The Siphonophrentis elongata (Rafenesque & Clifford, 1820) horn coral fossil is one of the largest found in the United States. This picture shows a small fragment of the original specimen. It was well over 30 cm in length when it was alive during the Middle Devonian Period. This segment is about 5 cm long and almost 8 cm in diameter.
What is nice is the center on one end is full of crystals (maybe quartz or calcite) and smooth mineral layer at the other end. The septa divisions are still visible along the outer circumference of the horn coral fossil.
It was found in the Jeffersonville Limestone of Jefferson County, Kentucky, USA.
Notice the beekite patterns on the outer surface of the fossil in this next picture.
