This week’s Fossil Friday features an osteoderm of a crocodylian. This osteoderm was found at the Lirio East site of the Culebra Formation and is early Miocene in age. Osteoderms are bony plates that form in the dermal layers of the skin (dermal bones) and are found in many reptiles and amphibians. In crocodylians, many of these bony plates are embedded in the skin and act as a form of armor. Osteoderms are also heavily vascularized in modern crocodylians, allowing them to absorb heat when they are basking in the sun.