View of the excavation of the bow area of the Ilovik-Paržine 1 shipwreck. In the foreground, the cargo of logs and amphoras can be seen. Archaeologists are working near the structure of the bow complex. Adriboats © L. Damelet, CNRS/CCJ Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent six days a week. About 2,200 years ago, a Roman Republic ship sank off the coast of modern-day Croatia, with wood and amphorae (ancient storage containers) of wine on board. Scientists are not sure why it sank, but the Ilovik–Paržine 1 shipwreck was discovered in 2016. However, the archeologists and researchers behind a new study published today in the journal Frontiers in Materials weren’t interested in its precious cargo. The ship’s critical waterproofing layer was their treasure.  This unique protective layer on a ship traps pollen in its stickiness just like tree sap .…