These are fossilized carboniferous branches of a Lepidodendron tree (out of the crown of the tree). With a very good contrast! The Lepidodendron tree was a primitive vascular scale tree, that could reach heights of 50 metres!!! The leaves are also well preserved, needle-like coming out of the sides of the twigs. The leaves were only present on thin and young branches. The Lepidodendron trees were found until the Late Triassic. The stone was found by myself in Germany in March 2026, region of the city Saarbrücken and is between 309 and 302 million years old.