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Strepsirrhine Primates (strepsirrhine + primate)
Selected AbstractsNew strepsirrhine primate from the late Eocene of Peninsular Thailand (Krabi Basin)AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2006Laurent Marivaux Abstract In this paper, we describe the newly discovered lower jaw of a primate from the late Eocene Krabi coal mine (Bang Mark pit) of Peninsular Thailand. We performed microtomographic examinations at the European Synchrotron Radiation Facility (ESRF, Grenoble, France) to analyze different morphological aspects of the jaw and teeth. Although partially preserved, this fossil mandible reveals a set of distinctive dental traits (e.g., double-rooted P2 and molarized P4) that allow us to describe a new stepsirrhine adapiform: Muangthanhinius siami, new genus and species. This taxon is somewhat atypical among Paleogene adapiforms, and more specialized than the sivaladapid adapiforms (hoanghoniines) that existed in Asia in the same epoch. In fact, Muangthanhinius shows a degree of dental specialization approximating that of some modern strepsirrhine lemuriforms, although it lacks the highly specialized anterior dentition characterizing this living primate group (canine + incisors forming a very procumbent toothcomb). In contrast, Muangthanhinius exhibits a large canine deeply anchored within the dentary that probably protruded high above the toothrow. Finally, despite the development of a molarized P4 as in Miocene sivaladapid sivaladapines, Muangthanhinius differs in molar morphology from this group, and the position of this new taxon within the Adapiformes remains indeterminate. Clarification of its phylogenetic position will require more morphological evidence than is currently available. Am J Phys Anthropol, 2006. © 2006 Wiley-Liss, Inc. [source] Maximum ingested food size in captive strepsirrhine primates: Scaling and the effects of dietAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2010Jonathan M.G. Perry Abstract Little is known about ingested food size (Vb) in primates, even though this variable has potentially important effects on food intake and processing. This study provides the first data on Vb in strepsirrhine primates using a captive sample of 17 species. These data can be used for generating and testing models of feeding energetics. Strepsirrhines are of interest because they are hypometabolic and chewing rate and daily feeding time do not show a significant scaling relationship with body size. Using melon, carrot, and sweet potato we found that maximum Vb scales isometrically with body mass and mandible length. Low dietary quality in larger strepsirrhines might explain why Vb increases with body size at a greater rate than does resting metabolic rate. Relative to body size, Vb is large in frugivores but small in folivores; furthermore scaling slopes are higher in frugivores than in folivores. A gross estimate of dietary quality explains much of the variation in Vb that is not explained by body size. Gape adaptations might favor habitually large bites for frugivores and small ones for folivores. More data are required for several feeding variables and for wild populations. Am J Phys Anthropol 142:625,635, 2010. © 2010 Wiley-Liss, Inc. [source] Host intrinsic determinants and potential consequences of parasite infection in free-ranging red-fronted lemurs (Eulemur fulvus rufus)AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2010Dagmar Clough Abstract Parasites and infectious diseases represent ecological forces shaping animal social evolution. Although empirical studies supporting this link abound in various vertebrate orders, both the study of the dynamics and impact of parasite infections and infectious diseases in strepsirrhine primates have received little empirical attention. We conducted a longitudinal parasitological study on four groups of wild red-fronted lemurs (Eulemur fulvus rufus) at Kirindy Forest, Madagascar, during two field seasons in consecutive years to investigate i) the degree of gastrointestinal parasite infection on population and individual levels and ii) factors potentially determining individual infection risk. Using a comprehensive dataset with multiple individually assignable parasite samples as well as information on age, sex, group size, social rank, and endocrine status (fecal androgen and glucocorticoid), we examined parasite infection patterns and host traits that may affect individual infection risk. In addition, we examined whether parasite infection affects mating and reproductive success. Our results indicated high variability in parasite infection on individual and population levels. Time of year and group size was important determinants of variability in parasite infection. Variation in hormone levels was also associated with parasite species richness and parasite infection intensity. Differences in parasite infection between years indicate a potential immune-enhancing function of steroid hormones on nematode infections, which has not been reported before from other vertebrates studied under natural conditions. Male mating and reproductive success were not correlated to any measure of parasite infection, which suggests a nonfunctional role of the parasites we examined in primate sexual selection. Am J Phys Anthropol, 2010. © 2010 Wiley-Liss, Inc. [source] Scaling of the first ethmoturbinal in nocturnal strepsirrhines: Olfactory and respiratory surfacesTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 3 2007Timothy D. Smith Abstract Turbinals (scroll bones, turbinates) are projections from the lateral wall of the nasal fossa. These bones vary from simple folds to branching scrolls. Conventionally, maxilloturbinals comprise the respiratory turbinals, whereas nasoturbinals and ethmoturbinals comprise olfactory turbinals, denoting the primary type of mucosa that lines these conchae. However, the first ethmoturbinal (ETI) appears exceptional in the variability of it mucosal covering. Recently, it was suggested that the distribution of respiratory versus olfactory mucosae varies based on body size or age in strepsirrhine primates (lemurs and lorises). The present study was undertaken to determine how the rostrocaudal distribution of olfactory epithelium (OE) versus non-OE scales relative to palatal length in strepsirrhines. Serially sectioned heads of 20 strepsirrhines (10 neonates, 10 adults) were examined for presence of OE on ETI, rostral to its attachment to the nasal fossa wall (lateral root). Based on known distances between sections of ETI, the rostrocaudal length of OE was measured and compared to the length lined solely by non-OE (primarily respiratory epithelium). In 13 specimens, the total surface area of OE versus non-OE was calculated. Results show that the length of non-OE scales nearly isometrically with cranial length, while OE is more negatively allometric. In surface area, a lesser percentage of non-OE exists in smaller species than larger species and between neonates and adults. Such results are consistent with recent suggestions that the olfactory structures do not scale closely with body size, whereas respiratory structures (e.g., maxilloturbinals) may scale close to isometry. In primates and perhaps other mammals, variation in ETI morphology may reflect dual adaptations for olfaction and endothermy. Anat Rec, 2007. © 2007 Wiley-Liss, Inc. [source] A comparison of auditory brainstem responses and behavioral estimates of hearing sensitivity in Lemur catta and Nycticebus coucangAMERICAN JOURNAL OF PRIMATOLOGY, Issue 3 2010Marissa A. Ramsier Abstract Primates depend on acoustic signals and cues to avoid predators, locate food, and share information. Accordingly, the structure and function of acoustic stimuli have long been emphasized in studies of primate behavioral and cognitive ecology. Yet, few studies have addressed how well primates hear such stimuli; indeed, the auditory thresholds of most primate species are unknown. This empirical void is due in part to the logistic and economic challenges attendant on traditional behavioral testing methods. Technological advances have produced a safe and cost-effective alternative,the auditory brainstem response (ABR) method, which can be utilized in field conditions, on virtually any animal species, and without subject training. Here we used the ABR and four methods of threshold determination to construct audiograms for two strepsirrhine primates: the ring-tailed lemur (Lemur catta) and slow loris (Nycticebus coucang). Next, to verify the general efficacy of the ABR method, we compared our results to published behaviorally-derived audiograms. We found that the four ABR threshold detection methods produced similar results, including relatively elevated thresholds but similarly shaped audiograms compared to those derived behaviorally. The ABR and behavioral absolute thresholds were significantly correlated, and the frequencies of best sensitivity and high-frequency limits were comparable. However, at frequencies ,2,kHz, ABR thresholds were especially elevated, resulting in decreased agreement with behavioral thresholds and, in Lemur, the ABR 10-dB range starting points were more than 2 octaves higher than the behavioral points. Finally, a comparison of ABR- and behaviorally-derived audiograms from various animal taxa demonstrates the widespread efficacy of the ABR for estimating frequency of best sensitivity, but otherwise suggests caution; factors such as stimulus properties and threshold definition affect results. We conclude that the ABR method is a promising technique for estimating primate hearing sensitivity, but that additional data are required to explore its efficacy for estimating low-frequency thresholds. Am. J. Primatol. 72:217,233, 2010. © 2009 Wiley-Liss, Inc. [source] | ||||||||||