A new therian mammal from the Rhaetic locality of Saint-Nicolas-de-Port (France)

In this paper a new taxon of Kuehneotheriidae is described and diagnosed, mainly by comparison with the genus Kuehneotherium . By its greater age and its more primitive evolutionary state, Woutersia mirabilis gen. et sp. nov. is a particularly interesting element of the fauna and enlarges the concept of the Kuehneotheriidae.
Dans cet article est dAecrit et défini un nouveau taxon de Kuehneotheriidés, Woutersia mirabilis gen. et sp. nov., par comparaison avec Kuehneotherium . Son âge plus ancien et son stade évolution considéré comme plus primitif en font un élément particuliérement intéressant, qui élargit en outre le concept des Kuehneotheriidés.     

Relationship between age and deposit of peritubular dentine

Peritubular dentine is a mineralised deposit formed centripetally in the dentine tubules with advancing age, so that the tubular diameter is smaller in teeth from older persons. The aim of the present study was to investigate the relationship between age in humans and the amount of peritubular dentine and the extent of the consequent obliteration of the tubules, and to find out whether this relationship was strong enough to be used as a parameter for age estimation. Fifty mandibular central and lateral human incisors were ground on the lingual aspect of the root and examined in a scanning electron microscope (SEM). The number of open tubules was counted and the diameter of the tubules measured both before and after etching with 35% orthophosphoric acid. The difference in the number of tubules in unetched and etched specimens was taken to be the number of occluded tubules, and the difference in radii before and after etching to be the thickness of peritubular dentine. The results did not demonstrate a significant relationship between age and the reduction in the number of tubules. One explanation might be that a certain age has to be reached before obliterated dentine tubules can be observed. The correlation between age and the thickness of peritubular dentine was not significant in teeth extracted because of periodontal disease, so these teeth were excluded from the regression analysis with age as the dependent variable. Only the thickness of peritubular dentine was included in the regression (r=0.69); this factor was a better indicator of age than the tubular diameter, but not so closely related to age that it can be recommended for general use in forensic and archaeological age estimations.     

Puncture-Resistance of Gloves for Handling Bats

ABSTRACT We quantified protection given by a variety of gloves against bat bites by using steel indenters to simulate teeth and measuring forces needed to puncture the gloves. Level of protection given by gloves was compared to expected bite forces and tooth sharpness of bats. Cotton, plastic-coated synthetic fabric, and proprietary materials advertised as puncture- and cut-resistant were easy to penetrate compared to leather gloves. Split leather gives the highest level of protection, but with reduced dexterity. These are best for handling larger bats (>40 g) or if higher safety is preferred. Deerskin gives reasonable protection without much loss in dexterity for handling bats <40 g.     

Intrastriatal transplantation of stem cells from human exfoliated deciduous teeth reduces motor defects in Parkinsonian rats

Background

This study explored the neural differentiation and therapeutic effects of stem cells from human exfoliated deciduous teeth (SHED) in a rat model of Parkinson's disease (PD).

Abnormal births and other “ill omens”

We summarize the ethnographic literature illustrating that “abnormal birth” circumstances and “ill omens” operate as cues to terminate parental investment. A review of the medical literature provides evidence to support our assertion that ill omens serve as markers of biological conditions that will threaten the survival of infants. Daly and Wilson (1984) tested the prediction that children of demonstrably poor phenotypic quality will be common victims of infanticide. We take this hypothesis one stage further and argue that some children will be poor vehicles for parental investment yet are not of demonstrably poor quality at birth. We conclude that when people dispose of infants due to “superstitious beliefs” they are pursuing an adaptive strategy in eliminating infants who are poor vehicles for parental investment. Catherine Hill lectures in biological anthropology/human sciences at Durham University’s University College, Stockton. She trained in biological anthropology at University College, London. Her current research interests include human and nonhuman primate socioecology and human resource ecology and development issues. Helen Ball lectures in biological anthropology/human sciences at Durham University’s University College, Stockton. She trained in biological anthropology at the University of Massachusetts at Amherst. Her current research interests include nonhuman primate behavior and socioecology, reproductive biology, and evolutionary issues.     

NEOSELACHIAN SHARK AND RAY TEETH FROM THE VALANGINIAN, LOWER CRETACEOUS, OF WĄWAŁ, CENTRAL POLAND

Abstract:  Valanginian strata at Wąwał in central Poland have yielded the oldest marine neoselachian assemblages from the Cretaceous of Europe. The faunas comprise seven taxa including Heterodontus polonicus sp. nov., an indeterminate orectolobiform, Protolamna sp., Palaeoscyllium sp., Synechodus nitidus , Squatina cranei and Belemnobatis sp. Heterodontus polonicus is recognized primarily by the high amount of reticulate ornamentation on the lower labial side of the anterior teeth. The faunas from Wąwał are numerically dominated by neoselachian genera such as Synechodus , Heterodontus and Belemnobatis that were already well established in the Jurassic. More modern taxa include the oldest recorded occurrence of the true Squatina -lineage, and the presence of Protolamna is one of the earliest undoubted lamniform occurrences so far reported.     

Primary teeth in Anura are nonpedicellate and bladed

1. Scanning electron microscop of the dentition of four anuran species (Discoglossus pictus, Bombina orientalis, Rana cyanophlyctis, Rana temporaria) revealed that at least the primary teeth, which are established during metamorphosis, are more or less bicuspid, bladed and nonpedicel-late. Juveniles and adults, however, have pedicellate teeth. 2. Thus, regardin the pedicellate condition, the sequence of stages in tooth development of Anura und Urodela show some similarities, although the primary teeth of urodeles develop already before metamorphosis.     

Mineral metabolism and microstructural defects in primate teeth.

There are numerous structural defects that occur in primate teeth due to variable calcification during certain growth stages. These interruptions are usually areas of hypomineralization in enamel and dentin which are referred to as Striae of Retzius and Hunter Shreger bands in the enamel or Incremental Lines of von Ebner and Contour Lines of Owen in the case of the dentin. The frequency of occurrence of these variations in mineralization can be related to such factors as growth tempo, dietary quality, state of health, and past disease episodes. Another structure that appears in the dentin is a region that fails to calcify and is referred to as Inter-globular Dentin. Our studies have shown that the microstructural quality of different species' dentition varies widely. Samples obtained from certain fre-ranging cercopithcoids show that these species have the least hypomineralizations while man has the most. Other primate species range between these two extremems with the pongids nearer to man in these characteristics, as previously noted by Sognnaes. Additionally, out initial study shows a great deal of diversity between prehistoric human populations in the microstructural quality of their teeth. We offer the tentative explanation that this variation is due to differences in the calcitying properties of the diet and hence a difference in the general state of their health.