Effect of rutin and chloroquine on White Leghorn chickens infected with Plasmodium (Bennettinia) juxtanucleare.

Plasmodium juxtanucleare is one of the agents that cause avian malaria in chickens and little is known about the treatment of the infection. The aim of this study was to compare the antimalarial activities of rutin and chloroquine in chickens infected with P. juxtanucleare after immunosuppression with corticosteroid. Antimalarial activity was verified in 33 fowls by evaluation of parasitemia levels in Giemsa-stained blood smears taken to 30 days. Rutin did not exert a reduction in parasitemia from P. juxtanucleare when compared to chloroquine treatment that kept the parasites at a low level, demonstrating its antimalarial effect. During the course of the infection, the trophozoite stage predominated (80%), followed by schizont (17%) and gametocyte (3%). Maximum parasitemia levels were recorded on day 12 in control and rutin groups. There were no significant differences in the hematocrit values, weight body or the temperature of the fowls among the groups evaluated (p > 0.05).

Middle Eocene primate tarsals from China: implications for haplorhine evolution.

We describe tarsal remains of primates recovered from the Middle Eocene (approximately 45 mya) Shanghuang fissures in southern Jiangsu Province, China. These tarsals document the existence of four higher-level taxa of haplorhine primates and at least two adapid species. The meager and poorly preserved adapid material exhibits some similarities to European adapines like Adapis. The haplorhine primates are divided into two major groups: a "prosimian group" consisting of Tarsiidae and an unnamed group that is anatomically similar to Omomyidae; and an "anthropoid group" consisting of Eosimiidae and an unnamed group of protoanthropoids. The anthropoid tarsals are morphologically transitional between omomyids (or primitive haplorhines) and extant telanthropoids, providing the first postcranial evidence for primates which bridge the prosimian-anthropoid gap. All of the haplorhines are extremely small (most are between 50-100 g), and the deposits contain the smallest euprimates ever documented. The uniqueness of this fauna is further highlighted by the fact that no modern primate community contains as many tiny primates as does the fauna from Shanghuang.

The oldest known anthropoid postcranial fossils and the early evolution of higher primates.

The middle Eocene primate family Eosimiidae, which is known from sites in central and eastern China and Myanmar, is central to efforts to reconstruct the origin and early evolution of anthropoid or 'higher' primates (monkeys, apes and humans). Previous knowledge of eosimiid anatomy has been restricted to the dentition and an isolated petrosal bone, and this limited anatomical information has led to conflicting interpretations of early anthropoid phylogeny. Here we describe foot bones of Eosimias from the same middle Eocene sites in China that yield abundant dental remains of this primate. Tarsals of Eosimias show derived anatomical traits that are otherwise restricted to living and fossil anthropoids. These new fossils substantiate the anthropoid status of Eosimias and clarify the phylogenetic position of anthropoids with respect to other major primate clades. Early anthropoids possessed a mosaic of primitive and derived traits in their postcranial skeletons, reflecting their derivation from haplorhine ancestors that retained many prosimian-like features.

ERRATUM: new body mass estimates for omomys carteri, a middle eocene primate from north america. Am J phys anthropol 109:41-52

Payseur BA, Covert HA, Vinyard CJ, Dagosto M. 1999. New Body Mass Estimates for Omomys carteri, a Middle Eocene Primate From North America. Am J Phys Anthropol 109:41-52. This article included an incomplete Table 2. The final two columns, showing "Intercept" and "SEE" data were omitted. The complete Table 2, with these two columns included, is provided below.

New body mass estimates for Omomys carteri, a middle Eocene primate from North America.

We report new body mass estimates for the North American Eocene primate Omomys carteri. These estimates are based on postcranial measurements and a variety of analytical methods, including bivariate regression, multiple regression, and principal components analysis (PCA). All body mass estimation equations show high coefficients of determination (R2), and some equations exhibit low prediction errors in accuracy tests involving extant species of body size similar to O. carteri. Equations derived from PCA-summarized data and multiple regression generally perform better than those based on single variables. The consensus of estimates and their statistics suggests a body mass range of 170-290 g. This range is similar to previous estimates for this species based on first molar area (Gingerich, J Hum Evol 10:345-374, 1981; Conroy, Int J Primatol 8:115-137, 1987).

Hindlimb suspension and hind foot reversal in Varecia variegata and other arboreal mammals.

The foot, perhaps more than any other region of the primate body reflects the interaction of positional behaviors with the geometric properties of available supports. The ability to reverse the hind foot during hindlimb suspension while hanging from a horizontal support or descending a large diameter vertical trunk has been noted in many arboreal mammals, including primates. Observations of Varecia variegata in the wild and under seminatural conditions document hindlimb suspension in this lemurid primate. The kinematics and skeletal correlates of this behavior are examined. Analogy is made with the form and function exhibited by nonprimate mammalian taxa employing this behavior. Examples of carnivores and rodents display very similar adaptations of the tarsals while other mammals, such as the xenarthrans, accomplish a similar end by means of different morphologies. However, a suite of features is identified that is shared by mammals capable of hind foot reversal. Hindlimb suspension effectively increases the potential feeding space available to a foraging mammal and represents a significant, and often unrecognized, alternative adaptive strategy to forelimb suspension and prehensile-tail suspension in primates.

Testing positional behavior of malagasy lemurs: a randomization approach.

Studies of primate positional behavior have only occasionally employed statistical testing because these data sets violate the assumptions underlying most standard statistical tests. As currently practiced, both common methods of collecting data on positional behavior involve sequential observations of a limited number of individuals, leading to data sets consisting of interdependent observations. Data collected from sequential observations may not be as dependent as currently accepted; however, approaches are available to deal with such data. Some previously applied tests are discussed, and an alternative strategy, a randomization test, is demonstrated. Randomization tests are based on observed rather than theoretical distributions. Thus, they are robust when applied to data sets which do not adhere to the strict assumptions inherent in standard tests. Randomization procedures suggested by Manly ([1991] Randomization and Monte Carlo Methods in Biology [New York: Chapman and Hall]) and Edgington ([1987] Randomization Tests [New York: Marcel Dekker, Inc.]) are applied to data collected for three species of lemurs studied at Ranomafana National Park, Madagascar (Lemur fulvus, Lemur rubriventer, and Lemur variegatus). Standard chi-square tests indicate statistically significant differences between these species in nearly all aspects of locomotor, postural, and substrate use behavior. In contrast, the randomization tests showed a significant difference only in the postures used by these lemurs. Lemur variegatus uses hindlimb suspensory postures much more often than L. fulvus or L. rubriventer, and the latter species use vertical clinging more often than L. variegatus. The results from the randomization tests are considered more reliable because by using individuals rather than observations as the units compared, they limit the problem of interdependence of observations and thus provide a conservative test. The particular randomization tests used also explicitly test the proposition that individuals of a species are more similar to each other than to individuals of other species. The lack of significant results is not surprising in light of the small number of individuals studied and the great deal of variability within a species for most of the variables considered.

Interrelationships among primate higher taxa.

One of the most controversial issues in primate palaeontology concerns the phylogenetic position of the extinct primate infraorder Adapiformes. During the Eocene, this group of primates of modern aspect possessed a holarctic distribution, and may have been present in the poorly known Palaeogene of Africa. Mainly on the basis of craniodental morphology, at least four hypotheses have been proposed concerning the phylogenetic interrelationships among adapiforms and other primate higher taxa: (1) that adapiforms are ancestral to both lemuriforms (including Lorisoidea) and anthropoids; (2) that adapiforms cannot be shown to possess a special phylogenetic relationship with either lemuriforms or anthropoids; (3) that adapiforms are the sister taxon of lemuriforms; and (4) that Adapiformes is not a natural, monophyletic group, but rather consists of nested clades within the radiation of lemuriforms. Here, we describe features of the ankle and wrist joints of several adapiform taxa that provide an independent test of the preceding hypotheses. These traits suggest that lemuriforms are monophyletic with respect to known adapiforms, but that adapiforms nevertheless are their stem lineage (sensu Ax).

Locomotor adaptations as reflected on the humerus of paleogene primates.

Examination of Paleogene distal humeri and a survey of homologous articulations in living primates allows some anatomical correlation with elbow mechanics and the occurrence of these during specific locomotor behaviors in living species. Claw climbing is postulated to be the ancestral primate locomotor mode from which the ancestral euprimate (strepsirhines and haplorhines) evolved a grasp leaping locomotor pattern. This pattern, which depends on a powerful grasp either during climbing or when landing after a jump, is still the most pervasive form of primate locomotion. Morphological evidence of Paleogene humeri suggest that vertical clinging and leaping behavior derived from grasp leaping at least six times independently.