Miocene ascidians from Bosnia and Herzegovina

The study uncovers the world’s most diverse collection of fossilized ascidian spicules, found in Bogutovo Selo near Ugljevik, Bosnia and Herzegovina, and dating back to the Middle Miocene. These ancient sea squirts share a closer resemblance to species from the distant Eocene epoch in Australia than to those from the Miocene Eastern Paratethys region. This finding suggests that a once-widespread group of ascidians persisted well into the Miocene within isolated refugia in the Mediterranean Sea.