1,721,009 research outputs found
Growth Rate Biometric Quantification by X-ray Microtomography on Larger Benthic Foraminifera: Three-dimensional Measurements Push Nummulitids into the Fourth Dimension
No full textThis work demonstrates the potential of three-dimensional biometric quantification using microtomography on larger benthic foraminifera. We compare traditional linear and area measures used for calculating three-dimensional characters with actual 3D measurements made from volume images obtained using X-ray microtomography (microCT). Two specimens of recent larger benthic foraminifera, i.e., Palaeonummulites venosus and Operculina ammonoides, were imaged with a high-resolution microCT scanner. This method enables three-dimensional imaging and calculation of measurements like 3D distances, surfaces and volumes. The quantitative high-resolution images enabled the extraction of the lumina from the proloculus to the last complete scanned chamber and of the canal system spreading into marginal chord and septa. External surfaces and volumes were calculated on the extracted parts. These measurements allowed the calculation of porosity and microporosity to obtain the test density, which is the basis for many inferences about foraminifera, e.g., reconstructions of transport and deposition. Volume and surface measurements of the proloculus allow the calculation of sphericity deviation, which is useful for determining evolutionary trends in species based on individuals resulting from asexual reproduction (A forms). The three-dimensional data presented here show the actual growth of the foraminiferal cell and the development of the test. Measurements made on an equatorial section cannot be considered representative of a three-dimensional test, unless a correspondence between 2D data with 3D data shows significant correlation. Chamber height, septal distance, spiral growth and chamber area were measured on the equatorial section and correlated with the volume measurements from 3D images to determine the predictive value of the 1D and 2D measures for estimating the 3D morphological parameters. In particular, we show that the equatorial section area of chambers correlates significantly with the chamber volume and can be used to differentiate between nummulitid genera according to their different growth patterns. ©TÃBÄ°TAK
Fig. 2 in Micro-computed tomography for natural history specimens: a handbook of best practice protocols
No full textFig. 2. Schematic overview of the X-Ray generator.Published as part of Keklikoglou, Kleoniki, Faulwetter, Sarah, Chatzinikolaou, Eva, Wils, Patricia, Brecko, Jonathan, Kvaček, Jiří, Metscher, Brian & Arvanitidis, Christos, 2019, Micro-computed tomography for natural history specimens: a handbook of best practice protocols, pp. 1-55 in European Journal of Taxonomy 522 on page 4, DOI: 10.5852/ejt.2019.522, http://zenodo.org/record/265654
Fig. 3 in Micro-computed tomography for natural history specimens: a handbook of best practice protocols
No full textFig. 3. The spectrum generated by an X-ray generator at 100kV with and without filtering. Image generated by the simulation environment https://www.oem-xray-components.siemens.com/x-ray-spectra-simulation.Published as part of Keklikoglou, Kleoniki, Faulwetter, Sarah, Chatzinikolaou, Eva, Wils, Patricia, Brecko, Jonathan, Kvaček, Jiří, Metscher, Brian & Arvanitidis, Christos, 2019, Micro-computed tomography for natural history specimens: a handbook of best practice protocols, pp. 1-55 in European Journal of Taxonomy 522 on page 5, DOI: 10.5852/ejt.2019.522, http://zenodo.org/record/265654
Fig. 5 in Micro-computed tomography for natural history specimens: a handbook of best practice protocols
No full textFig. 5. Schematic overview of the reconstruction procedure. Image by HCMR micro-CT lab.Published as part of Keklikoglou, Kleoniki, Faulwetter, Sarah, Chatzinikolaou, Eva, Wils, Patricia, Brecko, Jonathan, Kvaček, Jiří, Metscher, Brian & Arvanitidis, Christos, 2019, Micro-computed tomography for natural history specimens: a handbook of best practice protocols, pp. 1-55 in European Journal of Taxonomy 522 on page 7, DOI: 10.5852/ejt.2019.522, http://zenodo.org/record/265654
Fig. 6. Data processing from a in Micro-computed tomography for natural history specimens: a handbook of best practice protocols
No full textFig. 6. Data processing from a stack of 2D images to a 3D model. Image by MNHN.Published as part of Keklikoglou, Kleoniki, Faulwetter, Sarah, Chatzinikolaou, Eva, Wils, Patricia, Brecko, Jonathan, Kvaček, Jiří, Metscher, Brian & Arvanitidis, Christos, 2019, Micro-computed tomography for natural history specimens: a handbook of best practice protocols, pp. 1-55 in European Journal of Taxonomy 522 on page 7, DOI: 10.5852/ejt.2019.522, http://zenodo.org/record/265654
Fig. 4 in Micro-computed tomography for natural history specimens: a handbook of best practice protocols
No full textFig. 4. Example of the projection images resulting from the scanning process. Image by HCMR micro- CT lab.Published as part of Keklikoglou, Kleoniki, Faulwetter, Sarah, Chatzinikolaou, Eva, Wils, Patricia, Brecko, Jonathan, Kvaček, Jiří, Metscher, Brian & Arvanitidis, Christos, 2019, Micro-computed tomography for natural history specimens: a handbook of best practice protocols, pp. 1-55 in European Journal of Taxonomy 522 on page 6, DOI: 10.5852/ejt.2019.522, http://zenodo.org/record/265654
FIGURE 4 in Wallaceochromis gen. nov, a new chromidotilapiine cichlid genus (Pisces: Perciformes) from West Africa
No full textFIGURE 4. Consensus BI tree (50% majority rule) of chromidotilapiines, based on six genes, taken from Schwarzer et al. (2014), modified. The dataset comprises mitochondrial and nuclear sequences of six independent markers. Green numbers at nodes refer to bootstrap values (BS, 1,000 replicates) of the ML run and black numbers to Bayesian posterior probabilities (BPP). Red circles represent a 100% BS support and 1.00 BPP and black circles 1.00 BPP and lower BS values. The leaf stability index exceeded 0.93 for all specimens. For more details, see Schwarzer et al., (2014, fig.4).Published as part of Lamboj, Anton, Trummer, Franziska & Metscher, Brian D., 2016, Wallaceochromis gen. nov, a new chromidotilapiine cichlid genus (Pisces: Perciformes) from West Africa, pp. 124-130 in Zootaxa 4144 (1) on page 128, DOI: 10.11646/zootaxa.4144.1.8, http://zenodo.org/record/25831
Fig. 10. Measuring the maximum width W in Micro-computed tomography for natural history specimens: a handbook of best practice protocols
No full textFig. 10. Measuring the maximum width W (in pixels) of the projected specimen (as the distance from the rotation axis - dotted line - to the farthest end of the sample) to calculate the number of radiographs needed. This measurement is done for the angular position of the rotating platform where the projected specimen is the widest. For a complete rotation, the projected specimen would stay within the limits of the rectangle. Photo by MNHN.Published as part of Keklikoglou, Kleoniki, Faulwetter, Sarah, Chatzinikolaou, Eva, Wils, Patricia, Brecko, Jonathan, Kvaček, Jiří, Metscher, Brian & Arvanitidis, Christos, 2019, Micro-computed tomography for natural history specimens: a handbook of best practice protocols, pp. 1-55 in European Journal of Taxonomy 522 on page 17, DOI: 10.5852/ejt.2019.522, http://zenodo.org/record/265654
Wallaceochromis Lamboj, Trummer & Metscher 2016, gen. nov.
No full textWallaceochromis gen. nov. Differential Diagnosis. Lachrymal with four openings of laterosensory system; small chest scales; sixteen scales around caudal peduncle; upper lateral line clearly separated from dorsal fin base; teeth in both jaws unicuspid, a few teeth situated anterolaterally in the lower jaws with a curvature of the crown directed posteriorly and not buccally; no microbranchiospines; gill rakers on the outer row of the first ceratobranchial pachydermatous, transversely aligned, with a tuberculate and concave upper surface and a protracted distal tip; sexual dimorphism well developed: Males usually one third larger than females; in males first pelvic fin ray always longest, in females second (sometimes second and third) pelvic fin ray longer than first, giving the distal tip of the fin a rounded rather than pointed appearance. Snout pointed; dorsal head profile straight and sloping; low supraoccipital crest; ethmovomerine skull region slightly elongate and sloping at a low angle; it differs from Pelvicachromis in two contiguous tubular infraorbital bones (vs. three, with gap between 2nd and 3rd); 26–27 vertebrae with a tendency to higher abdominal vertebral counts (14–15 vs. 13–14); a more narrow interorbital region in adult specimens (maximum of 21.7–25.6% HL vs. 26.8–36.7% HL); seven or eight vertical dark bars on body, visible in several behavioral situations (vs. no such bars). Included species: Wallaceochromis humilis (Boulenger, 1916); type species (fig. 2, 3A,B) Wallaceochromis rubrolabiatus (Lamboj, 2004) (fig. 3C,D) Wallaceochromis signatus (Lamboj, 2004) (fig. 3E,F) Etymology. In honor of Alfred R. Wallace, co-founder of the theory of evolution and founder of biogeography; chromis, a common ending for African cichlids. Distribution. The genus is restricted to Guinea, Sierra Leone, and western parts of Liberia, where it occurs strictly in freshwater (Lamboj, 2004a). Wallaceochromis rubrolabiatus and W. signatus are only known from the Kolente River basin in Guinea, while W. humilis is found in the whole distribution area of the genus, including the Kolente River basin.Published as part of Lamboj, Anton, Trummer, Franziska & Metscher, Brian D., 2016, Wallaceochromis gen. nov, a new chromidotilapiine cichlid genus (Pisces: Perciformes) from West Africa, pp. 124-130 in Zootaxa 4144 (1) on pages 126-127, DOI: 10.11646/zootaxa.4144.1.8, http://zenodo.org/record/25831
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