"P"rehistoric Aviation  

Panel 1: 

Two pterodactyls are sitting on a park bench on a sunny afternoon. Pterodactyl 1, who is sitting on the left, looks over to pterodactyl 2, who is sitting on the right.

 

          Pterodactyl 1: "Hey, want to hear a joke?"

          Pterodactyl 2: "Sure."

Panel 2:

Pterodactyls are sitting in the same positions on the park bench.

          Pterodactyl 1: "Why can't you hear a pterodactyl in the bathroom?"

          Pterodactyl 2: "Why?"

Panel 3:

Pterodactyl 1 enthusiastically smiles at pterodactyl 2.

          Pterodactyl 1: "Because the "P" is silent." (exaggerated smile waiting for a response)

          Pterodactyl 2: " ... " (blankly stares at Pterodactyl 1 unimpressed)