bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mandibular growth and function in Archaeolemur
Authors: Ravosa Matthew J. , Simons Elwyn L. 
Published: February 2006

AbstractOntogenetic changes in the morphology of the mandibular symphysis are described in Archaeolemur so as to infer the functional significance of symphyseal fusion in this subfossil Malagasy lemur. The first regions of the symphysis to show a more complex morphology were the lower and anterior borders of the joint and, to a lesser extent, the lingual borders of the superior and inferior transverse tori. During growth, these regions became increasingly rugose and encroached upon a centrally located, smooth, “oval” region, which may have been a principal pathway for neurovascular structures communicating with the unfused joint. In subadults, the symphysis was completely fused except for the lingual surface of the inferior transverse torus, where a patent suture and potential space were present between dentaries. Thus, in Archaeolemur there was an age‐ and size‐related pattern of increased symphyseal ossification or fusion that was complete by adulthood.The morphology of the interlocking bony processes and the sequence of ossification in the symphysis suggest that increased dorsoventral shear stress during mastication was the most likely determinant of symphyseal fusion in Archaeolemur: The allometric pattern of greater symphyseal fusion may be linked to the presence of relatively greater dorsoventral shear in adults due to an increased recruitment of balancing‐side jaw‐muscle force. There is little indication that the symphysis of juvenile Archaeolemur was buttressed to resist forces associated with “wishboning” during mastication or vertical bending during incision. Our observations, as well as those of others, suggest that symphyseal fusion in primates occurs initially as a response to increased dorsoventral shear during mastication. Therefore, wishboning stress might only become a major determinant of symphyseal form and function in those taxa that develop a fused symphysis to counter increased dorsoventral shear. © 1994 Wiley‐Liss, Inc.
Paranthropus boisei: An example of evolutionary stasis?
Authors: Wood Bernard , Wood Christopher , Konigsberg Lyle 
Published: February 2006

AbstractOf the presently recognised early hominid species, Paranthropus boisei is one of the better known from the fossil record and arguably the most distinctive; the latter interpretation rests on the numbers of apparently derived characters it incorporates. The species as traditionally diagnosed is distributed across approximately one million years and is presently confined to samples from East African sites. The hypodigm has been examined for evidence of intraspecific phyletic evolution, with particular emphasis on the areas best represented in the fossil record, namely the teeth and mandible. The results of this examination of 55 mandibular and dental variables, which uses the Γ test statistic for the detection of trend, and nonparametric spline regression (Loess regression) for investigating pattern and rate of temporal change, show that within Paranthropus boisei sensu stricto most evidence of temporally related morphological trends relates to the morphology of the P4 crown. There is little or no evidence of any tendency to increase in overall size through time. Fossils from the Omo Shungura Formation and West Turkana which have been recovered from a time period earlier than the P. boisei sensu stricto hypodigm resemble the latter taxon in some features, but differ from it in aspects of cranial morphology. There is insufficient fossil evidence of the earlier taxon to tell whether it changes through time, but when trends of 47 mandibular and dental variables are assessed across the combined East African “robust” australopithecine sample, there is evidence for a relatively abrupt change around 2.2–2.3 Myr in approximately 25% of the dental and mandibular remains. Some of these changes correspond with the temporal trends within P. boisei sensu stricto, but others, such as mandible height, do not. If the earlier material is ancestral to P. boisei sensu stricto, evidence from the teeth and jaws is consistent with a punctuated origin for the latter taxon. © 1994 Wiley‐Liss, Inc.
Genetic variation in North Africa and Eurasia: Neolithic demic diffusion vs. paleolithic colonisation
Authors: Barbujani Guido , Pilastro Andrea , De Domenico Silvia , Renfrew Colin 
Published: February 2006

AbstractThe hypothesis that both genetic and linguistic similarities among Eurasian and North African populations are due to demic diffusion of neolithic farmers is tested against a wide database of allele frequencies. Demic diffusion of farming and languages from the Near East should have determined clines in areas defined by linguistic criteria; the alternative hypothesis of cultural transmission does not predict clines. Spatial autocorrelation analysis shows significant gradients in three of the four linguistic families supposedly affected by neolithic demic diffusion; the Afroasiatic family is the exception. Many such gradients are not observed when populations are jointly analyzed, regardless of linguistic classification. This is incompatible with the hypothesis that major cultural transformations in Eurasia (diffusion of related languages and spread of agriculture) took place without major demographic changes. The model of demic diffusion seems therefore to provide a mechanism explaining coevolution of linguistic and biological traits in much of the Old World. Archaeological, linguistic, and genetic evidence agree in suggesting a multidirectional process of gene flow from the Near East in the neolithic. However, the possibility should be envisaged that some allele frequency patterns can predate the neolithic and depend on the initial spread of Homo sapiens sapiens from Africa into Eurasia. © 1994 Wiley‐Liss, Inc.
Inflammatory lesions of ribs: An analysis of the Terry Collection
Authors: Roberts Charlotte , Lucy David , Manchester Keith 
Published: February 2006

AbstractThe aim of this paper is to consider the diagnostic criteria for tuberculosis in ancient populations. It investigates the frequency of periosteal new bone formation on the visceral surfaces of ribs from 1718 individuals from the Terry Collection, Smithsonian Institution, Washington D. C. and attempts to determine the aetiological factors producing these lesions. Numbers of individuals with lesions according to cause of death were recorded and the patterning of lesions compared between people who had died from tuberculosis and those whose cause of death was unrelated to a pulmonary disease. Rib lesions were more common in individuals dying from tuberculosis (61.6% or 157 of 255) than in individuals dying from other causes (15.2% or 165 of 1086). It is suggested that tuberculosis at a peripheral lung focus may disseminate directly through the pleura to the visceral surfaces of the ribs, or that pulmonary tuberculosis may be the cause of empyema of the pleural cavity and that this, per se, may initiate inflammatory change on the visceral surfaces of ribs. The nonrecognition or description of these often very subtle proliferative lesions on ribs by radiological examination of tuberculous victims is significant in the discussion of bone changes in tuberculosis. The possibility that individuals with no recorded history of tuberculosis at death actually suffered from the disease was considered in light of the frequency of rib lesions and noncorrelation with a tuberculous cause of death. Differential diagnoses are discussed including the possibility that the lesions represent a general nonspecific indicator of stress. © 1994 Wiley‐Liss, Inc.
Enamel microstructure in lemuridae (mammalia, primates): Assessment of variability
Authors: Maas Mary C. 
Published: February 2006

AbstractThis study describes the molar enamel microstructure of seven lemurid primates: Hapalemur griseus, Varecia variegata, Lemur catta, Lemur macaco, Lemur fulvus rufus, Lemur fulvus fulvus, and Lemur fulvus albifrons. Contrary to earlier accounts, which reported little or no prism decussation in lemurid enamel, both Lemur and Varecia molars contain a prominent inner layer of decussating prisms (Hunter‐Schreger bands), in addition to an outer radial prism layer, and a thin, nonprismatic enamel surface layer. In contrast, Hapalemur enamel consists entirely of radial and, near the surface, nonprismatic enamel. In addition, for all species, prism packing patterns differ according to depth from the tooth surface, and for all species but Varecia (which also has the thinnest enamel of any lemurid), average prism area increases from the enamel‐dentine junction to the surface; this may be a developmental solution to the problem of accommodating a larger outer surface area with enamel deposited from a fixed number of cells. Finally, contradicting some previous reports, Pattern 1 prisms predominate only in the most superficial prismatic enamel. In the deeper enamel, prism cross‐sections include both closed (Pattern 1) and arc‐shaped (Pattern 2 or, most commonly, Pattern 3). This sequence of depth‐related pattern change is repeated in all taxa. It should also be emphasized that all taxa can exhibit all three prism patterns in their mature enamel. The high degree of quantitative and qualitative variation in prism size, shape, and packing suggests that these features should be used cautiously in phylogenetic studies.Hapalemur is distinguished from the other lemurids by unique, medially constricted or rectangular prism cross‐sections at an intermediate depth and the absence of prism decussation, but, without further assessment of character polarity, these differences do not clarify lemurid phylogenetic relations. Some characters of enamel microstructure may represent synapomorphies of Lemuridae, or of clades within Lemuridae, but homoplasy is likely to be common. Homoplasy of enamel characters may reflect functional constraints. © 1994 Wiley‐Liss, Inc.
Phylogenetic, paleodemographic, and taphonomic implications of Victoriapithecus deciduous teeth from Maboko, Kenva
Authors: Benefit Brenda R. 
Published: February 2006

AbstractMore than 240 milk teeth of Victoriapithecus macinnesi, representing all elements of the deciduous dentition, are described. Their morphology is intermediate between that of hominoids and cercopithecids. Unlike colobine and cercopithecine milk teeth, Victoriapithecus dp3s, dp4s, and at least 7 (14%) dp4s lack transverse distal loph(id)s and are not bilophodont. Victoriapithecus also differs from cercopithecids in having less elongated deciduous premolars, a dp3 metacone set mesial to a very small hypocone, a dp4 crista obliqua, and a dp4 hypoconulid. The deciduous canines and incisors of Victoriapithecus are like those of other cercopithecids in having an uneven distribution of enamel around a compressed (rather than cylindrical) root, but differ from cercopithecids and resemble hominoids in being more elongated. Since Colobinae and Cercopithecinae share features of the deciduous dentition that are derived relative to Victoriapithecus and hominoids, extant Old World monkeys are interpreted as representing the sister‐taxon of the middle Miocene cercopithecoids.Due to a dramatic increase in the number of deciduous teeth found at Maboko Island, juvenile individuals represent a much larger proportion of recently excavated Victoriapithecus collections than is true of pre‐1987 assemblages which mainly derive from sediment first excavated during the 1930s and 1940s. Age distribution differences between pre‐ and post‐1987 samples indicate that paleontological collection procedures were more important than taphonomic biases in determining the paleodemographic profile of the Maboko fossils.Since the Victoriapithecus assemblage from Maboko is strikingly similar to that of fossil Theropithecus oswaldi from Olorgesailie in terms of the large number of specimens and high representation of juvenile and infant individuals, the latter can no longer be viewed as unique among cercopithecoid fossil assemblages. Rather than being related to a specific cause of death, such as selective hunting of T. oswaldi by Homo (Shipman et al. [1981] Curr. Anthropol. 22:257–268), the large number of cercopithecoids at both sites is attributed to the fact that both assemblages represent excavated samples and that the preferred habitats of the extinct monkeys were probably at or near the site of deposition.The greater number of young adult male than female canines in the apparently attritional Maboko Bed 5 assemblage, indicate that the social organization of V. macinnesi may have been similar to that of modrn macaques, with males migrating out of their natal group and suffering higher death rates than females at puberty. © 1994 Wiley‐Liss, Inc.
“Giant” tamarin from the Miocene of Colombia
Authors: Kay Richard F. 
Published: February 2006

AbstractA nearly complete but badly crushed skull and mandible of Lagonimico conclucatus, gen. et sp. nov. is described from the La Victoria Formation, Colombia. The specimen is of middle Miocene age and dates from about 13.5 Ma. Features of the dentition suggest Lagonimico is a sister group to living Callitrichinae (Saguinus, Leontopithecus, Callithrix, and Cebuella). These features include having elongate compressed lower incisors, a reduced P2 lingual moiety, and the absence of upper molar hypocones. The new taxon also has autapomorphies, such as a relatively deep jaw, that rule it out of the direct ancestry of any living callitrichine. This animal is assigned to a new tribe of the callitrichine clade.The orbits of L. conclucatus are small, suggesting diurnal habits. Inflated, low‐crowned (bunodont) cheek teeth with short, rounded shearing crests, as well as premolar simplification and M3 size reduction, suggest fruit‐ or gumeating adaptations, as among many living callitrichines. Procumbent and slightly elongate lower incisors suggest this species could use its front teeth as a gouge, perhaps for harvesting tree gum. Estimates from jaw size suggest Lagonimico weighed about 1,200 g, about the size of Callicebus, the living titi monkey of South America. Judged from tooth size and jaw length, Lagonimico would have been slightly smaller than Callicebus, but still larger than Callimico or any living callitrichine. Therefore, many of the distinctive anatomical features of the callitrichine clade, sometimes explained by phyletic dwarfing, may have evolved at larger body size. Evolutionary size reduction may have occurred in parallel in callitrichines and Callimico. © 1994 Wiley‐Liss, Inc.
Frequency and chronological distribution of dental enamel hypoplasia in enslaved African Americans: A test of the weaning hypothesis
Authors: Blakey Michael L. , Leslie Teresa E. , Reidy Joseph P. 
Published: February 2006

AbstractThe dentition of 27 enslaved African Americans from archaeological sites in Maryland and Virginia were examined. All 17 males and 7 of the 10 females in this study exhibited enamel hypoplastic defects indicative of systemic nutritional and disease stresses interfering with amelogenesis. Estimates of the ages of occurrence of these defects show that most occur between 1.5 and 4.5 years of age, 0.5–3.75 years later than historically documented weaning age (9–12 months of age) in similar plantation populations. Comparisons are made with studies of dental enamel hypoplasia in contemporaneous enslaved and free African American populations, including our data on 75 individuals from the First African Baptist Church cemetery in Philadelphia. These populations were highly stressed. While there appears to be a modest effect of early weaning stress, no direct relationship of peak frequencies to weaning age can be shown. These data raise questions about the attribution of peak hypoplasia frequencies to age at weaning or “post‐weaning” stresses in previous paleopathological studies. High hypoplasia frequencies during the middle years of enamel development are more likely the result of a combination of 1) multiple environmental stresses, 2) differences in hypoplastic susceptibility in enamel, and 3) random factors. © 1994 Wiley‐Liss, Inc.
Cranial variables as predictors of hominine body mass
Authors: Aiello Leslie C. , Wood Bernard A. 
Published: February 2006

AbstractBody mass is a key variable in investigating the evolutionary biology of the hominines (Australopithecus, Paranthropus, and Homo). It is not only closely related to life‐history parameters but also provides a necessary baseline for studies of encephalization or megadonty. Body mass estimates are normally based on the postcranial skeleton. However, the majority of hominid fossils are cranio‐dental remains that are unassociated with postcranial material. Only rarely can postcranial material be linked with craniodentally defined hominid taxa. This study responds to this problem by evaluating body mass estimates based on 15 cranial variables to determine whether they compare in reliability with estimates determined from postcranial variables.Results establish that some cranial variables, and particularly orbital area, orbital height, and biporionic breadth, are nearly as good mass predictors for hominoids as are some of the best postcranial predictors. For the hominines in particular, orbital height is the cranial variable which produces body mass estimates that are most in line with postcranially generated estimates. Both orbital area and biporionic breadth scale differently in the hominines than they do in the other hominoids. This difference in scaling results in unusually large estimates of body mass based on these variables for the larger‐sized hominines, although the three cranial variables produce equivalent predicted masses for the smaller‐bodied hominines. © 1994 Wiley‐Liss, Inc.
Further evidence of lead contamination of Omaha skeletons
Authors: Ghazi A. Mohamad , Reinhard Karl J. , Holmes Mary Anne , Durrance Eric 
Published: February 2006

AbstractA previous analysis of Omaha skeletons dating between A. D. 1780 and 1820 revealed the presence of lead in all skeletons with high concentrations in children and adult males (Reinhard and Ghazi [1992] Ann. J. Phys. Anthropol. 89:183–195). Two likely explanations for the high lead levels were presented: 1) metabolic absorption of lead and 2) diagenetic uptake of lead by the bones from postmortem application of pigments to the corpse. Two types of lead were available to the Omaha tribe: 1) Mississippi Valley type, and 2) non‐Mississippi Valley type. It has been suggested that red‐lead pigment mixed with mercury sulphide (cinnabar) applied to the corpse may have been one of the sources of lead found in bones. Further isotopic analyses of samples of pigment and metallic lead artifacts associated with the skeletons revealed that non‐Mississippi Valley type lead is present in the pigment while Mississippi Valley type lead comes from metallic artifacts. Both lead and mercury were found in the pigment samples, verifying that a lead‐based pigment mixed with cinnabar‐based pigment was used as a cosmetic by the Omaha. Isotopic analysis of lead in skeletons indicates that the pigment contributed most to lead content of bone. This new evidence clarifies the previous study and suggests specific mechanisms by which lead became incorporated into bone. © 1994 Wiley‐Liss, Inc.
A re‐evaluation of subspecific variation and canine dimorphism in woolly spider monkeys (Brachyteles arachnoides)
Authors: Leigh Steven R. , Jungers William L. 
Published: February 2006

AbstractA recent study suggests that differing populations of woolly spider monkeys exhibit a substantial degree of morphological, cytogenetic, and behavioral variation. We re‐evaluate the differences between populations in the degree of canine tooth height sexual dimorphism and in the frequency of thumbs. Statistical analysis of variation in the degree of canine sexual dimorphism between these populations fails to provide strong evidence for subspecific variation: differences in the degree of canine dimorphism cannot be considered statistically significant. Differences between populations in the frequency of thumbs are, however, statistically significant. The lack of clear distinctions between populations in the degree of canine dimorphism complicates assessments of behavioral variation between these populations. We suggest that the level of geographic variation in woolly spider monkey canine dimorphism is not consistent with subspecific status. © 1994 Wiley‐Liss, Inc.
Positional behavior in five sympatric old world monkeys
Authors: Gebo Daniel L. , Chapman Colin A. 
Published: February 2006

AbstractObservations of positional behavior and habitat use were recorded on focal individuals of five species of Old World monkeys at Kibale Forest, Uganda, through the dry season of 1990 and 1991. Cercopithecus ascanius, Cercopithecus mitis, Cercocebus albigena, Colobus badius, and Colobus guereza commonly utilize five similar types of positional behavior (i.e., quadrupedalism, leaping, climbing, sitting, and standing), but in varying frequencies and situations. As a group, colobines use oblique supports and leap more often, and cover greater linear distances during leaps than do cercopithecines. Colobines also prefer to sit (about 90% of all postures), while cercopithecines stand more frequently. Body size differences between the sexes of a species are not reflected in positional behavior. The two small‐bodied species climb more and leap less often than the three larger species, which is the reverse of what we would expect. Leaping is the most common method of crossing open spaces within the canopy; but most spatial gaps and leaps are over short distances, usually one meter or less. All five species, regardless of body size or the availability of forest supports, prefer mediumsized supports. Incorporating our work from Uganda with previous investigations of positional behavior reveals few consistent trends with respect to body size or habitat use across primates. © 1995 Wiley‐Liss, Inc.
Dust accumulation in the canopy: A potential cause of dental microwear in primates
Authors: Ungar Peter S. , Teaford Mark F. , Glander Kenneth E. , Pastor Robert F. 
Published: February 2006

AbstractDental microwear researchers consider exogenous grit or dust to be an important cause of microscopic wear on primate teeth. No study to date has examined the accumulation of such abrasives on foods eaten by primates in the forest. This investigation introduces a method to collect dust at various heights in the canopy. Results from dust collection studies conducted at the primate research stations at Ketambe in Indonesia, and Hacienda La Pacifica in Costa Rica indicate that 1) grit collects throughout the canopy in both open country and tropical rain forest environments; and 2) the sizes and concentrations of dust particles accumulated over a fixed period of time differ depending on site location and season of investigation. These results may hold important implications for the interpretation of microwear on primate teeth. © 1995 Wiley‐Liss, Inc.