Complex sentence: The Christmas Island pipistrelle was endemic to the island; the last individual was recorded in 2009, and, in 2016, the species was assessed extinct by the International Union for the Conservation of Nature.
Split into simpler sentences: The Christmas Island pipistrelle was endemic to the island until 2009, when the last individual was recorded. In 2016, the species was assessed as extinct by the International Union for the Conservation of Nature.