Paleontology
The Lance Formation was laid down by streams, on a coastal plain along the edge of the Western Interior Seaway. The climate was subtropical; there was no cold season and probably ample precipitation. Most of the animals known from the formation are freshwater animals, and some are exclusively freshwater forms (for instance, frogs and salamanders). However, marine fossils are also found in the formation, suggesting that the sea was nearby. The bird fauna is mainly composed of orders still existing today.
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