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Isolated Teeth (isolated + tooth)
Selected AbstractsDesign Strategy of Minipig Molars Using Electronic Speckle Pattern Interferometry: Comparison of Deformation under Load between the Tooth-Mandible Complex and the Isolated Tooth,ADVANCED MATERIALS, Issue 4 2009Netta Lev-Tov Chattah Using electronic speckle pattern interferometry minipig molars were tested under load inside the bone socket and when embedded in a stiff polymer. It is demonstrated that the molar bends in the direction of the load in both configurations even at low loads. This shows that the intrinsic reaction of the tooth crown to load is complemented by the structures supporting the tooth. [source] Fish and ostracod remains from the Santos Basin (Cretaceous to Recent), BrazilGEOLOGICAL JOURNAL, Issue 4 2002C. Giles Miller Abstract For the first time, ichthyoliths are described from the Santos sedimentary basin, offshore southern Brazil. Isolated teeth, dermal scales and the first documented otoliths from Cretaceous (Albian) to Recent cuttings from five wells are described. The following groups are represented: Chondrichthyans: Triakidae, Carcharhinidae; Ginglymostomatidae: ?Ginglymostoma sp., Lamnidae indet., Scyliorhinidae; Osteichthyans: Teleostei; Myctophiidae: Diaphus aff. splendidus sp. complex, Diaphus spp., Diaphus cf. garmani, Ceratoscopelus aff. warmingii; Sternoptychidae: Valenciennellus tripunctulatus, teeth of indeterminate Teleostei. The majority of these ichthyofossils represent extant forms, known to occur in the Atlantic Ocean, and are of potential value for stratigraphical correlations between oil-yielding basins in the region. Ostracods are not well preserved but can be identified to generic level indicating marine environments. The ostracod faunas offer potential for intrabasinal correlation in the Eocene and Oligocene. Copyright © 2002 John Wiley & Sons, Ltd. [source] Lancetfish teeth (Neoteleostei, Alepisauroidei) from the Early Cretaceous of Alcaine, NE SpainLETHAIA, Issue 4 2003JÜRGEN KRIWET Isolated teeth of fossil lancetfishes (Neoteleostei, Alepisauroidei) are reported from Early Cretaceous strata of the Oliete subbasin (Iberian basin) in NE Spain. These are the oldest remains attributable to alepisauriform teleosts. The fossil-bearing strata are dated as lower Barremian. The teeth were recovered from shallow marine to lagoonal sediments. They closely resemble teeth of the fossil alepisauriforms Enchodus and Cimolichthys in overall morphology. The combination of fang-like morphology, sculpture consisting of apico-basal striations, postapical barb, absence of distal cutting edge, and wide pulp cavity surrounded by a rather thin layer of dentine is interpreted as the most basal tooth pattern in alepisauriforms. These remains may be isolated, but this study emphasizes the true value of such remains for palaeobiological studies, predicting the fossils provide characters for phylogenetic analyses. [source] The dentition of Goodrichthys, a Carboniferous ctenacanthiform shark from ScotlandACTA ZOOLOGICA, Issue 2009Michal Ginter Abstract Study of three sets of chondrichthyan teeth from the Mississippian (Viséan) of Glencartholm, Scotland, namely the dentition of the holotype of a ctenacanthiform shark Goodrichthys eskdalensis, the dentition of a recently found, yet undescribed shark (NMS 2000.14.2), and a group of isolated teeth probably found in a nodule, tentatively suggests that all of them represent the same species. The combined characters of these teeth show that the dentition of Goodrichthys was moderately heterodont, of a cladodont design, in which larger teeth may have had three, and smaller ones only two, lateral cusps on each side of a prominent, coarsely cristated median cusp. The base is similar to that of Cladodus and Famennian representatives of Ctenacanthus, with a prominent, undivided basolabial shelf and an almost straight orolingual ridge. [source] Age profiles of rhino fauna from the Middle Pleistocene Nanjing man site, south China,explained by the rhino specimens of living speciesINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 3 2001Haowen Tong Abstract A total of 60 pieces of rhino materials have been identified from the Nanjing Man site. Morphologically, they belong to the species Dicerorhinus mercki. Among the materials, 40 pieces are broken bones, and 20 are isolated teeth or jaw bones (totally comprising 41 tooth units). Among the teeth, 74% are deciduous, most of them attached to jaws. Other isolated teeth are not greatly worn, meaning they were not naturally replaced, so they represent juvenile animals. Because the skeletons are completely isolated and most of them are broken, their death can not be attributed to a natural trap. Therefore, it is very probable that hominid activities were associated with rhinos at this site. Copyright © 2001 John Wiley & Sons, Ltd. [source] The utility of tooth enamel microstructure in identifying isolated dinosaur teethLETHAIA, Issue 3 2010SUNNY H. HWANG Hwang, S.H. 2010: The utility of tooth enamel microstructure in identifying isolated dinosaur teeth. Lethaia, Vol. 43, pp. 307,322. The identification of isolated dinosaur teeth is frequently an uncertain process because dinosaur teeth are simple in morphology compared to those of mammals. Teeth among genera and species within major dinosaur clades are often identical, and damage or abrasion of teeth further complicates their identification. To aid diagnosis of isolated teeth, systematic descriptions of dinosaur teeth have been compiled, and quantitative morphometric identification methods have also been developed. However, these aids work best with relatively intact teeth. Enamel microstructure, in contrast, can be used to identify the minutest of tooth fragments as long as the entire enamel thickness, often <100 ,m, is preserved. In addition, enamel microstructure can be used to differentiate isolated teeth that are similar in morphology but have different enamel, such as ankylosaur and posterior pachycephalosaurid or basal theropod and tyrannosaurid teeth. To evaluate the efficacy of enamel microstructure as an identification tool, nine isolated dinosaur teeth, specimens originally identified as ,Carnosauria' indet., Theropoda indet., Nanotyrannus sp., Tyrannosauridae indet., Troodontidae indet., Pachycephalosauridae indet., Hadrosaurinae indet. and cf. Thescelosaurus sp., were sectioned and their enamel examined using scanning electron microscopy. Upon inspection of their enamel microstructure, three of the specimens could be identified to genus, and the taxonomic identity of all the specimens were better understood. While enamel microstructure may not always constrain the identity of an indeterminate tooth to the generic or species level, it usually allows for a more accurate identification. ,Dinosaur teeth, enamel microstructure, taxonomic identification, microfossils. [source] ADDITIONAL SPECIMENS OF SUDAMERICID (GONDWANATHERIA) MAMMALS FROM THE EARLY PALEOCENE OF ARGENTINAPALAEONTOLOGY, Issue 5 2008YAMILA GUROVICH Abstract:, The extinct, Cretaceous,Paleogene Gondwanatherians have previously been considered to be early xenarthrans, multituberculates and more recently Mammalia incertae sedis. However, the phylogenetic relationships of Gondwanatheria have yet to be resolved. In this paper, additional dental specimens of the gondwanatherian Sudamerica ameghinoi from the Early Paleocene Salamanca Formation of Argentina are described. These specimens provide additional information on Gondwanatheria affinities, sudamericid morphology and help support earlier hypotheses on Sudamerica dental formula and tooth categories. Sudamericid dental functional morphology and body mass estimates, based on measurements of isolated teeth, are inferred. Dental morphology such as hypsodonty, enamel microstructure and crown features do support a robust clade for Sudamericidae. [source] Brief communication: Identification reassessment of the isolated tooth Krapina D58 through occlusal fingerprint analysisAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2010Luca Fiorenza Abstract High variability in the dentition of Homo can create uncertainties in the correct identification of isolated teeth. For instance, standard tooth identification criteria cannot determine with absolute certainty if an isolated tooth is a second or third maxillary molar. In this contribution, using occlusal fingerprint analysis, we reassess the identification of Krapina D58 (Homo neanderthalensis), which is catalogued as a third maxillary molar. We have hypothesized that the presence/absence of the distal occlusal wear facets can be used to differentiate second from third maxillary molars. The results obtained confirm our hypothesis, showing a significant difference between second and third maxillary molars. In particular we note the complete absence of Facets 7 and 10 in all third molars included in this analysis. The presence of these facets in Krapina D58 eliminates the possibility that it is a third maxillary molar. Consequently it should be reclassified as a second molar. Although this method is limited by the degree of dental wear (i.e., unworn teeth cannot be analyzed) and to individual molars in full occlusion, it can be used for tooth identification when other common criteria are not sufficient to discriminate between second and third maxillary molars. Am J Phys Anthropol 143:306,312, 2010. © 2010 Wiley-Liss, Inc. [source] New hominid fossils from Woranso-Mille (Central Afar, Ethiopia) and taxonomy of early AustralopithecusAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2010Yohannes Haile-Selassie Abstract The phylogenetic relationship between Australopithecus anamensis and Australopithecus afarensis has been hypothesized as ancestor-descendant. However, the weakest part of this hypothesis has been the absence of fossil samples between 3.6 and 3.9 million years ago. Here we describe new fossil specimens from the Woranso-Mille site in Ethiopia that are directly relevant to this issue. They derive from sediments chronometrically dated to 3.57,3.8 million years ago. The new fossil specimens are largely isolated teeth, partial mandibles, and maxillae, and some postcranial fragments. However, they shed some light on the relationships between Au. anamensis and Au. afarensis. The dental morphology shows closer affinity with Au. anamensis from Allia Bay/Kanapoi (Kenya) and Asa Issie (Ethiopia) than with Au. afarensis from Hadar (Ethiopia). However, they are intermediate in dental and mandibular morphology between Au. anamensis and the older Au. afarensis material from Laetoli. The new fossils lend strong support to the hypothesized ancestor-descendant relationship between these two early Australopithecus species. The Woranso-Mille hominids cannot be unequivocally assigned to either taxon due to their dental morphological intermediacy. This could be an indication that the Kanapoi, Allia Bay, and Asa Issie Au. anamensis is the primitive form of Au. afarensis at Hadar with the Laetoli and Woranso-Mille populations sampling a mosaic of morphological features from both ends. It is particularly difficult to draw a line between Au. anamensis and Au. afarensis in light of the new discoveries from Woranso-Mille. The morphology provides no evidence that Au. afarensis and Au. anamensis represent distinct taxa. Am J Phys Anthropol 2010. © 2009 Wiley-Liss, Inc. [source] Brief communication: Identification reassessment of the isolated tooth Krapina D58 through occlusal fingerprint analysisAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2010Luca Fiorenza Abstract High variability in the dentition of Homo can create uncertainties in the correct identification of isolated teeth. For instance, standard tooth identification criteria cannot determine with absolute certainty if an isolated tooth is a second or third maxillary molar. In this contribution, using occlusal fingerprint analysis, we reassess the identification of Krapina D58 (Homo neanderthalensis), which is catalogued as a third maxillary molar. We have hypothesized that the presence/absence of the distal occlusal wear facets can be used to differentiate second from third maxillary molars. The results obtained confirm our hypothesis, showing a significant difference between second and third maxillary molars. In particular we note the complete absence of Facets 7 and 10 in all third molars included in this analysis. The presence of these facets in Krapina D58 eliminates the possibility that it is a third maxillary molar. Consequently it should be reclassified as a second molar. Although this method is limited by the degree of dental wear (i.e., unworn teeth cannot be analyzed) and to individual molars in full occlusion, it can be used for tooth identification when other common criteria are not sufficient to discriminate between second and third maxillary molars. Am J Phys Anthropol 143:306,312, 2010. © 2010 Wiley-Liss, Inc. [source] | |||||||||||||