test 25-hydroxyvitamin D3 (25OHD3) levels as part of the veterinary department's preventative health care program. Samples were collected in August 2008 (summer) and January 2009 (winter) to examine the effect of season on 25OHD3 levels. Dietary levels of vitamin D3 remained the same throughout the study period and fell within the range of 2000-4000 IU/kg dry matter, in accordance with current primate guidelines. Statistical analysis showed that there was no significant difference between the platyrrhines' summer 25OHD3 values (range, <4.0->150.0 μg/L) and winter 25OHD3 values (range, <4.0-80.1 μg/L). However, ultraviolet B (UVB) measurements taken at the zoo during the study period confirmed that UVB levels were significantly higher in summer (mean reading for 1200-1300 hours GMT time period, 153.8 μW/cm2) compared with winter (mean reading for 1200-1300 hours GMT time period, 19.4 μW/cm2). The 25OHD3 levels measured were generally found to be low compared with previously published values from healthy captive and wild platyrrhines.

Undoubted fossil Cebidae have so far been primarily documented from the late middle Miocene of Colombia, the late Miocene of Brazilian Amazonia, the early Miocene of Peruvian Amazonia, and very recently from the earliest Miocene of Panama. The evolutionary history of cebids is far from being well-documented, with notably a complete blank in the record of callitrichine stem lineages until and after the late middle Miocene (Laventan SALMA). Further documenting their evolutionary history is therefore of primary importance.