Species diverges from common ancestors through changes in their DNA. Duplicated genes that impart new roles from their ancestors can be co-opted by changing their regulation process or altering their coding proteins to promote developmental and physiological features (Carroll, 2000; True and Carroll, 2002; Conant and Wolfe, 2008). A complex tripartite brain especially telencephalon is a key trait of vertebrates (Murakami et al., 2005; Sugahara et al., 2013, 2016). The highly plastic vertebrate brain influences all the basic biological functions, advance order processing and behavior control (Koscik and Tranel, 2012). As the most important part in organisms, however, it is hard to trace brain evolution because brains themselves are rarely fossilized. Hence, to explore the evolutionary origin of vertebrate brain needs to rely on molecular evolution and developmental studies.