I have many pictures of the Happy-face Dragonfly sitting on my finger. I decided to convert one of them to a drawing. Notice the paddle-shaped appendages – which are responsible for its official common name, the Paddle-tailed Darner – and the presence of a light-colored spot on the tenth segment of the tail (abdomen).
The official name, Paddle-tailed Darner, isn't particularly apt because a number of different species have paddle-shaped appendages. For example, the Shadow Darner, Walker's Darner, and the Lance-tipped Darner all have appendages with a similar paddle shape. This leads to confusion because people often think that paddle-shaped appendages must be distinctive to the Paddle-tailed Darner, and are surprised to find the same shape in other darners.
In addition, the use of "tailed" in the name is unfortunate, because "tail" usually refers to the abdomen, not the appendages. As an example, the Common Whitetail has a white abdomen (tail); similarly, the Red-tailed Pennant has a red abdomen (tail). On the other hand, the Brush-tipped Emerald has appendages (tips) that are brush shaped. So, the Paddle-tailed Darner has a name that is not particularly appropriate – of course, I think it's official name should be the Happy-face Darner!
It's been a long time since I seen one of these guys, much less had one on my finger. I'm looking forward to becoming reacquainted with them later this year. In the meantime, here's a YouTube video slideshow of a variety of dragonflies on my fingers: Slideshow.