Trapped Bird

Trapped Bird is an Expert Track unlocked at Rank 38. It is a chunk of amber with what appears to be a bird trapped inside it. The bloons go around the amber and exit at the top of the screen. There are two openings, both on the left side of the screen. This track is similar to Death Valley, but the tracks' positions are reversed, the shorter one being further up the screen than the long one. The tracks never cross.

Trivia

 * The bird trapped inside is actually a dinosaur known as Iberomesornis.
 * Yes, there has been findings of amber with birds (or, in this case, dinosaurs) trapped inside.