High throughput micro-CT scanning of small fossils: preparation, packing, parameters and post-processing

Abstract

High-resolution X-ray microcomputed tomography, or microCT (CT), enables the digital imaging of whole objects in three dimensions. The power of CT to visualise internal features without disarticulation makes it particularly valuable for the study of museum collections, which house millions of physical specimens documenting the spatio-temporal patterns of life. Despite its potential for comparative analyses, most CT studies include limited numbers of museum specimens, due to the challenges of digitising numerous individuals within a project scope. Here we describe a method for high-throughput CT scanning of hundreds of small (< 2 cm) specimens in a single container, followed by individual labelling and archival storage. We also explore the effects of various packing materials and multiple specimens per capsule to minimize sample movement that can degrade image quality, and hence CT investment. We demonstrate this protocol on vertebrate fossils from Queensland Museum, Australia, as part of an effort to track community responses to climate change over evolutionary time. This system can be easily modified for other types of wet and dry material amenable to X-ray attenuation, including geological, botanical and zoological samples, providing greater access to large-scale phenotypic data and adding value to global collections.