Pterodactyl Defense: Eastern, Pterodactyl

The Pterodactyl Defense: Eastern, Pterodactyl is a chess opening classified under ECO code B06 in the Semi-Open Games family, where Black responds to 1.e4 with something other than 1...e5, including the Sicilian Defense, Caro-Kann, and Pirc. It is reached after 4 moves: 1. e4 g6 2. d4 Bg7 3. Nc3 c5 4. dxc5 Qa5. The resulting position leaves white to move.