关键词: 缅甸琥珀, 化石, 昆虫琥珀, 三维重建, 显微CT, X射线, 古生物学

Abstract: 【Aim】 Burmese ambers from the Hukawng Valley of North Myanmar are estimated to be formed in the middle Cretaceous. Not only did these ambers have very high artistic value, but also their inclusions had high biodiversity and immeasurable scientific value. Micro-CT can provide high-resolution tomographic image of internal anatomy from fossil (amber). In this case, Micro-CT is becoming one of the common methods of amber study. However, the biological structures within the amber visible from microscopy may demonstrate very different results under X-rays. On the contrary, the extant materials provide similar performance in the detection under microscopy and Micro-CT. This study aims to ascertain this particular phenomenon based on nine Burmese amber samples from the Hukawang Valley. 【Methods】 Photographs were taken using a Nikon 5200D digital camera and processed with Helicon Focus 5.3 software. Nine Burmese amber samples were scanned by micro-CT. The Burmese amber inclusions were reconstructed by computer tomography reconstruction technologys.【Results】 The Micro-CT results were mainly divided into three types: no contrast completely, contrast in partial structure and good contrast in most structures. The external and internal structures with visible contrast were reconstructed based on the CT data obtained from Burmese ambers. 【Conclusion】 There is not always good relationship between visible light imaging and X-ray imaging of amber inclusions. This phenomenon is probably related to the preservation of the amber, amber density difference, and the difference in contrast between the surroundings of amber. The physical and chemical changes during the process of amber formation and burial are very complex. The mechanisms would be more complex and difficult to be inferred. Here we preliminarily illustrated the main types of this phenomenon. More comprehensive sampling and more strict experimental design in the follow-up studies may finally solve this problem on taphonomy.

Key words: Burmese amber, fossil, amber insect, three dimensional reconstruction, micro-CT, X-ray, paleontology