Welcome to Catnapin's
Cretaceous Fish Fossil Gallery
Animalia, Chordata, Vertebrata
(Kingdom, Phylum, Subphylum)
Red text = needs information
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Sharks
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The fish class, Chondrichthyes, are sharks. Their skeletons are not made of bone but of cartilage. This makes fossilization difficult. Many extinct sharks are known only by their teeth because that is the only part that fossilizes well. And they had lots of teeth. Sharks don't have a single row of teeth. New ones constantly replace or push older ones to the side making the teeth row very wide. Some species had teeth covering the entire inside of their mouth. The skin of most sharks is covered in tiny plates, dermal denticles, making it feel like sandpaper. These plates are very similar to teeth. Scientists debate which came first in evolution. Did the dermal denticles migrate into the mouth or vise versa? Or did they evolve independently of the same minerals in the fish's body. As a group, sharks are very ancient. Their dermal denticles have been found in the Late Ordovician and Silurian. The oldest complete fish are Devonian. Most of the ancient sharks species became extinct at the end of the Permian then more through the Triassic when the group leading to current sharks started to evolve and become widespread in the Jurassic. |
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Chondrichthyes, Lamniformes, Cretoxyrhinidae
(Class, Order, Family)
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Cretoxyrhina mantelli Common Name: ? Period: Cretaceous Lower Eagle Ford Group, Tarrant Formation of North Texas Lower Eagle Ford Group, Lake Waco Formation of Central Texas Location: Coryell or Bell County Texas Collection: Don Brenholtz Size: ? |
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Description: This is a large shark grew up to 18 feet long. Many sizes of teeth filled most of the mouth. It could rip a mosasaur apart. It became extinct before the end of the Cretaceous, 90 mya. |
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Below are two possible species for the teeth that follow.
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Chondrichthyes, Lamniformes, Cretoxyrhinidae (Class, Order, Family) Leptostyrax macrorhiza Common Name: Mako or Mackerel Shark Period: Cretaceous Woodbine Group, Lewisville Formation of North Texas Woodbine Group, Pepper Formation of Central Texas Uppermost Washita Group, Del Rio Formation of Central Texas Uppermost Washita Group, Grayson Formation of North Texas Upper Washita Group, Pawpaw Formation of North Texas Upper Washita Group, Weno Formation of North Texas Lower Washita Group, Duck Creek Formation of North Texas |
Chondrichthyes, Lamniformes, Mitsukurinidae (Class, Order, Family) Scapanorhynchus raphiodon Common Name: goblin shark Period: Cretaceous Lower Austin Group, Basal Austin Formation of North Texas Upper Eagle Ford Group, Arcadia Park Formation, Kamp Ranch Member of North Texas
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? Common Name: ? Period: Cretaceous Location: Outside Big Bend State Park, Texas Collection: Don Brenholtz Size: ? |
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Description:? |
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? Common Name: ? Period: Cretaceous Location: Coryell or Bell County Texas Collection: Don Brenholtz Size: ? |
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Description:? |
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Chondrichthyes, ?, ?
(Class, Order, Family)
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? - shark centrum Period: Cretaceous Location: Coryell or Bell County Texas Collection: Don Brenholtz Size: ? |
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Description:? |
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Chondrichthyes, ?, ?
(Class, Order, Family)
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? - shark centrum Common Name: ? Period: Cretaceous Location: Coryell or Bell County Texas Collection: Don Brenholtz Size: ? |
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Description: |
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Chondrichthyes, ?, ?
(Class, Order, Family)
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Uranoplosus pychnodont Common Name: Pychnodont Period: Cretaceous Location: Coryell or Bell County Texas Collection: Don Brenholtz Size: ? |
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Description: This is a type of shark that had flat teeth used to crush shells. The inside of the sharks mouth was covered in these teeth like a mosaic. It may have been similar to a ray. |
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Chondrichthyes, Hybodontiformes, Ptychodontidae
(Class, Order, Family)
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Ptychodus decurrens Ptychodus polygyrus Common Name: ?
Period: Late Cretaceous, Upper Eagle Ford Group,
Kamp Ranch Member of the Arcadia Park Formation, North Texas Location: Coryell, Bell, Tarrant, or Dallas County Texas Collection: Don Brenholtz Size: ? |
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Description: This is a type of shark that had flat teeth used to crush shells. The inside of the sharks mouth was covered in these teeth like a mosaic. It may have been similar to a ray. They are called Hybodotid sharks because in some species their teeth have a smooth lump in the center of the cusp. |
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