Find research datasets worth reusing

opencc-by-4.0Dec 2004View details →

Figure 13. Comparison between Trinomys upper teeth, which presents a in Relationships among extant and fossil echimyids (Rodentia: Hystricognathi)

Figure 13. Comparison between Trinomys upper teeth, which presents a deep sulcus between protoloph and the protocone region in little-worn teeth (indicated by an arrow in the dP4), resulting in a hypoflexus continuous to the paraflexus ('deep main fold' of Moojen, 1948), and Proechimys upper teeth, which do not present a sulcus or have it quite shallow (character 32). A, Trinomys dimidiatus (MN 4016, left series); B, Proechimys gularis (AMNH 67323, right series reversed to the left side). The arrows, in the dP4 of both specimens, show the area between the protoloph and the protocone region. Note that, although the Trinomys specimen is older (has all teeth already worn), the sulcus is present in all teeth; by contrast, in Proechimys, only the unworn M3 presents the sulcus, which is already absent in dP4–M2.

opencc-by-4.0Jun 2008View details →

Figure 11. Length versus posterior width for Lake Callabonna Diprotodon lower molar teeth. A, M1. B, M2. C, M3. D, M4 in Taxonomy and palaeobiology of the largest-ever marsupial, Diprotodon Owen, 1838 (Diprotodontidae, Marsupialia)

Figure 11. Length versus posterior width for Lake Callabonna Diprotodon lower molar teeth. A, M1. B, M2. C, M3. D, M4.

opencc-by-4.0Jun 2008View details →

Figure 10. Length versus posterior width for Darling Downs Diprotodon lower molar teeth. A, M1. B, M2. C, M3. D, M4 in Taxonomy and palaeobiology of the largest-ever marsupial, Diprotodon Owen, 1838 (Diprotodontidae, Marsupialia)

Figure 10. Length versus posterior width for Darling Downs Diprotodon lower molar teeth. A, M1. B, M2. C, M3. D, M4.

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Ecological signal in the size and shape of marine amniote teeth – 3D models and landmarks

Amniotes have been a major component of marine trophic chains from the beginning of the Triassic to present day, with hundreds of species. However, inferences of their (palaeo)ecology have mostly been qualitative, making it difficult to track how dietary niches have changed through time and across clades. Here, we tackle this issue by applying a novel geometric morphometric protocol to 3D models of tooth crowns across a wide range of raptorial marine amniotes. Our results highlight the phenomenon of dental simplification and widespread convergence in marine amniotes, implying strong functional constraints which limit the range of tooth crown morphologies. Importantly, we quantitatively demonstrate that tooth crown form (shape plus size) is strongly associated with diet, whereas crown surface complexity is not. The maximal range of tooth shapes in both mammals and reptiles is seen in medium-sized taxa; large crowns are simple and restricted to a fraction of the morphospace. We recognise four principle raptorial guilds within toothed marine amniotes (durophages, generalists, meat cutters, and flesh piercers). Moreover, even though all these feeding guilds have been convergently colonised over the last 200 million years, a series of dental morphologies are unique to the Mesozoic period, probably reflecting a distinct ecosystem structure.

opencc-zeroDec 2022View details →

dryad40/100

Armed to the teeth: Supplementary material, R code, Rdata, mesh, landmarks

The structure, composition, and shape of teeth have been related to dietary specialization in many vertebrate species, but comparative studies on snakes' teeth are lacking. Yet, snakes have diverse dietary habits that may impact the shape of their teeth. We hypothesize that prey properties, such as hardness and shape, as well as feeding behavior, such as aquatic or arboreal predation, or holding vigorous prey, impose constraints on the evolution of tooth shape in snakes. We compared the morphology of the dentary teeth of 63 species that cover the phylogenetic and dietary diversity of snakes, using 3D geometric morphometrics and linear measurements. Our results show that prey hardness, foraging substrate, and the main foraging mechanical challenge are important drivers of tooth shape, size, and curvature. Overall, long, slender, curved teeth with a thin layer of hard tissue are observed in species that need to maintain a grip on their prey. Short, stout, less curved teeth are associated with species that undergo high or repeated loads. Our study demonstrates the diversity of tooth morphology in snakes and the need to investigate its underlying functional implications to better understand the evolution of teeth in vertebrates.

opencc-zeroMar 2023View details →

Fig. 16 in Bumblebees with big teeth: revising the subgenus Alpigenobombus with the good, the bad and the ugly of numts (Hymenoptera: Apidae)

Fig. 16. BEAST estimate of species' dated phylogeny as an ultrametric tree (outgroup B. festivus Smith, 1861, not shown) from six genes for the subgenus Alpigenobombus Skorikov, 1914. All nodes have support values> 0.98. Numbers at nodes are estimates of the age of a node in Ma before the present, with grey node bars representing the 95% highest posterior density interval of the age estimates.

Figs 1‒9 in Bumblebees with big teeth: revising the subgenus Alpigenobombus with the good, the bad and the ugly of numts (Hymenoptera: Apidae)

Figs 1‒9. Individuals of the subgenus Alpigenobombus Skorikov, 1914 (with photo credits). 1. Bombus mastrucatus Gerstaecker, 1869, worker Norway robbing (P. Haringsma). 2. B. kashmirensis Friese, 1909 s. str., worker China-Sichuan robbing (PW). 3. B. kashmirensis (taxon meinertzhageni Richards, 1928) worker India-Kashmir-Zanskar (PW). 4. B. sikkimi Friese, 1918, worker India-Arunachal (MS). 5. B. nobilis Friese, 1905 s. str., worker China-Yunnan (ZR). 6. B. genalis Friese, 1918, worker India-Arunachal (MS). 7. B. breviceps Smith, 1852 (taxon dentatus Handlirsch, 1888) worker ChinaYunnan (PW). 8. B. breviceps (taxon channicus Gribodo, 1892) worker Thailand (CT). 9. B. grahami (Frison, 1933) worker India-Arunachal (MS). Some images reversed.

Figs 106–115 in Bumblebees with big teeth: revising the subgenus Alpigenobombus with the good, the bad and the ugly of numts (Hymenoptera: Apidae)

Figs 106–115. Morphology of the male genitalia for species of the subgenus Alpigenobombus Skorikov, 1914, from the dorsal aspect, anterior at the bottom of the image, posterior at the top. 106. Bombus wurflenii Radoszkowski, 1860, Turkey. 107. B mastrucatus Gerstaecker, 1869, Austria. 108. B. kashmirensis Friese, 1909, India-Kashmir. 109. B. rainai Williams, 2022, India-Kashmir. 110. B. sikkimi Friese, 1918, Nepal. 111. B. nobilis Friese, 1905, China-Sichuan. 112. B. validus Friese, 1905, China-Gansu. 113. B. genalis Friese, 1918, China-Yunnan. 114. B. breviceps Smith, 1852, ChinaSichuan. 115. B. grahami (Frison, 1933) China-Sichuan (left penis-valve recurved hook missing). Scale bars = 1 mm.

Figs 13–15 in Bumblebees with big teeth: revising the subgenus Alpigenobombus with the good, the bad and the ugly of numts (Hymenoptera: Apidae)

Figs 13–15. Distribution of the barcoded samples (and matching haplotypes) of the subgenus Alpigenobombus Skorikov, 1914, from Fig. 10 with their interpretation as the 11 species from Fig. 12 and from the associated morphology in the keys, shown as differently coloured spots as in the colour keys on the left, to indicate the approximate relative range extent among the species. 13. The wurflenii- group and kashmirensis-group. 14. The nobilis-group. 15. The breviceps-group. Relief map with hill shading, Cartesian orthonormal projection, the international boundaries shown as narrow grey lines. Images created in ArcGIS using World_Shaded_Relief basemap which is Copyright: ©2014 Esri.

Fig. 17. Diagram representing a in Bumblebees with big teeth: revising the subgenus Alpigenobombus with the good, the bad and the ugly of numts (Hymenoptera: Apidae)

Fig. 17. Diagram representing a corridor-dispersal model, encompassing a set of short-distance dispersal events permitted (in either direction) between the proposed areas of endemism, based on unique taxa, the geographical proximity of these areas, and the likely disposition of corridors with suitable habitat and favourable climates in the past.

Fig. 12 in Bumblebees with big teeth: revising the subgenus Alpigenobombus with the good, the bad and the ugly of numts (Hymenoptera: Apidae)

Fig. 12. Interpretation of filtered MrBayes estimate of phylogeny as a metric tree (outgroup B. festivus Smith, 1861, not shown) for the subgenus Alpigenobombus Skorikov, 1914, from COI-like sequences from the sequences identified in black and orange in Fig. 11 together with Bayesian Poisson-tree-process (PTP) models re-applied for assessing support for species' gene coalescents by maximum likelihood (for the 11 most likely candidate species). The scale bar is calibrated in substitutions per nucleotide site. Sequence labels and branch colours as in Fig. 10. Numbers above nodes are the Bayesian support values that all daughter haplotypes are parts of a single species. Grey spots show likely mitochondrial-to-nuclear transfers of the low-divergence numts accepted for estimating this tree. Asterisks mark sequences used as informal proxies for the type specimens of each of the taxon names in Table 2. To the right in grey are shown the interpretations of the PTP results as candidate species using the oldest available names for the species.

Figs 19–105 in Bumblebees with big teeth: revising the subgenus Alpigenobombus with the good, the bad and the ugly of numts (Hymenoptera: Apidae)

Figs 19–105 (see pages 28–29). Simplified diagrams for the colour patterns of the hair on the dorsum for particular female (f) and male (m) specimens of the species from Fig. 12. The dorsum is divided into regions, each of which shows only the predominant or most apparent colour for that region, using a simplified colour palette, with olive indicating a mixture of black and yellow hair, and grey indicating a mixture of black and white hair.

opencc-by-4.0Jul 2017View details →

Figure 3. – Lepisosteus platostomus. Left jaw. A in Histological characteristics of lower jaw bones and oral teeth of the short nose gar, Lepisosteus platostomus Rafinesque, 1820 (Lepisosteidae)

Figure 3. – Lepisosteus platostomus. Left jaw. A: Axial section of a caniniform tooth showing the apical cap of acrodin (ac) above the dentine cone (de), the collar enamel (en) that covers the tooth shaft, the dentine folds in the pulp cavity (pc), and the coronoid bone (cb). Scale bar = 500 μm. B: Detail of the apex of the tooth showing the odontoblastic canaliculi (arrow). Scale bar = 20 μm. C: Transverse section of a caniniform tooth showing the external ridges (arrows) and the dentine folds (arrowheads) in the pulp cavity (pc). The dentine is overlain by a thin collar enamel (en) covering the tooth shaft and participating in the folds. Scale bar = 100 μm. D: The section crosses through three small lingual teeth that show minute folds in their pulp cavity. A caniniform tooth can be seen at the bottom left. Scale bar = 50 μm.

opencc-by-4.0Jul 2017View details →

Figure 2. – Lepisosteus platostomus. A in Histological characteristics of lower jaw bones and oral teeth of the short nose gar, Lepisosteus platostomus Rafinesque, 1820 (Lepisosteidae)

Figure 2. – Lepisosteus platostomus. A: External view of the left lower jaw showing the caniniform teeth on the labial side of the jaw. The largest tooth (arrow) is located at the anterior tip of the jaw. On the lingual side of the jaw there are small sharp teeth (arrowheads). Scale bar = 5 mm. In the inset a detail of a caniniform tooth showing the external ridges at its base (arrowhead). Scale bar = 1 mm. B-D: Right jaw. B: Cross section of the jaw (microradiograph) showing five small teeth inserted on a coronoid bone (upper left) plus a larger tooth on the dentary. The white asterisk indicates the unmineralized Meckel's cartilage on the left hand side of the dentary (de). Scale bar = 2.5 mm. In the inset a microradiograph of a caniniform tooth and its attachment bone (bo), also showing its dentine core (arrowhead) with the apical acrodin cap (arrow). C: Parasagittal median section of the jaw (microradiograph) showing five caniniform teeth. The dentine folds occupy the total height of the pulp cavities. On the left one can also see five hypermineralized acrodin caps. Scale bar = 2 mm. D: Parasagittal lingual section of the jaw (microradiograph) showing the small lingual teeth series some of them showing minute mineralized folds in the pulp cavity. Scale bar = 1 mm.

Figure 5 in Histological study of the jaw teeth in the Devonian actinopterygian †Cheirolepis canadensis (Whiteaves)

Figure 5. – Details (ground sections) of the vascularized bone in the jaw of †Cheirolepis canadensis. A. Several areas of the jaw show layers of vascularized bone with osteocyte lacunae. Scale bar = 50 μm. B: Detail of bony tissue with a secondary osteon (black asterisk). The white arrows point to osteocyte lacunae and arrowheads point to a cementing line between primary bone (pb) and the secondary osteon. Scale bar = 20 μm. C: Detail of bony tissue showing the spindle-shaped osteocytic lacunae. Scale bar = 25 μm. Inset: detail of an osteocyte lacuna with its ramified cytoplasmic canaliculi. Scale bar = 10 μm.

Figure 5 in Comparative histology of caniniform teeth in some predatory ichthyophagous teleosts

Figure 5. – Dissostichus eleginoïdes (Nototheneidae). A: Virtual model of the whole left premaxilla (pmx) showing the external aspect of the three caniniform teeth with external basal ridges (arrowheads); a fourth broken tooth shows folds in the pulpar cavity (white arrows); B: Virtual cross-section showing dentine folds (white arrows) and external ridges (white arrowheads); the dentine (de) core of the tooth is perforated; C: Virtual axial section of the largest tooth showing thin cavity and canals in the dentine (de); the tooth is covered with a thin enameloid (en) layer and forms a cap at the apex of the tooth; white arrowheads point to fold in the pulpar cavity (pc); D, E: Detail of a longitudinal (D) and transverse (E) sections (MNHN-Histos 2344 (D), MNHN-Histos 2342 (E) in natural transmitted light) showing the presence of many vascular canals anastomosed (white arrows); no odontoblastic tubules is present; the tooth is covered with a thin enameloid layer (en). Scale bars: A = 5 mm; B = 2 mm; C = 1 mm; D = 10 μm; E = 40 μm.

Figure 4 in Comparative histology of caniniform teeth in some predatory ichthyophagous teleosts

Figure 4. – Sphyraena guachancho (Sphyraenidae). A: 3-D reconstruction of the premaxilla (pmx) with a virtual axial section of a caniniform tooth showing vascularized dentine (de) covered with a thin enameloid layer and a cap of enameloid (en); B: Longitudinal section (MNHN-Histos 2332 in polarized light) showing the spatial organization of collagen fibers that follow a trajectory parallel to the direction of the vascular canals and to the main axis of the tooth (black arrowheads); the tooth is covered with a thin enameloid (en) layer; C: Detail of the longitudinal section in B (MNHN-Histos 2332 in polarized light) showing the presence of odontoblastic canaliculi perpendicular to the tooth area (black arrowheads); the tooth is covered with a thin enameloid layer (en). Scale bars: A = 5 mm; B = 10 μm; C = 40 μm.

Figure 2 in Comparative histology of caniniform teeth in some predatory ichthyophagous teleosts

Figure 2. – Lepidopus caudatus (Trichiuridae). A: 3-D reconstruction of the premaxilla (pmx) with a virtual axial section of a caniniform tooth showing vascularized dentine (de) covered with a thin enameloid layer; B: Virtual cross section of the tooth caniniform in A having many denteones; C: Detail of a cross section (MNHNHistos 2347 in natural transmitted light) showing the presence of denteones (asterisks) and anastomosed vascular canals (arrowheads). Odontoblastic canaliculi (oc) take an orientation perpendicular to the axis of the tooth as it approaches the outer surface of the tooth. Scale bars: A = 5 mm; B = 2 mm; C = 50 μm.

Figure 1 in Some histological data of bone and teeth in the Rift Eelpout, Thermarces cerberus (Zoarcidae)

Figure 1. – Thermarces cerberus. Horizontal section (transmitted polarized light) of the lower left jaw showing numerous teeth sections aligned on two rows. The arrowhead points to the tooth detailed in figures 2, 3, 4. Scale bar = 500 µm. Figures 2, 3, 4. – Thermarces cerberus. Left lower jaw. Detail of a cross section of a tooth (see arrowhead in Fig. 1), natural transmitted light, polarized light and microradiography, respectively. The arrowhead points to the superficial hypermineralized layer of enameloid (Fig. 4). De: dentine; pc: pulp cavity. Scale bar = 100 µm. Figure 5. – Thermarces cerberus. Transversal section of the right lower jaw showing an axial section of a tooth. The tooth is fixed on the vascularized supporting bone (sb) by an unmineralized ligament (li). The dentine core is surrounded by a thin hypermineralized enameloid layer well seen at the tip of the tooth (en). At the base of the tooth, on the right, there is a tooth bud (arrowhead) in a lateral alveola of the dentary. Mc: Meckel cartilage. Scale bar = 250 µm. Figure 6. – Thermarces cerberus. Detail of a sagittal section of a vertebra. A: Polarized light; B: Microradiography. Note the fibrillary component of the vertebral bone (arrowhead). The mineralization of the vertebral bone is heterogeneous, and three weakly hypermineralized growth zones are seen (arrows). Scale bar = 100 µm.

Figure 4 in Histological study of the jaw teeth in the Devonian actinopterygian †Cheirolepis canadensis (Whiteaves)

Figure 4. – Virtual section (3D-tomography) through the long axis of the jaw of †Cheirolepis canadensis (sub-sample c; see Fig. 1A for location) showing for each tooth the dentine walls, the acrodine cap (white arrows) and the pulp cavity (*). Scale bar = 500 μm.