European Palaeobotany and Palynology Conference 2026

Late Eocene Baltic amber represents the largest amber deposit worldwide. It has been studied for centuries, but plant inclusions are comparatively scarce and the angiosperm diversity of the Baltic amber source area is still insufficiently understood for a holistic reconstruction of the amber forest. Here we describe three well-preserved flowers analyzed with high-resolution X-ray tomography (µCT) and synchrotron radiation-based micro-computed tomography (SRµCT). These non-invasive methods make it possible to visualize morphological details that are not visible using just light microscopy. Two fossils comprise a corolla and diplostemenous androecium forming a distinct shallow floral ring. They share long ribbon-like antepetalous staminodia and fertile alternipetalous stamens with a distinctive H-valvate anther dehiscence and elongated connective extensions. The third fossil consists only of the androecium. Using the morphological analyses complemented by phylogenetic approaches, the fossils were retrieved within the Hamamelidaceae (Hamamelidoideae, Saxifragales) and may represent a morphological intermediate between the Late Creataceous Androdecidua endressii Magallón, Herendeen et Crane and flower morphologies of extant members of the family. Our fossils are the first unequivocal Baltic amber record of the family, they also increase the known floral diversity of the family and add to their sparse fossil record of well-preserved flowers.