 The sicklefin lemon shark may also be referred to as broadfin shark, Indian lemon shark, Indo-Pacific lemon shark, or simply lemon shark.Based on microsatellite DNA evidence, the sicklefin lemon shark is thought to have diverged from its sister species "N. brevirostris" 10–14 million years ago, when the closure of the Tethys Sea separated lemon sharks in the Indian Ocean from those in the Atlantic.The ancestral lemon shark species may have been "N. eurybathrodon", the fossilized teeth of which occur in both the United States and Pakistan.