Did you know that the tail spikes on the end of a stegosaur's tail was named the "thagomizer" after a Far Side comic?

Camponology is the tuning of bells.

Christmas trees are actually black spruce, not pines. The difference is that spruces are tapering columnar trees with square needles in bunches of three or four, while pines are clumpy irregular trees with round needles in bunches of two, three or five. In addition, pine female cones hang down, while spruce female cones point up.

Hoplites were greek, not roman.

Technetium does not occur in nature.

Polar bears have clear fur.

Black swan males sometimes pair up with other males, then proceed to "adopt" one or two eggs from a female nest and raise them as their own. 

We have cloned cats.