DiceCT applied to fossilized hard tissues: A preliminary case study using a miocene bird

Abstract

Iodine-based contrasting agents for computed tomography (CT) have been used for decades in medicine. Agents like Lugol's iodine enhance the contrasts between soft tissues and mineralized (skeletal) tissues. Because a recent study on extant avian heads showed that iodine-ethanol (I 2 E) is a better contrast enhancer overall than the standard Lugol's iodine, here, we tested if I 2 E could also enhance the CT contrasts of two fossilized skeletal tissues: bone and calcified cartilage. For this, we used a partial ankle joint from an extinct pheasant from the Late Miocene of Northwest China (Linxia Basin). The pre-staining CT scans showed no microstructural details of the sample. After being immersed into a solution of 1% I 2 E for 8 days and scanned a second time, the contrasts were drastically enhanced between the mineralized tissues (bony trabeculae and calcified cartilage) and the sediments and minerals inside vascular spaces. After three other staining-scanning cycles in 2%, 3%, and 6% I 2 E solutions, the best contrasts were obtained after immersion in 6% I 2 E for 7 days. Energy Dispersive Spectroscopy showed that iodine was preferentially absorbed by the mineralized tissues and the minerals in the vascular spaces, but not by the sediments. This method not only effectively increased the contrasts of two different fossilized skeletal tissues, it was also non-destructive and reversible because part of the fossil was successfully de-stained after a few days in pure ethanol. These preliminary results indicate that iodine-ethanol has the potential to be used widely in vertebrate paleontology to improve CT imaging of fossilized tissues.

Editorial: Technological Frontiers in Dinosaur Science Mark a New Age of Opportunity for Early Career Researchers

“…In fact, young researchers are taking the lead in research with new scientific approaches (e.g. Falkingham et al, 2018;Lefebvre et al, 2020;Manafzadeh and Gatesy, 2020;Bailleul et al, 2021;Nieto et al, 2021;Serrano-Martínez et al, 2021;Van Bijlert et al, 2021;Ma et al, 2022;Wiemann et al, 2022). Young scientists are the key to bringing new perspectives into science and pushing technological and methodological developments.…”

Endless bones most beautiful: Book review of Vivian de Buffrénil, Armand J. de Ricqlès, Louise Zylberberg, Kevin Padian (eds) 2021 Vertebrate Skeletal Histology and Paleohistology

“…These sections are likely to age given constant new developments (e.g. Bailleul et al, 2021 on DiceCT applied to fossils), but they sure provide useful reminders and introductions to the power of such approaches. The volume is a combination of current, topical content with a rather classical thematic coverage and documentation of primary data.…”