Pterodactyl Defense: Western, Pterodactyl

The Pterodactyl Defense: Western, Pterodactyl is a chess opening classified under ECO code B27 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 c5 2. Nf3 g6 3. c3 Bg7 4. d4 Qa5. The resulting position leaves white to move.