There are still many species of bryozoans alive today, living in both fresh and salt water. A few kinds of ancient bryozoans. Each coral colony is made up of polyps, tiny individual animals, that create a hard skeleton around themselves. After many years these colonies may form entire reefs. A piece of fossilized coral.
Most horsetails grow in wet, swampy areas or at the edge of ponds or lakes.
They have hollow stems that are jointed. At each joint is a ring of small tooth-like leaves. Some stems have many branches. Today, horsetails are small plants, but in the ancient past, they grew quite large.