About Sphenophyllum emarginatum
Sphenophyllum emarginatum is an extinct species of ancient horsetail plant. The name comes from Greek meaning sphen = Wedge and phullon = Leaf. It gets this name from the distinct shape of the leaves. Apparently these plants could grow to about a meter in height. The leaves would grow out from the stem instead of a branch like most plant of today
Age and Distribution
Sphenophyllum emarginatum thrived during the Carboniferous as it is found almost everywhere in the world, during this time the Earth was a lot warmer and experienced almost no seasons (it was mostly a tropical enviroment). So it was ideal for plants. This specimen was found near Osnabrück in Germany. Where an old volcano burst through the crust a long time ago and took many of the top layers with it. After it eroded away it left the Carboniferous exposed. At that time this region was home to a series of lakes and rivers. From time to time a flash flood would occur and take everything with it. That is why the rocks are stuffed with fossils and not (finely) layered. Other flora and fauna that lived at this location were the plants Calamites, Asterophyllites equisetiformis, Neuropteris attenuata and many more. One could also encounter small horseshoe crabs here like the Euproops bifidus and many insects like dragonflies.
About the Sphenophyllales Sphenophyllum emarginatum
During the Carboniferous a lot of plants became fossilized and were turned over time into fossil fuels, which we use today. The Osnabrück quarry still gets mined for that same reason, although they do keep certain sections available for research. Earliest found sphenophyllum date back from the late Devonian period. The Sphenophyllum was very succesful during Carboniferous but dwindled and became extinct in the late Perm(no specimens from after this time have been found).
Sphenophyllum emarginatum belongs to the Sphenophyllaceae which is a subclass of the Sphenophyllales. There are at least 20+ species known and most are from the Carboniferous.