NOT knots on a Log

I got a couple of good close-up alligator shots today, but I had to share this pair of turtles on a long. They were about 1 foot in diameter, so they were not small pond turtles.  One of them is green, and it looked like a fungus or grass was growing on his shell.  They appeared to be different species, but still share a log.  Please notice their reflections.  The alligator was about  10 - 15 feet away resting in the tall grass in the water. I guess he was only about 5 feet long, but he showed me a set of very white teeth.