A surprise in amber: exotic harvestmen once lived in Europe

An international research team has discovered a previously unknown species of harvestman in amber dating back some 35 million years from Ukraine and the Baltic region, held in the collection of the Museum für Naturkunde Berlin. The new species demonstrates that a group of these arachnids, now extinct in Europe, was significantly more widespread during the Eocene than previously thought. The findings were published in the journal Acta Palaeontologica Polonica.

Amber fossils (inclusions) are considered a particular stroke of luck for research: trapped in tree resin millions of years ago, organisms can be preserved in them with exceptional detail. The Museum für Naturkunde Berlin’s amber collection contains numerous such objects of great scientific value. Among them are the two specimens that have now enabled the description of the new harvestman species Balticolasma wunderlichi. It belongs to the subfamily Ortholasmatinae – a group often characterised by a striking appearance, with a highly ornamented body surface and sometimes featuring lattice-like projections on the head. Fossil representatives of this group were previously unknown.

The new species was discovered and described by a German-Bulgarian team led by the palaeontologist Christian Bartel from the Bavarian State Collections of Natural History and Plamen Mitov from Sofia University. To investigate the three-dimensional anatomy, the researchers used high-resolution X-ray methods. Computed tomography scans at the Helmholtz Centre Hereon at DESY in Hamburg revealed even the finest structures – including a net-like pattern of fine ridges covering the upper surface of the body, as well as complexly structured mouthparts.

Co-author Jason Dunlop from the Museum für Naturkunde Berlin places the find in a broader context: “Baltic amber is known for its enormous diversity of fossils and repeatedly reveals species that no longer occur in Europe today. The fact that the new harvestman species was also found in Ukraine shows how similar the faunas of both regions were at that time.”

The discovery of an ortholasmatine harvestman in European amber deposits was surprising, as harvestmen of this group no longer exist in Europe today. Related species currently live in East Asia as well as in North and Central America. Apparently, these animals were much more widespread in the Northern Hemisphere 35 million years ago than they are today.

With this new discovery, our understanding of fossil harvestman diversity continues to grow: a total of 19 species are now known from Baltic amber and seven from Ukrainian Rovno amber – six of which occur in both regions. The new evidence thus provides important insights into how animal groups spread and evolve over geological time.

Bartel, C., Mitov, P. G., Dunlop, J. A. & Hammel, J. U. 2026. 3D analyses of the first ortholasmatine harvestmen from European Eocene ambers. Acta Palaeontologica Polonica, 71, 95–107. https://www.app.pan.pl/archive/published/app71/app012832025.pdf