Possibly the most misidentified fossils are fossil teeth, claws, and horns. Many people find rocks and fossils they think are dinosaur claws or teeth. No dinosaur fossils have been found in Kentucky. There are many types of fossils that have tooth or horn-like shapes. Some of these non-bone fossils are abundant in Kentucky and easily confused with claws or horns.
Horn corals have horn, tooth, and claw shapes. They often have wrinkles or segments on the exterior, which are not seen in bones. In cross section, they have radiating lines that also are not seen on bones. Click here for more pictures of horn corals to compare with your fossil.
Cephalopods can have horn-like shapes. They were actually the shells of squid-like animals. The exterior of the cephalopod shells is often segmented, which is not seen in bone. Sometimes, the interior cast or mold of a cephalopod shell is preserved as a fossil. This forms a smooth tubular fossil that could be misidentified as a fossil horn or bone. Internal molds and casts tend to have a smooth or irregular interiors, but are not polished on their exterior, or have the interior spongy texture typical of bone. Click here for more pictures of cephalopods to compare with your fossil.
Many plant fossils have tubular shapes that can be confused with horn, tooth, and claw fossils. Fossil Calamites, were a type of reed. These may have lines or ridges along the length of the fossil that may appear similar to the lines seen on some horns. These fossil reeds, however, are generally segmented, unlike bone. They also lack a spongy interior, which is typical of bone. Click here for more pictures of plant fossils to compare with your fossil.
In Kentucky, true fossil horns are rare. In northern Kentucky, bison fossils have been found. In most cases the horns are still attached to the skull. Horns exhibit elongate lines or ridges aligned along the long axis of the fossil. There are bumps toward the base of the horns, similar to cow and deer antlers. The interior of the horns has a spongy texture. Tusks of mammoths and mastodons, which have been found in Kentucky are horn shaped, but are actually teeth (see below).
In Kentucky, fossil teeth from fish, reptiles, and mammals have been found, but are rare. The exterior surfaces of most fossil teeth are smooth, and may have a polished appearance. Some teeth are sharp and serrated. Others are not. Reptile and fish teeth tend to be sharp, and often triangular to cone-shaped. They are generally very small (millimeters to 2 cm). Mammal teeth are more diverse in shape, but usually have the appearance of modern mammal teeth with roots and crowns. In fact, it can be difficult for the amateur collector to differentiate the teeth of relatively modern horses and cattle from fossil horses and bison.
Large fossil tusks, such as those on mammoths and mastodons, are also teeth, and have been found in Kentucky. These tusks may have a shiny, polished (ivory-like) exterior. This exterior may have fine cracks in it, like the cracks in old porcelain. The polished surface, however, will only be a thin rind on the outside of the tusk. Generally, when fossil tusks weather, they peel apart in concentric layers. Beneath the polished outer layer will be more thin layers, of different textures. Some may be rough. Some may have the spongy texture of bone. Others may be powdery. Other types of fossils, such as horn corals, which may have a tusk-like shape, will not weather or split apart in concentric layers.