Discoveries of new ants in Dominican amber and their role in unraveling patterns of local extinction

The island of Hispaniola harbors a rich fossil and extant ant fauna, comprising ~126 extant native species on the island and ~96 species preserved in geographically contiguous Dominican amber. Though amber from the Dominican Republic has been studied for decades, discoveries of new species preserved in this deposit continually shed light on patterns of faunal turnover or the change in species composition in a given community, and community structure in island systems through time. Here we describe four new species of the Basiceros genus group from Miocene-aged Dominican amber. Ants of the Basiceros genus group are elusive species known for their distinct setation and often weirdly shaped heads. Though their natural history is mostly a mystery and the phylogenetic relationships among species within the genus group remain unknown, one thing is known for sure; they are largely extinct on Hispaniola today, with only one extant representative. Using this novel case of local extinction on the island of Hispaniola, we assessed patterns in faunal turnover, looking to uncover what allows species to persist through time. The discovery of Basiceros genus group species - known leaflitter ants - in the fossil record provides us with further understanding of the Hispaniolan fossil ant community structure. Conversely, the apparent extinction of this group in modern-day Hispaniola could be evidence of contingent local extinctions and their role in shaping modern-day communities.