50 million years ago in what is now northwestern Colorado, a katydid died, sank to the bottom of a lake and was quickly buried in fine sediments, where it remained until its compressed fossil was recovered in recent years. When researchers examined the fossil under a microscope, they saw that not only had many of the insect’s hard structures been preserved in the compressed shale, so had several internal organs and tissues, which are not normally fossilized.
Click here for original story, 50-million-year-old katydid fossil reveals muscles, digestive tract, glands and a testicle
Source: ScienceDaily