Some literature. Some types also spelt Kossura. Modern Panterellia.
I want to learn more!!!
Alföldy, Géza. “Ein römischer Ritter aus Cossura (Pantelleria).” Zeitschrift für Papyrologie und Epigraphik, no. 151 (2005): 193-213.
APh has about 25 more relevant records but one must search Pantelleria to find them.
Also think about in light of coins of Melita (Malta), e.g.
CHECK OUT THE SPECIMENS IN BERLIN!! Go here. Then enter Cossura as your search term. Also this twitter thread.