Psaronius

Psaronius is an extinct genus marattialean tree fern which grew to 10m in height, and is associated with leaves of the organ genus Pecopteris and other extinct tree ferns. Originally, Psaronius was a name for the petrified stems, but today the genus is used for the entire tree fern. Psaronius tree fern fossils are found from the Carboniferous through the Permian. thumb|left|Reconstruction of Psaronius, Illustrated by Auguste Faguet (1877)

== Etymology == The word Psaronius comes from the Greek ψαρονιος (psaronius, precious stone) the root of which is ψαρον (psaron, a starling bird.] The stone was used for ornamental purposes in Europe and acquired the name for its resemblance to the speckled pattern of the starling. In Germany, the stone was called staarstein. And in English, it was called either starry-stone or starling stone.