The son of a government official in Messina, Sicily, Scilla studied under Andrea Sacchi in Rome and became a painter. He began to study fossils found in the hills of Sicily, sometimes accompanied by botanist Paolo Boccone. Scilla's only written scientific work is La vana speculazione disingannata dal senso ("Vain Speculation Undeceived by Sense", 1670). In this work he argues for a scientific explanation for fossils, as opposed to them being of fantastic origin or a test of faith from God. He also correctly identified the supposedly magical objects that were called glossopetrae, or "tongue stones", as the teeth of sharks.