Identification Guide for Common Fossils from the Cincinnatian of Ohio

Identification Guide for Common Fossils from the Cincinnatian of Ohio
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Brachiopods Identification Guide for Common Fossils from the Cincinnatian of Ohio Gastropods ©2001, John H. Whitmore Assistant Professor of Geology Cedarville University Cedarville, Ohio Drawings by Alison Warren Bryozoans To start, click on A fossil type or click here for information on how to use this program Pelecypods Tentaculitoids Corals Crinoids Trilobites Cephalopods

Brachiopods Click here for brachiopod species Kingdom Animalia
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Brachiopods Click here for brachiopod species Kingdom Animalia Phylum Brachiopoda sulcus Brachiopods are solitary marine organisms that live between two valves or “shells.” They are very common in the Cincinnatian rocks of Ohio. They are externally different from the pelecypods (clams) in that the left and right halves of the brachiopod shells are usually mirror images of each other (see picture below). Internally, brachiopods are completely different from the pelecypods. Brachiopods feed with a special filtering organ called the lophophore which is located between the valves and attached to the brachial valve. The pedicle extends through a small opening or hole in the pedicle valve and is used as an anchoring device. The interior of the brachial valve is important in taxonomic differences between various species. beak hinge fold Dorsal View (brachial valve) Posterior view Anterior view brachial valve (dorsal valve) pedicle lophophore Posterior Anterior pedicle opening beak pedicle valve (ventral valve) growth lines ribs (plications) The symmetry in brachiopod valves is usually perpendicular to the hinge line. If pelecypod valves are symmetrical (and often they aren’t), the symmetry is usually parallel to the hinge. A biconvex brachiopod A concavo-convex brachiopod A convexi-concave brachiopod Symmetry differences between brachiopods and pelecypods

Glyptorthis insculpta Hebertella Hisobeccus capax Holtedahlina sulcata
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Dalmanella meeki Glyptorthis insculpta Hebertella Hisobeccus capax Holtedahlina sulcata Lepidocyclus perlamellosus Leptaena richmondensis Petrocrania scabiosa Plaesiomys subquadrata Platystrophia Plectorthis fissicosta Plectorthis plicatella Rafinesquina ponderosa Rhynchotrema dentatum Sowerbyella rugosa Sowerbyella sp. Strophomena Tetraphalerella neglecta Zygospira modesta

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Dalmanella meeki A small brachiopod, usually 1.5 to 1.8 cm wide. Gently biconvex in profile. The brachial valve has a shallow sulcus. The ribs are finer than Plaesiomys and Glyptorthis. Dalmanella also tends to be smaller than these genera in the Cincinnatian. B– interior of brachial valve C– pedicle view (opposite side of D) D– brachial view (opposite side of C) E– pedicle view (opposite side of F) F– brachial view (opposite side of E) B C D A E F

Glyptorthis insculpta
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Glyptorthis insculpta B– exterior brachial view showing sulcus C– exterior pedicle view D, E– interior brachial view A medium sized brachiopod averaging about 2.5 cm in width. Biconvex profile, brachial valve more inflated and it has a sulcus. The intersection of the radiating ribs and the concentric growth lines produces a reticulate ornamentation on the exterior of the valves (see B). Plaesiomys is similar in external morphology but lacks the reticulate pattern. B A C E D

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Hebertella Large biconvex brachiopod ranging from cm in width. The pedicle valve is usually flatter than the brachial valve. The brachial valve has a large distinctive fold. The pedicle valve has a slight sulcus. Two species: Hebertella alveata and Hebertella occidentalis . B– posterior view C, F– brachial view D– pedicle view E– interior of pedicle valve B C D A F E

Back to Hebertella page
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Hebertella alveata Back to Hebertella page B– brachial view C– pedicle view of B D– brachial view E– pedicle view of E This species of Hebertella lacks the deep fold and sulcus of H. occidentalis. This species is usually smaller in size and has a shallower sulcus on the pedicle valve. The pedicle valve is almost flat. There is a large fold on the brachial valve, but within the fold is a shallow sulcus that extends to the anterior margin, shown well in Fig. D. B C A E D

Back to Hebertella page
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Back to Hebertella page Hebertella occidentalis B– brachial view C, D– pedicle view E– interior of pedicle valve showing characteristic heart shaped muscle scar and triangular pedicle opening This species of Hebertella is characterized by a large fold on its brachial valve (Fig. B) and a deep sulcus on its pedicle valve (Fig C and D). Hebertella alveata does not have a deep sulcus on its pedicle valve and has a very slight sulcus on its brachial valve that extends from the beak to the anterior margin. The pedicle valve is much flatter in H. alveata. C B A E D

Hiscobeccus capax B-- posterior view of beak C– anterior view
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Hiscobeccus capax B-- posterior view of beak C– anterior view D-- brachial view, fold E– brachial and pedicle views Hiscobeccus capax is a small biconvex brachiopod ranging in size from 0.8 cm to 2.0 cm. This species is very difficult to distinguish from Lepidocyclus perlamellosus without looking at its internal morphology. The main difference is that Hiscobeccus is generally smaller and has less distinct growth lines crossing the plications. Smaller specimens of Hiscobeccus tend to be triangular in outline. There are three plications in the sulcus making it different from Rhynchotrema dentatum which only has one plication in its sulcus. B C D A E

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Holtedahlina sulcata A small to medium sized biconvex brachiopod with a deep sulcus in the pedicle valve. Ranges from 1.5 to 2.0 cm in width. Some specimens may be flattened by depositional processes and do not clearly show the sulcus. B– brachial view (fold) C, D– pedicle view (fold) E– anterior view B D C A E

Lepidocyclus perlamellosus
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Lepidocyclus perlamellosus B, C– pedicle view and sulcus showing strong reticulate pattern. Compare to Hiscobeccus capax , figure D. D– anterior view showing three plications in the sulcus E– posterior view Lepidocyclus perlamellosus is a medium sized biconvex brachiopod ranging in size from 2.0 cm to 2.5 cm. This species is very difficult to distinguish from Hiscobeccus capax without looking at its internal morphology. The main difference is that Hiscobeccus capax is generally smaller and has less distinct growth lines crossing the plications. Lepidocyclus is slightly larger and has more distinct growth lines crossing the plications (Figs B and C). There are three plications in the sulcus making it different from Rhynchotrema dentatum which only has one plication in its sulcus. C B A D E

Leptaena richmondensis
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Leptaena richmondensis B A small to medium sized concavo-convex brachiopod ranging from 2-3 cm in width. It is characterized by strong concentric growth lines, but does have fine radiating ribs. B, E– pedicle view C– interior of brachial valve D– brachial view C A E D

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Petrocrania scabiosa A small inarticulate brachiopod with a circular outline ranging in size from 0.5 to 1.5 cm in diameter. It is usually found attached to other brachiopods, like Rafinesquina, as shown in the photos. The radial growth lines of Rafinesquina usually show through the shell of Petrocrania because its shell was so thin. This is illustrated in B, C, and D. C B A D

Plaesiomys subquadrata
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Plaesiomys subquadrata B C A medium sized brachiopod ranging from 2.5 to 3.5 cm in width. It ranges in profile from convexi-concave to unequally biconvex. Subquadrate outline with straight hinge line, width is greater than length. Plaesiomys has a more rectangular outline than Glyptorthis and lacks the reticulate pattern present in Glyptorthis. B, C– Brachial view D--Interior pedicle view E– Exterior pedicle view F– anterior view, brachial valve on top. A D E F

Platystrophia Platystrophia acutilirata Platystrophia clarksvillensis
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Platystrophia Platystrophia acutilirata Platystrophia clarksvillensis Platystrophia cypha Platystrophia laticosta Platystrophia moritura Platystrophia ponderosa auburnensis Platystrophia ponderosa ponderosa There are about 9 species of Platystrophia in the Cincinnatian. Each of the species has subtle differences between them. Important features to look for are the number of plications on each side of the fold or sulcus, the number of plications in the sulcus, size and overall shape. Look at these features carefully in order to differentiate the species in this genera. In the Waynesville area, P. clarksvillensis is probably the most common species.

Back to Platystrophia page
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Back to Platystrophia page Platystrophia acutilirata C A large biconvex brachiopod whose width is significantly greater than its length and has strong radiating ribs. This species is characterized by three nearly equal plications in the sulcus, and a low rounded fold. It has 10 or more plications on each side of the fold and sulcus. About 2.5 cm in width. A– brachial view, showing fold B– pedicle view, showing sulcus C– posterior view D– anterior view D A B

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Platystrophia clarksvillensis Back to Platystrophia page C A large biconvex brachiopod whose width is significantly greater than its length and has strong radiating ribs. This species has almost 3 equal plications in the sinus, and has 8 or 9 plications on each side of the sinus. Both valves are convex to the outer edge to 4.0 cm in width. B– pedicle view, showing sulcus C– brachial view, showing fold D– posterior view E– anterior view B D A E

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Back to Platystrophia page Platystrophia cypha B A large biconvex brachiopod whose width is significantly greater than its length and has strong radiating ribs. This species is distinguished by a strong medial rib in the sulcus, the sides of the pedicle valve are flattened and hollowed out, and there are more than nine plications on each side of the fold. About 3 cm in width. A– brachial view, showing fold B– pedicle view, showing sulcus and strong medial rib C– posterior view D– anterior view showing strong medial rib in sulcus C A D

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit B Platystrophia laticosta A medium sized biconvex brachiopod whose width is significantly greater than its length and has strong radiating ribs. This species has seven ribs on each side of the sulcus and fold and three plications in the sinus, with the medial plication being the strongest to 3.0 cm in width. B– brachial view, showing fold C– posterior view D– anterior view C Back to Platystrophia page A D

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Platystrophia moritura Back to Platystrophia page B A medium sized biconvex brachiopod whose width is significantly greater than its length and has strong radiating ribs. This species has equally developed plications in the sulcus and more than ten ribs on each side of the fold or sulcus. The pedicle valve is convex to the outer edge and is not flattened to 4.0 cm in width. B– posterior view C– brachial view D– anterior view showing ribs in sulcus C A D

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Platystrophia ponderosa auburnensis B A large biconvex brachiopod with an extremely thick shell and strong radiating ribs cm in width. Only slightly wider than long. This subspecies has a short hinge line and great depth to the shell. It is limited to the Mt. Auburn unit. A– brachial view, showing fold B– posterior view C– pedicle view, showing sulcus Back to Platystrophia page A C

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Platystrophia ponderosa ponderosa Back to Platystrophia page A large biconvex brachiopod with an extremely thick shell and strong radiating ribs cm in width. Only slightly wider than long. This subspecies has along hinge line compared to P. ponderosa auburnensis. A– brachial view, showing fold B– pedicle view of another specimen, showing sulcus A B

Plectorthis fissicosta
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Plectorthis fissicosta A small biconvex brachiopod ranging in size from 1.2 to 1.8 cm in width. Notice that the plications in this species are numerous and split, unlike Plectorthis plicatella which are less numerous and do not split. P. fissicosta is also slightly larger. B– pedicle view showing splitting of plications B A

Plectorthis plicatella
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Plectorthis plicatella B A small biconvex brachiopod ranging in size from 0.8 to 1.1 cm in width. Notice that the plications do not split as in Plectorthis fissicosta. P. fissicosta is also larger. B-- posterior view C– pedicle view (fold) D– brachial view (slight sulcus) C A D

Rafinesquina ponderosa
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Rafinesquina ponderosa B A large concavo-convex brachiopod, cm in width. Semicircular outline, with straight hinge line. Width and length are approximately equal. Fine numerous radiating ribs on the exterior of both valves. The brachial valve is concave and the pedicle valve is convex in contrast with Strophomena. B– posterior view C, E– pedicle view D– brachial view C A D E

Rhynchotrema dentatum
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Rhynchotrema dentatum C A small biconvex brachiopod which is distinct from Hisobeccus capax and Lepidocyclus perlamellosus by having only one plication in its sulcus. It ranges from 1.0 to 1.5 cm in width. B B– anterior view C– pedicle view showing single plication in sulcus E– posterior view F– brachial view showing fold D A F E

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Sowerbyella rugosa Small brachiopod with a semi-circular outline and a concavo-convex profile. Wide, straight hinge line. Numerous, very fine ribs cm in width. Distinguished from Sowerbyella sp. by concentric wrinkles along the front margin. B B– pedicle view showing concentric wrinkles along front margin C– brachial view C A

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Sowerbyella sp. Small brachiopod with a semi-circular outline and a concavo-convex profile. Wide, straight hinge line. Numerous, very fine ribs cm in width. Distinguished from Sowerbyella rugosa by a smooth front margin, without wrinkles. C A– mass mortality horizon of Sowerbyella sp. C– pedicle view (convex) D– interior of brachial valve E– exterior of brachial valve (concave) D A E B

Strophomena Strophomena concordensis Strophomena nutans
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Strophomena Strophomena concordensis Strophomena nutans Strophomena planoconvexa Strophomena planumbona Strophomena vetusta Strophomena is a relatively common medium sized concavo- convex species of brachiopod in the Cincinnatian. The species have subtle differences between them and unless you have a pristine specimen, it might be difficult to distinguish between the species. Read the descriptions carefully to distinguish between species.

Back to Strophomena page
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Strophomena concordensis Back to Strophomena page Medium sized brachiopod with semicircular outline and relatively straight hinge line. The brachial valve is convex and the pedicle valve concave. Relatively large size compared to other species of Strophomena, cm wide. This species also has a somewhat triangular outline, delicate striations, and absence of a sulcus and fold. B, C– pedicle view D– brachial view E– interior of pedicle valve B C A E D

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Strophomena nutans Back to Strophomena page This differs from similar species of Strophomena by its strongly triangular outline, delicate striations and a thickening of the anterior margin cm in width. Concavo-convex profile. B– brachial view C– interior of pedicle valve D, E– pedicle view B C A D E

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Strophomena planoconvexa Back to Strophomena page Medium sized brachiopod with semicircular outline and relatively straight hinge line. This differs from other species of Strophomena by having irregular coarse striations and a characteristic muscle scar on the interior of the pedicle valve cm in width. Concavo-convex profile. C B B– pedicle view C– brachial view D– interior of pedicle valve E– pedicle view showing irregular coarse striations A D E

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Strophomena planumbona B– brachial view C– pedicle view D, E– interior of pedicle valve Medium sized brachiopod with semicircular outline and relatively straight hinge line. Differs from similar species of Strophomena by having a relatively small size, rectangular form, and lacking a fold and sulcus cm in width. Concavo-convex profile. C B Back to Strophomena page A D E

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit B Strophomena vetusta A– mass mortality horizon of S. vetusta B– pedicle view C– brachial view, showing wrinkles along hinge line D– interior of brachial valve showing four parallel ridges, distinctive of this species. Medium sized brachiopod with semicircular outline and relatively straight hinge line. Differs from similar species of Strophomena by having four parallel ridges on the inside of the brachial valve (shown in A and D) and wrinkles on the shell near the hinge line (shown in C). Concavo-convex profile, ranges from 2.5 to 3.5 cm in width. C Back to Strophomena page A D

Tetraphalerella neglecta
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Tetraphalerella neglecta This species is very similar to Strophomena, but is different in that it is not strongly triangular, has finer striations, and the impressions on the inside of the brachial valve are very different. It does not have a well defined sulcus or fold. Specimens range from 2.5 to 3.0 cm in width and are concavo-convex. Note the thickness in figure B. B– posterior view C, D– brachial view E– pedicle view C B A D E

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Zygospira modesta A very small biconvex brachiopod with nearly equal length and width mm in width. Circular to sub circular outline with coarse plications. A– pedicle view C– brachial view (sulcus) D– mass mortality zone of Zygospira C A D B

Bryozoans Batostoma Bythopora Constellaria Dekayia Escharopora
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Batostoma Bythopora Constellaria Dekayia Escharopora Homotrypella Parvohallopora ramosa Parvohallopora subnodosa Peronopora Bryozoans Kingdom Animalia Phylum Bryozoa aperture opening monticule lophophore A colony of individual bryozoans or a zoarium. Cross section showing arrangement of individual zooecia. A living bryozoan (zooecium) inside its coffin-like home. Bryozoans are tiny colonial organisms, often mistaken for corals. The individual bryozoan is usually less than 1 mm in size. Bryozoan colonies can be branching, twig-like, fan-like, or encrusting. The entire colony is referred to as a zoarium. Some bryozoan colonies are smooth and others have monticules or bumps covering them. Each small opening or aperture was the home for an individual bryozoan or zooecium. The small animal seals the hole with a “door” or vestibule. They are difficult to identify without microscopic study. Sometimes the pattern of the apertures, size, or shape is characteristic and can be used for generic identification.

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Batostoma B Forms branching colonies. Apertures are elongate and irregularly shaped. Monticules are sparse and when they occur, are not uniformly spaced. Branches range from 2 to 6 mm in size. B– detail of the zooecia apertures C D A E

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Bythopora Forms colonies of very thin stick-like branches. Apertures are elongate and oval. Branches 1-2 mm in diameter. B– detail of apertures B A C

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Constellaria C Forms branching or fan-like colonies. The monticules are strongly star-shaped, making the form unique and easy to identify. A– a sheet-like colony C– detail of star-like monticule showing individual zooecia D– a branch-like colony A B D

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Dekayia B Forms very large branching colonies. The branch diameters are often up to 1 cm in diameter. Apertures are sub polygonal. Monticules are not prominent. B– detail of individual zooecia C A

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Escharopora This bryozoan has a characteristic blade shape with diamond shaped apertures. This specimen is 5.0 cm long. B– detail of individual zooecia. Edge of penny for scale B A

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Homotrypella B Forms hemispherical gum-drop shaped colonies. Apertures are rounded. They usually are found growing on a small broken brachiopod shell. About 1.5 cm in width and height. B– detail of individual zooecia C, D-- views from above and from the side of the same two colonies. C A D

Parvohallopora ramosa
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Parvohallopora ramosa Forms branching colonies with prominent, regularly spaced and sharp monticules. Monticules can sometimes occur in ridges as in Figure D. Apertures are smoothly oval, regularly spaced, and very uniform in shape. This differs from P. subnodosa by having sharp monticules instead of rounded ones. A– detail of individual zooecia (blurry spots are sharp monticules protruding out of the picture). B C A D E

Parvohallopora subnodosa
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Parvohallopora subnodosa B Forms branching colonies with prominent, regularly spaced and rounded monticules. Apertures are smoothly oval, regularly spaced, and very uniform in shape. This differs from P. ramosa by having rounded monticules instead of sharp ones. B– detail of individual zooecia A C D

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Peronopora B Forms colonies of flat, bifoliate sheets. Zooecial apertures are rounded. B– detail of individual zooecia A C

Cephalopods Cameroceras inaequabile Treptoceras duseri
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Cameroceras inaequabile Treptoceras duseri Pelecypods Tentaculitoids Trilobites Exit Cephalopods Kingdom Animalia Phylum Mollusca Class Cephalopoda A living shelled cephalopod. Modern cephalopods, with the exception of one species lack shells. camera (chamber), often containing cameral deposits siphuncle septum suture aperture Cephalopods are members of the phylum Mollusca and include squid, octopi and the pearly nautilus. Cincinnatian cephalopods were straight shelled squids. The siphuncle connects the cameras (chambers) together. The squid could pass air to the chambers via the siphuncle to make it float higher in the water or sink as it swam. apex phragmacone living chamber

Cameroceras inaequabile
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Cameroceras inaequabile Individual shells can exceed 210 cm in length and 20 cm in diameter! The siphuncle is large and may comprise up to ½ of the shell. The siphuncle may not be preserved in many specimens giving the shell a “D” shape or making it flat, if compressed. B A C

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Treptoceras duseri B This is the most common cephalopod in the Cincinnatian of Ohio. It can reach a maximum length of 60 cm. The siphuncle is small and tends to be located near the center of the shell. When the siphuncle is preserved alone, it often appears as a string of beads (as in B). B– siphuncle D– x-section showing siphuncle C A D

A colonial tabulate coral.
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Favistina stellata Grewingkia canadensis Protaraea richmondensis Tetradium approximatum Unidentified coral (?) Corals Kingdom Animalia Phylum Cnidaria corallite corallum corallite growth line septal furrow septum tabulae A colonial tabulate coral. A solitary horn coral. Phylum Cnidaria contains the corals, jellyfish, and anemones. Corals can be solitary or colonial. Corals have a rich fossil record because they excreted a hard calcium carbonate exoskeleton that preserves well. The Cincinnatian solitary corals are quite large, and are “horn” or “tooth” shaped. Individuals in the colonial corals are usually quite small, coralites being 1-3 mm in diameter.

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Favistina stellata A colonial rugose coral forming hemispherical masses up to 10 cm in diameter. The individual corallites are polygonal in cross section. B A

Grewingkia canadensis
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Grewingkia canadensis B A solitary rugose coral that has an elongate and slightly curved corallum. Septa are numerous. Specimens can reach up to 13 cm in length. D– the top of the coral showing the many septa. C A D

Protaraea richmondensis
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Protaraea richmondensis B An encrusting colonial coral. The short septa give each corallite a crenulated appearance. B– Protaraea encrusting a gastropod C– detail of individual corallites C A

Tetradium approximatum
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Tetradium approximatum Colonies form very large hemispherical masses. A– view from above (top view of colony) B– cross section showing long narrow corallites C– cross section showing hemispherical cross sectional shape B A C

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Unidentified coral (?) Unidentified coral. Possibly Streptelasma which when small, forms small encrusting colonies. These may not be coral at all but annelid worm tubes. See Davis, p , Figure 16. B A

Crinoids Cincinnaticrinus pentagonus Cupulocrinus polydactylus
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Crinoids Kingdom Animalia Phylum Echinodermata Class Crinoidea Cincinnaticrinus pentagonus Cupulocrinus polydactylus Iocrinus subcrassus Plicodendrocrinus casei crown arms pinnules calyx column or stalk columnals root Crinoids are echinoderms that live on a long stalk, or column. Their crown is similar to an upside down starfish. Cross sections of the column usually have a tiny star within them. Columns and columnals are the most common parts found, although occasionally a crown or calyx can be found. It is rare to find the entire crinoid preserved. Crinoids are classified taxonomically by the characteristics of their crown, which makes identification of individual columns and columnals difficult unless the crown is attached. Click here for a website on additional Cincinnatian crinoids.

Cincinnaticrinus pentagonus
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Cincinnaticrinus pentagonus The columns are circular and have highly rounded edges. B– cross section of columnal C– a column made of many columnals B A C

Cupulocrinus polydactylus
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Cupulocrinus polydactylus B A, B, C– the top of the calyx and the lower parts of the arms. A C

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Iocrinus subcrassus The column is characterized by pentalobate (five lobed) shape. C, D– cross section of various columnals. A B

Plicodendrocrinus casei
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Plicodendrocrinus casei The aboral cup (calyx) is characterized by having distinctive stellate (star-shaped) pattern of ridges. A– cross section of columnal B-- calyx B A

pseudoplanispiral shell
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Gastropods Kingdom Animalia Phylum Mollusca Class Gastropoda Clathrospira subconica Cyclonema Cyclonema bilix lata Cyrtolites ornatus Liospira vitruvia Loxoplocus bowdeni Sinuites cancellatus Unidentified #1 apex conch spire suture body whorl aperture planispiral shell conispiral shell pseudoplanispiral shell The gastropods, or snails, are extremely diverse inhabiting marine, fresh water and terrestrial environments. Their shell can coil in a conical (conispiral) or in in single plane (planispiral).

Clathrospira subconica
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Clathrospira subconica Medium sized and broadly turreted. The largest specimens illustrated here are about 3 cm in width. Conispirally coiled. B A C D

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Cyclonema A gastropod characterized by its fine costae that coil around the shell to 2.5 cm in width. 1 to 2.5 cm in height. Conispirally coiled. B– view showing aperture (opening in shell) C– detail showing characteristic fine costae C B A E D

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Cyclonema bilix lata This can be distinguished from other species of Cyclonema by its large size, height, and additional whorls. It also has a medial groove in the largest whorl. These two specimens are about 2.5 cm in height. Conispirally coiled. A B C

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Cyrtolites ornatus This species may belong to the Monoplacophoran class of mollusks instead of the Gastropoda. Cyrtolites is characterized by its large size, and distinct shell ornamentation. Planispirally coiled. C B A D

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Liospira vitruvia B A small gastropod, about 1 cm in diameter and 0.3 cm in height. Conispirally coiled, but not in a tall cone. C A

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Loxoplocus bowdeni Medium sized, high turreted form with a keel running around the shell. The internal molds of this species is common and usually do not show the keel. D shows the best example of the keel. Conispirally coiled. C B A D

Sinuites cancellatus B
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Sinuites cancellatus B A planispiral gastropod 1-4 cm in diameter. This species may belong to the class Monoplacophora instead of Gastropoda. C A D

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Unidentified #1 A small pseudoplanispiral gastropod with distinct ornamentation on its shell (shown in B). A B

Pelecypods Ambonychia robusta Anomalodonta gigantea Caritodens demissa
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Pelecypods Kingdom Animalia Phylum Mollusca Class Bivalvia Ambonychia robusta Anomalodonta gigantea Caritodens demissa Crytodontula umbonata Cycloconcha milleri Cymatonota typicalis Ischyrodonta elongata Modiolopsis posterior adductor muscle scar anterior adductor muscle scar right interior Dorsal view anterior pallial line umbo posterior anterior hinge growth line right valve left valve right exterior posterior This class includes the clams, scallops, mussels and oysters. Pelecypods have a right and left valve which usually separate after death unless the organism is buried alive. The valves are joined together via a hinge and held together by muscles inside the shell. If the valves are symmetrical (and usually they are not) they symmetry will be parallel to the hinge line and not perpendicular to it as in the brachiopods.

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Ambonychia robusta One of the most common pelecypods in the Cincinnatian ranging from 3-7 cm in length. This genus is distinguished from Anomalodonta by having much finer radiating costae. B– molds B A D C E

Anomalodonta gigantea
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Anomalodonta gigantea B This is a large pelecypod (as its species name implies) and is characterized by its very coarse costae. Size 7-9 cm in length. B– internal mold A C

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Caritodens demissa The distinctive characteristics of this pelecypod are its prominent concentric growth lines. This pelecypod is common and can be quite large ranging up to 7 cm in length. C B A E D

Crytodontula umbonata
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Crytodontula umbonata A medium to large pelecypod, 3-7 cm in length. Broad prominent beaks. A B C

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Cymatonota typicalis This pelecypod is characterized by its straight hinge line and lack of any muscle impressions. The shell is very thin and it is rarely seen. This specimen about 9 cm long. A B

Cycloconcha milleri A very small pelecypod, about 1 cm in length. A B
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Cycloconcha milleri A very small pelecypod, about 1 cm in length. A B

Ischyrodonta elongata
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Ischyrodonta elongata This species resembles Modiolopsis, but differs from it in the presence of a diagonal ridge (a groove in internal molds) that runs from the beak to the lower margin (shown nicely in Figure B). A B

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Modiolopsis (?) A medium to large pelecypod. This specimen is about 5 cm in length. B A C

juvenile (proximal) part
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Tentaculitoids Uncertain taxonomic affinity aperture Tentaculitoids are a group of extinct marine invertebrates whose taxonomic affinity is uncertain. They are usually small, and conical shaped. Sometimes their shells disarticulate and are found as small rings. Sometimes numerous shells can be found on the same bedding plane, suggesting mass mortalities of the animals. annulet ring adult (distal) part Tentaculites richmondensis (25 to 30 mm long) Tentaculites sterlingensis (10 to 15 mm long) juvenile (proximal) part apex

Tentaculites richmondensis
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Tentaculites richmondensis A Adult specimens are usually mm long and 2 to 3 mm wide at the aperture. The shell is often slightly curved. There are 20 to 30 rings in the adult. The rings are not as densely spaced as in Tentaculites sterlingensis.

Tentaculites sterlingensis
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Tentaculites sterlingensis A The adult specimen is 10 to 15 mm long. The rings are more densely packed than in Tentaculites richmondensis at 20 to 25 rings per 10 mm. B C

Trilobites Acidaspis cincinnatiensis Ceraurinus icarus
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Trilobites Kingdom Animalia Phylum Arthropoda Class Trilobita Acidaspis cincinnatiensis Ceraurinus icarus Flexicalymene meeki Isotelus gigas Isotelus maximus Tricopelta breviceps Rusophycus pudicum eye cephalon (head) glabella genal spine thorax axial lobe pygidium (tail) pleural lobe Trilobites were a bottom dwelling marine arthropod (like crabs), only known from fossils. They often molted as they grew, so their heads and “tails” are often found preserved rather than their entire body. Click here for a website on additional Cincinnatian trilobites.

Acidaspis cincinnatiensis
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Acidaspis cincinnatiensis A A small spiny trilobite which is covered with numerous tubercles. The photo shown is the part of the pygidium (tail) of a small specimen.

Ceraurinus icarus The pygidium of a small Ceraurinus. A Main Menu
Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Ceraurinus icarus A The pygidium of a small Ceraurinus.

Flexicalymene meeki C B E D A G F
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Flexicalymene meeki C Flexicalymene is the most common trilobite found in the Cincinnatian. Usually “heads” and “tails” are found because the trilobite molted, shedding its exoskeleton to grow larger in size. Complete specimens can be flat or enrolled. Size ranges from 2 mm up to 6 cm in length. Small enrolled specimens are common and usually “pea” sized as shown in figure B. B, D, F, G– enrolled specimens C– flat specimen E– cephalons or “heads” B E D A G F

Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Isotelus gigas B Isotelus is one of the largest genera of trilobites known. I. gigas has a sub-triangular shaped cephalon and pygidium and lacks the large genal spines of I. maximus. Specimens can be flat, or enrolled, as shown. A– the cephalon of an enrolled specimen B, C, D– views of the cephalon, thorax and pygidium of the same two specimens. A C D

Isotelus maximus B D E F C A
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Isotelus maximus B This is the state fossil of Ohio and the most common species of Isotelus. It reached sizes in excess of 50 cm! The pygidium and cephalon are more rounded than that of I. gigas. This trilobite possesses large genal spines which can often be found as broken pieces (E). A– pygidium of complete enrolled specimen B– complete specimen (on display at Caesar’s Creek State Park) C– cephalon of A, note short genal spine E– a broken genal spine D E F C A

Tricopelta breviceps B
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Tricopelta breviceps B A small trilobite, u to 3 cm in length. The eyes are large and the head is covered with numerous tubercles. A-D– various views of the same enrolled specimen. C A D

Mud with “hollow” dug by trilobite.
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Rusophycus pudicum Mud with “hollow” dug by trilobite. This is a trace fossil made by a trilobite. These are found on the underside of limestone layers. They were formed from the trilobite digging a hollow in mud which was later filled and covered by calcareous mud that turned into limestone. A– view from what was the bottom of the burrow. B– view from what would have been the side of the upside down burrow Hollow filled with carbonate mud that becomes limestone. This is the part of the rock that is found. A B

Instructions, Notes, and References
Main Menu Brachiopods Bryozoans Cephalopods Corals Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Exit Instructions, Notes, and References This is a PowerPoint program which can be run by clicking the forward () and backward () arrows on the keyboard. However, it may be more useful to click on the menu links at the top of each page or click on the many photo links to navigate your way through the program. A hand will appear above an active link as you drag the cursor across it. By clicking on you will go back to the last slide viewed. Clicking on will take you to the next slide in the sequence. You can also click anywhere on the page where there is not a link to get to the next slide. Genus and species names are always in italics. The first letter of the genus name will be capitalized. All the letters of a species name will be in lower case. For example, Flexicalymene meeki, a trilobite. To identify a fossil, look at each photo in the category carefully and compare the size of you specimen with those pictured. Look at the notes for helpful hints on distinguishing similar species from each other. This is not meant to be a comprehensive guide to all of the fossils found in the Cincinnatian of Ohio. Most of the specimens were collected by the author or his students in the Waynesville, Ohio area. The scale in all of the pictures is in millimeters. All photos are by John Whitmore using a Sony MVC FD73 Mavica. Two sources were used to identify the specimens: Cincinnati Fossils, edited by R.A. Davis, Cincinnati Museum Center, 1998. Fossils of Ohio, edited by Rodney M. Feldmann, Ohio Division of Geological Survey, Bulletin 70, 1996. It is not guaranteed that all specimens have been identified correctly, but every attempt was made to do so using the sources above.

Click here to exit Main Menu Brachiopods Bryozoans Cephalopods Corals
Crinoids Gastropods Pelecypods Tentaculitoids Trilobites Click here to exit

Identification Guide for Common Fossils from the Cincinnatian of Ohio

Similar presentations

Presentation on theme: "Identification Guide for Common Fossils from the Cincinnatian of Ohio"— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

Identification Guide for Common Fossils from the Cincinnatian of Ohio

Similar presentations

Presentation on theme: "Identification Guide for Common Fossils from the Cincinnatian of Ohio"— Presentation transcript:

Similar presentations

About project

Feedback