Sirenia fossils are very common in the Peace River originating from the Dugong, a manatee-like siren but with a different tail shape. There are multiple species but the most common is Metaxytherium floridanum. M. floridanum lived during the Miocene around 7-14 million years ago according to the FLMNH. The only fossils that I own from Dugongs are rib bones, however one can also find skull caps, teeth and other bones. The ribs are incredibly dense and lack a porous, spongy, layer that most bone contains. The rib bones may also have apparent growth rings on the cross section. As far as bones in the Peace River go these are the most common due to the density preserving them well.
Ribs
As mentioned rib bones are the most common finds from dugongs. They are solid, rounded and cylinder like. They are often tumbled and broken into smaller sections but can regularly be found in big chunks, especially in areas with larger gravel. The ends are solid with no spongy bone or internal canal. They often contain borings from clams and other invertebrates looking for a snack on the ancient sea floor and ending up leaving holes throughout the bone.
