SCIENCE
paleontology
Micro-computed tomography reveal a new kind of tooth replacement in vertebrates The internal structure of fossils can be explored through the non-
destructive technique of X-ray micro-computed tomography (μCT). Tissues of different densities (e.g. bone, tooth enamel, tooth dentine) or cavities left by nerves or blood vessels are translated into different levels of gray on the computer, which allows the paleontologist to select (“segment”) similar tissues through all the sections of a 3D object. The segmented specimen can then be visualized as a 3D model and the scientist can “navigate” through it, rotating the object, hiding certain tissues or cutting off the fossil at a given point to see its internal structure in section. A recent study on a prehistoric fish made some discoveries new to science. A contributor to the study, Lea Léuzinger, shares more about the techniques used and the findings here.
Above: Fig. 1) Photograph of a lower hemimandible of the Jurassic bony fish Scheenstia sp. (MJSN TCH005-353) uncovered by the Paléontologie A16 team in the Swiss Jura. Lingual view. Source: Figure derives from open-access publication LEUZINGER, L., CAVIN, L., LÓPEZ-ARBARELLO, A. and BILLON-BRUYAT, J.-P. 2019. Peculiar tooth renewal in a Jurassic ray-finned fish (Lepisosteiformes, Scheenstia sp.). Palaeontology, 1–13. Creative Commons license applies. © NatureVolve digital magazine. All rights reserved.
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