Small circular fossils (less than a few centimeters in diameter)

1. Crinoid columnals are generally small circular fossils, a centimeter or less in width. They may have a hole toward the axis (bead shape) but are common without holes as well. Crinoid columnals are common in limestones and shales throughout Kentucky, especially central Kentucky and around Cumberland Lake.
2. Cross sectional views or views looking down on the tops or cups of horn corals can have a circular appearance. Most corals will have grooves or lines radiating out from the axis. They are generally less than 3 or 4 centimeters in width.
3. Cross sectional views through some types of bryozoans are circular. Such sections are generally less than a centimeter in width and are common in Ordovician limestones of central Kentucky.
4. Atrypa, Orbiculoidia, and some productid brachiopods have circular shapes at certain orientations and do not have grooved ornamentation like many other shelled fossils. Look to see if you can see a tiny protrusion on one side of the shell that might be a hinge to the shell valves.

Larger circular fossils

1. Some horn corals and tabulate corals are circular in cross section or when looking down from the top. Tabulate coral mounds may have diameters from centimeters to more than a meter across.

• This shape is common for crinoid columnals. These are generally less than a centimeter across. Amateurs often refer to these fossils as Indian beads.

1. Cross sectional views or views looking down on the tops or cups of horn corals can have a circular appearance. Most corals will have grooves or lines radiating out from the axis. They are generally less than 3 or 4 centimeters in width.
2. Cross sectional views through some types of bryozoans are circular. Such sections are generally less than a centimeter in width and are common in Ordovician limestones of central Kentucky. Bryozoans have a different appearance in section from corals. To tell them apart look at the pictures in the Fossils by type section of this web site.
3. Some crinoid columnals will also have radiating lines outward from center. Most will also have a hole or depression in the center, and will be small, generally less than a centimeter in diameter. They will be bead-like if separated from the rock they are found in. In contrast, bryozoans with circular cross sections will be tubular, and horn corals will often be conical or cup-shaped.

Bead with radiating lines or grooves

• Some crinoid columnals will also have radiating lines outward from center. Most will also have a hole or depression in the center, and will be small, generally less than a centimeter in diameter. They will be bead-like if separated from the rock they are found in. In contrast, bryozoans with circular cross sections will be tubular, and horn corals will often be conical or cup-shaped.

Circle with hole and radiating lines

• This shape is typical of some crinoid columnals. These are generally less than a centimeter across.

Bead with hole and radiating lines

• This shape is typical of some crinoid columnals. These are generally less than a centimeter across.

• This is a crinoid columnal. These are generally less than a centimeter across.

Bead with star axis

• This is a crinoid columnal. These are generally less than a centimeter across.

No fossil eggs are known to have been found in Kentucky. Fossil eggs worldwide are very rare. In most cases an egg-shaped fossil is something else.

• Most fossil "eggs" reported in Kentucky are weathered and rounded rocks, rather than fossils. Siderite nodules can have smooth, oval shapes and may appear like eggs. Other rocks may be rounded in streams into oval shapes.
• Some brachiopods have oval shapes, but are generally small. If weathered or partially covered in rock, it may be difficult to see shell ornamentation typical of most brachiopods.

• Many nut-shaped fossils are fossil echinoderms called blastoids. These are especially common in Mississippian strata.
• Some brachiopods, including the productids have an acorn-like shape.
• True fossil nuts are a type of plant fossil, which are rare in Kentucky. They could be found in the Jackson Purchase region.

Pentagonal symmetry is common to echinoderms. Several types of fossil echinoderms can be found in Kentucky.

• Top view of a crinoid calyx.
• Fragmentary plates of crinoids, blastoids, and other echinoderms.

5-pointed star shapes

Stars are generally five-sided in fossils, and this type of symmetry is common to echinoderms. Several types of fossil echinoderms can be found in Kentucky.

• Top view of a blastoid calyx, often has a star-shape on it. It can look like a starfish on a blastoid.
• A star-shaped hole in the center of a circular fossil is typical of some crinoid columnals.
• True starfish fossils are rare but can be found in limestones.
• Some fossil plants may have narrow leaves around a central stem, causing a star-like shape. There will generally be black (carbon) in gray shale, and from the coal fields.

Cross sectional views through the valves of shelled animals such as brachiopods and bivalves are most common.

• If two valves are preserved, and the valves are the same (mirror images) the fossil may be a bivalve (clam).
• If two valves are preserved, and the valves are slightly different in shape, the fossil is probably a brachiopod.

Small spiral fossils (less than a few centimeters in width)

• Most commonly gastropod (snail) fossils.
• Some coiled shapes may also be goniatites, a type of small ammonite. These are not common fossils, but occur in dark shales of Devonian through Pennsylvanian strata. Often they are the same color as the shale, which makes them hard to say.
• Some graptolites are coiled. These are easily differentiated from gastropods and goniates, in that they have saw-toothed edges.

Large spiral fossils (more than six centimeters across)

• Large coiled shapes are most commonly cephalopods.

Fossil shells are the most common types of fossils found in Kentucky. There are many kinds.

• Most shells found in Kentucky are fossil brachiopods. In fact, brachiopods are the official State fossil of Kentucky. There are hundreds of different kinds of fossil brachiopods. Many brachiopods have ridges or grooves that radiate from the hinge between the valves toward the front of (across) the shell.
• Some shells found in Kentucky are fossil bivalves (clams). Clams have two valves (shells) that are the same (mirror images), whereas brachiopods have two shells that are different. Clams are not as common as brachiopods in most Kentucky strata. Grooves or ridges on clams are very fine and appear as lines oriented symmetrically around the shell like a modern clam, rather than across it, as is common in many brachiopods.

• A type of coral fossil, called Favosites, has a diagnostic hamhock shape when viewed from the side. From a top view, they are circular. These occur in Devonian limestones.

• Fossil stromatoporoids commonly occur as irregular mounds. They may also occur as mats, and coatings on other fossils. In Devonian strata they may look like peeling onions, or fossil manure. Some may look like brains.
• Weathered corals may appear as irregular mounds. Look for holes or honeycomb shapes to differentiate from stromatoporoids. Some may even look like brains.
• bryozoans commonly occur as irregular mounds. Most are small, only a few inches across.
• Sponges

• Stromatoporoids

• Several types of fossil corals have a honeycomb appearance. These honeycombs may be small (less than a few cm) but may occur in groups or colonies more than a meter in diameter. These types of corals are found in Silurian, Devonian, and Mississippian limestones.

• Several types of fossil corals occur as mounds with holes in them. The holes are generally tiny (less than a mm each). Mounds range in size from a few centimeters to meters in width. These types of corals are found in Silurian, Devonian, and Mississippian limestones.

• Horn corals commonly have cup shapes. If you can see inside the cup, corals will have grooves or lines radiating out from the axis. They are generally less than 3 or 4 centimeters in width.
• A type of bryozoan found in limestones of central Kentucky has a "chocolate-drop" or cup shape.
• The calyx of a crinoid has a cup shape. Almost always associated with bead-like crinoid columnal fossils.
• The calyx of a blastoid has a cup shape. Almost always associated with bead-like blastoid columnal fossils (indistinguishable from crinoid columnals). Most common in Mississippian strata
• A type of trace fossil called Conostichus, often has a cup shape. The bottom of the cup may have a small bulb or protrusion at the base. Sometimes the bulb is 5-sided, which is why this trace fossil is thought to be the resting trace of a sea urchin, a type of echinoderm. These ichnofossils generally are composed of sandstone or siltstone, and are found in Pennsylvanian strata, often devoid of other fossils.

• Horn corals commonly have cup shapes with closely spaced ridges or grooves radiating outward from the central axis. They are generally less than 3 or 4 centimeters in width, but some may be larger in Devonian strata.

• A type of trace fossil called Conostichus, often has a cup shape. The bottom of the cup may have a small bulb or protrusion at the base. Sometimes the bulb is 5-sided, which is why this trace fossil is thought to be the resting trace of a sea urchin, a type of echinoderm. These ichnofossils generally are composed of sandstone or siltstone, and are found in Pennsylvanian strata, often devoid of other fossils.

Most of the tooth-shaped fossils found in Kentucky are not fossil teeth. Rather they are fossils of other animals.

• Horn corals are the most common type of fossil with a tooth shape, especially in cross section. If you can see inside the cup, corals will have grooves or lines radiating out from the axis. They are generally less than 3 or 4 centimeters in width.
• Siderite nodules can have a tooth shape and are sometimes mistaken as fossils. These mineral nodules are not fossils. They are red to brown in color and when scratched upon a piece of ceramic will leave a reddish brown streak. They are common in Kentucky's two coal fields.
• Fossil plant roots, can sometimes have a conical shape that could be misidentified as a tooth. These are relatively common in Kentucky's two coal fields.
• Connularids are cone- to tooth-shaped fossils that have transverse ribbing, that looks like fish-bones up the sides of the cone. These fossils are uncommon to rare.
• Fossil shark's teeth have been found in Mississippian and Pennsylvanian strata in the State. Most tooth and bone material found to date has a dark black to bluish shine. These types of fossils are rare.
• A large fossil fish called an arthrodire, had a hook-shaped lower jaw, that looks like a tooth. These are rare fossils, but have been found in Devonian strata. The hooks are generally more than 10 cm in length, and black to gray in color.

• Most of the horn-shaped fossils found in Kentucky are not fossil horns. Rather they are fossils of other animals.
• Horn corals are the most common type of fossil with a horn shape. If you can see inside the cup, corals will have grooves or lines radiating out from the axis. They are generally less than 3 or 4 centimeters in width, but some grew to lengths of more than a meter. Large horn corals are most common in Devonian strata in Kentucky.
• Some fossil horns reported in Kentucky have turned out to be cephalopods. These fossils are common in central Kentucky and can be more than a meter in length.
• Siderite nodules can have a tooth shape and are sometimes mistaken as fossils. These mineral nodules are not fossils. They are red to brown in color and when scratched upon a piece of ceramic will leave a reddish brown streak. They are common in Kentucky's two coal fields.
• Fossil plant roots, can sometimes have a horn shape. Large fossil tree roots called Stigmaria, may be pointed at one end, and will be covered with many large holes or circular depressions. These are relatively common in Kentucky's two coal fields.
• Connularids are cone- to horn-shaped fossils that have transverse ribbing, that looks like fish-bones up the sides of the horn. These are uncommon fossils, and are generally small, less than 5 or 6 cm.
• A large fossil fish called an arthrodire, had a hook-shaped lower jaw, that could be mistaken for a horn, especially in large arthrodires (some of these fish were as large as great white sharks). These are rare fossils, but have been found in Devonian strata. The hooks are generally more than 10 cm in length, and black to gray in color.
• Tusks of mammoths and mastodons are rare but have been found in salt licks and sink holes, especially in northern Kentucky. These tusks are generally very large and easily distinguished from other possible fossil types.

Most of the horn-shaped fossils found in Kentucky are not fossil horns. Rather they are fossils of other animals

• Horn corals are the most common type of fossil with a horn shape and segmented ridges. If you can see the top of the fossil, a coral will have a cup-like depression. The cup will have grooves or lines radiating out from the axis. They are generally less than 3 or 4 centimeters in width. but some grew to lengths of more than a meter. Large horn corals are most common in Devonian strata in Kentucky.
• Some fossil horns reported in Kentucky have turned out to be cephalopods. These fossils are common in central Kentucky and can be more than a meter in length. The segments are generally well spaced, half a centimeter to a couple of centimeters apart.

Most of the horn-shaped fossils found in Kentucky are not fossil horns. Rather they are fossils of other animals

• Connularids are cone- to horn-shaped fossils that have transverse ribbing, whichlooks like fish-bones up the sides of the fossil. These are uncommon fossils.

Small tubes (less than a few centimeters in width)

• Broken bryozoans can have tubular shapes, especially in central Kentucky. Most will be a centimeter or less in diameter and only a few centimeters in length. Especially common in limestones of central Kentucky.
• Some branching corals when broken have tubular shapes. Tubular branches of corals are common in Devonian strata. Look for pin-holes along the tube.
• Crinoid columns are tubular. They are generally segmented. Most are less than a centimeter in width, and are commonly associated with broken columnal debris, which are circular or bead shaped.
• Siderite nodules can have a tubular shapes and are sometimes mistaken as fossils. These mineral nodules are not always fossils. Sometimes the siderite filled ancient burrows of animals, in which case the tubes represent what are called trace fossils, or ichnofossils. Siderite is red to brown in color and when scratched upon a piece of ceramic will leave a reddish brown streak. These nodules are common in Kentucky's two coal fields.

Large tubes

• Large tubes, more than a centimeter in width or ten centimeters in length may be cephalopods. Cephalopods commonly have segmented shells. Cephalopod shells may be conical, narrowing at one end.
• The reed-like Calamites occur in Kentucky's two coal fields. It often exhibits grooves parallel to the long axis of the tube, and may be segmented like bamboo. Most fossils are four or more centimeters in diameter, and generally tens of centimeters in length.
• Fossil tree roots called Stigmaria, occur in Kentucky's two coal fields. They often exhibit small circular depressions or holes along the long axis of the tube. Most fossils are four or more centimeters in diameter, and generally tens of centimeters in length.

• Tubes that are attached together are generally coral fossils. The corals Halysites and Syringopora consist of very narrow tubes (mm thick), attached together in organ-like shapes when viewed from the side. From the top, the tubes are arranged like chain in Halysites. These are common in Silurian strata.

• Tubes with holes are generally bryozoan or coral fossils. Bryozoans with this shape are most common in Ordovician strata in Kentucky, while corals with this shape are more common in Silurian and Devonian strata. -large holes (more than a mm) are mostly corals. -tiny holes can be either bryozoans or corals. -star-shaped holes are bryozoans
• Stromatoporoids can also be tubular with small holes. These are ancestors of calcareous sponges. The stromatoporoid Amphipora is a tiny branching tube that is common in some Devonian strata. It often branches.

• Crinoid columns are tubular and very common in limestones and shales of the State. Most are less than a centimeter in width, but they can range in length to tens of centimeters. Segmented columns, are commonly associated with broken columnal debris, which are circular or bead shaped.
• Long, segmented tubes may be the shells of cephalopods. Most are 2 to 5 centimeters in width, and tens of centimeters in length. Cephalopod shells may be conical, narrowing at one end.
• The reed-like Calamites is a common fossil in Kentucky's two coal fields. It often exhibits grooves parallel to the long axis of the tube, and may be segmented like bamboo. Most fossils are four or more centimeters in diameter, and generally tens of centimeters in length.
• Some arthropods such as millipedes can also appear as segmented tubes, but these are very rare. Only one has been found in Kentucky and it occurred in a dark shale of the Western Kentucky Coal Field.

Most fossils found in Kentucky that look like flowers, aren't. Here are some possibilities.

• The most commonly misidentified fossils with flower shapes are types of plant fossils called sphenopsids. Annularia is a good example. The fossils look like flowers on a stem, but are actually circles of leaves, rather than flower petals. These types of fossils are common in Kentucky's two coal fields, and often occur as black fossils in gray shale.
• Flower shapes in limestone, are most often 5-sided and are fossils of echinoderms. The top view of a blastoid calyx, often has a flower-shape on it. It can look like a starfish on a blastoid.

• Some needle-shaped fossils are plant fossils, similar to pine needles. Lycopod trees sometimes had needle-like leaves. They are often black (from organic carbon like coal) and occur in dark gray shales of Kentucky's two coal fields.
• Another type of plant fossil with needle shaped leaves were the sphenopsids. Annularia is the needle- or flower-shaped fossil. They are often black (from organic carbon like coal) and occur in dark gray shales of Kentucky's two coal fields.
• In limestones, needle-like fossils may represent the spines of sea urchins, a type of echinoderm. These are not commonly recognized but occur in Mississippian strata.
• In Ordovician shales and limestones, some bundles of needle-like fossils may be graptolites.

• Segmented tubes with rounded ends are generally fragments of cephalopod shells. Most are 1 to 3 centimeters in width, and only a few centimeters in length.
• Fossil plant roots, may have rounded ends. These are common in Kentucky's two coal fields. Usually they are a cast of a root mold and will be composed of sandstone or siltstone. Sometimes the sandstone is mineralized so that is reddish, brown, or yellow in color.

• Long, segmented tubes that come to a point or are conical in shape are most likely the shells of cephalopods. They are common in Ordovician strata of central and northern Kentucky, but can occur elsewhere.

• In limestone, branching fossils are most commonly bryozoans, especially in central Kentucky. Some bryozoans have star-shapes on the branches
• Some corals also can have branching shapes. Branching corals are common in Devonian strata.
• Fossil plant branches occur in Kentucky's two coal fields and generally occur as black branches in gray shale or siltstone. They commonly are associated with other plant debris, like fern leaf fossils.
• The stromatoporoid Amphipora is a tiny branching tube that is common in some Devonian limestones.

• Most screw-shaped fossils are Archimedes, a type of bryozoan common in Mississippian strata. These often occur in association with mesh-shaped fossils, which represent the fronds that grew off the screw-shaped axial column of this bryozoan.
• Some screw-shaped fossils are the remains of the axial regions of cephalopods
• Some screw-shaped fossils are the remains of the axial regions of gastropods (snails). These will usually be coiled screws, but when fragmented may look like a single straight screw.

• The only common fossils with saw-toothed edges are graptolites. These are generally narrow (mm's across) and dark gray to black. They can form mesh-like patterns, and occur in Ordovician strata.

• Chain shapes are common on the top surface of a type of fossil coral called Halysites, which is found in Silurian strata. Tubes or straight lines should extend downward beneath the chains.
• String of Pearls. Some chains of beadshapes are a type of trace fossil called Scalarituba. They will generally be round beads and the same color and texture as the surrounding rock.

• Most sinuous shapes are trace fossils, also called ichnofossils. Trails of worms, snails, and other invertebrates can be preserved as fossils and leave a sinuous shape. Often the shape is the same color and texture as the surrounding rock.

Many rocks and fossils may have bone-like shapes. MOST are not bone.

• siderite
• cephalopod--long tubes
• large horn corals

Real bone

• Fossil insects are extremely rare in Kentucky. However, rolly-polly-like arthropods called trilobites are common to uncommon in Ordovician, Silurian, and Devonian strata. Whole trilobites have three lobes or portions to their bodies.
• A single millipede fossil has been found in the Western Kentucky Coal Field, and fossil arthropods are known from coal fields in other areas, so that more may be found in Kentucky. However, these are very rare types of fossils.
• A single insect wing fossil has been found in the Eastern Kentucky Coal Field, and fossil insects are known from coal fields in other areas so segmented, bug-like insect bodies may be found in the future, however, most reported insect wing fossils turn out to be fossil fern leaves. Veins within the fossil do not radiate outward from a mid-line or stem as in a leaf.

• Several brachiopods, including Lingula, have tear-drop shapes and are common in dark shales of Kentucky's two coal fields.
• A type of bryozoan called a chocolate-drop bryozoan, would have a tear-drop shape in cross section. If hole, it will have a diagnostic chocolate-drop shape. These only occur in Ordovician strata.
• Fossil plant leafs are common in Kentucky's two coal fields and in clay pits of the Jackson Purchase area. Most leaf fossils from tbe coal fields are fossil fern leaves. These can occur as isolated, tear-drop shaped fossils. Fern leaf fossils generally have a central ridge or elongate furrow, with tin lines or veins arching away from the ridge, similar to modern fern leaves. They are often black (from organic carbon like coal) and occur in dark gray shales. Leaf fossils are very common in Kentucky's two coal fields.

• Several brachiopods, including Lingula, have tear-drop shapes and are common in dark shales of Kentucky's two coal fields. These may have thin ridges or segments, which represent growth lines on the shells.

• Several brachiopods, including Lingula, have tear-drop shapes and are common in dark shales of Kentucky's two coal fields. These may have thin ridges or segments, which represent growth lines on the shells.

• Mesh-shaped fossils are most commonly a type of bryozoan called fenestrate bryozoans. They are most common in Mississippian strata.
• In Ordovician strata, graptolites can form mesh-like patterns. These will often be associated with segments that have a saw-tooth pattern.

• Mesh-shaped fossils are most commonly a type of bryozoan called fenestrate bryozoans. They are most common in Mississippian strata.
• In Ordovician strata, graptolites can form mesh-like patterns. These will often be associated with segments that have a saw-tooth pattern.

• A common misidentification of fossils occurs with scaly shapes. Amateur collectors often report finding fossil snake skin, especially in Kentucky's two coal fields. These fossils are actually the imprints of fossil lycopod tree bark. Some may look like pineapple skin, others like reptile skin.

Tire tracks

• A common misidentification of fossils occurs with scaly shapes. Amateur collectors often report finding fossil snake skin, especially in Kentucky's two coal fields. These fossils are actually the imprints of fossil lycopod tree bark. Some may look like pineapple skin, others like reptile skin.

• Chevron-ridged or indented markings are usually trace fossils, also called ichnofossils. Trails of worms, snails, and other invertebrates can be preserved as fossils and leave many different kinds of shapes. Often the shape is the same color and texture as the surrounding rock.

Traces of invertebrates on the bottom or in the sediment

• Rhizocorallium trace
• Zoophycos trace