Micro-CT of fossils preserved in amber

X-ray micro-CT is gaining importance among paleontologists for studying fossil remains. In micro-CT, a 3D representation of the specimen is calculated from a series of X-ray transmission images recorded from different angles. It is a non-destructive technique that requires little or no sample preparation. Micro-CT proves to be especially suited for studying fossil inclusions in amber, the fossilized resin of trees. Yet only few applications have been described in literature. A number of specimens were therefore scanned at the new ultra-high-resolution tomography facility of the Ghent University (Belgium). This facility offers spatial resolutions down to the micrometer level. We show that a wealth of taxonomical detail can be preserved in amber, often enough for a detailed description and classification down to a species level, even for specimens smaller than 1 mm. Micro-CT can also reveal features that are invisible using the standard optical techniques due to for example, air bubbles, other inclusions or opacity of the amber itself. Even internal structures inside the specimen can be revealed. This implies that micro-CT can become an important tool for paleontologists.