The ants of the genus Protalaridris are revised based upon their morphology. Seven species are recognized; the type species (P. armata Brown, 1980) and six species described as new: P. aculeata Lattke & Alpert, sp. n., P. arhuaca Guerrero, Lattke & Alpert, sp. n., P. bordoni Lattke, sp. n., P. leponcei Delsinne & Lattke, sp. n., P. loxanensis Lattke, sp. n., and P. punctata Lattke, sp. n. The genus is patchily distributed in mesic forested areas from western Panama to northern Venezuela and along the Andes to the Amazon watershed of southwestern Peru. The generic description is modified to accommodate a short-mandibulate species. Sporadic biological observations of one long-mandibulate species suggest they are sit-and-wait ambush predators that open their jaws to approximately 180° when stalking. All species are described and imaged, an identification key and a distribution map is provided. Comparing the mandibular morphology of long-mandibulate Protalaridris with other extant and extinct ants bearing elongate, dorsoanterior arching mandibles suggests the supposed mandibular apex in these taxa is actually a hypertrophied, preapical tooth and their supposed basal mandibular tooth is the main mandibular shaft., John E. Lattke, Thibaut Delsinne, Gary D. Alpert, Roberto J. Guerrero., and Obsahuje bibliografii
The presented work follows the first part [1], which is focused on the analysis of bone tissue in terms of dependence of bone tissue 'quality' and its subsequent behaviour based on the stress around the disk implant when biting.
This second part is focused on the stress-strain analysis (and tolerability) of disk implants as loaded during the masticating process.
The study includes two types of disk implants (single-disk and double-disk), three types of anchorage, four degrees (stages) of osseointegration in three quality degrees of the cancellous bone. The study, as expected, has shown that the problematic area of he implants is a transition between the implant body and the disk component, where the equivalent stress in the analyzed implants reaches 700 MPa. and Obsahuje seznam literatury
Morphometric skull variation was studied in Rhinolophus mehelyi, R. euryale and R. blasii by means of 50 cranial, mandibular and dental measurements. In R. euryale differences between age groups (subadults, adults and old adults) were not significant. Poorly pronounced sexual dimorphism (male skulls were, on average, larger than those of females in some measurements) and low geographical variability within Bulgaria were observed in R. euryale. We propose a simple biplot (length of cheek teeth against the rostral posterior width), a stepwise discriminant analyses of some criteria and numerical keys that allow the clear determination of crania or their parts. A large additional sample of incomplete crania was determined on the basis of these keys which, in turn, allow data to be obtained on species distribution patterns. Rhinolophus euryale is the most frequent and probably the most abundant horseshoe bat species examined, and occurs throughout Bulgaria. Rhinolophus mehelyi is widespread but appears to be relatively rare. Rhinolophus blasii is confined mainly to the southern regions of Bulgaria, but may be abundant locally.
The research was aimed at examining 230 skulls and mandibles (113 males and 117 females) of the red fox (Vulpes vulpes) in the territory of the Republic of Lithuania. The object of the study was macroscopic evaluation of dental and periodontal pathologies, including changes in the structure of the skull and mandible. The most common teeth pathology was indicated to be hypodontia 13.27% in males and 5.98% in females (excluding M3 molar tooth). The hypodontia of the M3 was found to be common in males 6.19% and 7.69% in females. The findings of the research reveal that pathologies such as hyperdontia, dental fractures, enamel hypoplasia, abrasion, periodontitis stage 3 and stage 4 were less common: 1-4% in both males and females. In four skulls and mandibles of females a complex of severe pathologies of teeth and periodontium were found. There were no similar cases observed in males. This was the only significant difference between males and females. Other pathologies, including fractures of the skull or mandible, atypical form of foramen magnum, and changes in bone structure were rare overall, though slightly more common in males but not significantly.
Males in many beetles show horn or mandible dimorphism. The stag beetle Dorcus rectus was assumed to have dimorphic males, but in this species there are not two but three visually distinct mandibular phenotypes. The aim of this study is to determine if the three phenotypes represent an allometric trimorphism in this species by studying the scaling relationship between body length and mandible length in 148 adult males and 31 adult females. The relationship was fitted using the following four statistical models; a simple line, a logistic curve, a continuous segmented line and a discontinuous line. The best-fitting model for the males was a discontinuous line with two break points and that for the females a simple line. The male data was also well fitted by a logistic curve. The discontinuous linear model divided the males into three groups that were in good agreement with the three phenotypes. These results suggest that a subtle allometric trimorphism possibly exists in males of this species. Small males of this species have no distinct teeth on their mandibles, whereas small males of D. striatipennis and D. curvidens, which are closely related to D. rectus, have a pair of distinct teeth on their mandibles. The phylogenetic relationship of these Dorcus species suggests that the trimorphism in D. rectus may have arisen through the loss of teeth in small males., Yutaka Iguchi., and Obsahuje seznam literatury
The purpose of the study was to test the hypothesis of different distribution spaces of elements in the rat mandibular bone and teeth. We used six adult males of Wistar laboratory rats for the study. After killing the animals, we extracted the molars and removed incisor crowns. The mandibular bone was divided into four parts (mesial-central-distal-ridge). Inductively coupled plasma mass spectrometry was used to determine the presence of 41 elements in the bone and tooth. Evidence of 14 elements was found in all samples (incisors-molars-bone). Generally, significant differences between the left and right side were found for K and Rb in the bone locations. As regards statistically significant differences in incisors-molars-bone locations, the elements for which these differences were found for all comparisons are listed as incisors versus individual molars, incisors versus bone locations, and individual molars versus bone locations: a) incisors-molars: Ba, Mn, Mo, Sr, Zn, K, Mg and Rb; b) incisors-bone: Fe, K, Mg, Mn, Na, Zn and Ba; c) molars-bone: Mn, Mo, Na and Mg. Statistically significant differences were also found between molars for Fe, Mg, Mn, and Sr and between bone locations for Ba, Ca, Mn, Sr, K, Rb, Zn, Mo, Mg, and Na. The elements Cu, Ni and Co were without pronounced differences. Twenty-seven elements were below the detection limit. Our results indicate different distributions of some elements in the rat mandibular incisors-molars-bone. We assume that the knowledge of chemical element contents in the laboratory rat bone and teeth will prove useful in experimental research of both these hard tissues. and Corresponding author: Ivo Němec