ANNELIDS are a group of segmented worms which includes leeches and common earthworms. Typically, they are composed of a varying number of rings or segments. Marine, fresh water and land forms have been common throughout much of geologic time, but are not usually preserved due to the lack of hard parts. Although minute jaw pieces of marine worms and limy worm tubes have been found from the Ordovician period, most evidence comes from fossil worm borings, burrows, trails, castings.
The large worm burrows on the next page were removed from limestone rocks. The smaller atypical "worm trails" have been given a coating of shellac to reveal details of a possible cast or calcareous tube.