Welcome to Catnapin's
Paleozoic Fish Fossil Gallery
Animalia, Chordata, Vertebrata
(Kingdom, Phylum, Subphylum)
Red text = needs information
*****************************************************************
Osteichthyes, Dipnoi, Sagenodontidae
(Class, Order, Family)
|
Sagenodus dialophus - "teeth" (parallel) Sagenodus fossatus - "teeth" (fanned) Common Name: lungfish Period: Lower Permian Location: ? Texas Collection: Dallas Museum of Natural History Collected by: ? Size: ? mm long |
|
|
Description: Dipnoans very early lungfish. They do not have actual teeth but instead boney plates. They first appear in Carboniferous and survive though the Cretaceous. During the Permian, they were widespread throughout the northern continents when they were still connected. It is thought that they were herbivores. It is debated whether they were freshwater, marine, or tolerant of both. |
|
*****************************************************************
Sharks
*****************************************************************
|
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. Xenacanths Xenacanths are freshwater, shark-like fish. Some may have grown nearly 12 feet long. Only a few species survived the Permian Extinction. Non-shark features: double cusp on each tooth root; a long spine attached to the back of the head; tail fin is straight, not upturned; pared fins with central axis. |
Chondrichthyes, Xenacanthida, Orthacanthidae
(Class, Order, Family)
|
Orthacanthus texensis - coprolite This species has not be confirmed Common Name: Zenacanth Period: Vale formation, Clear Fork group, lower Permian Location: north of Abilene Texas Collection: R. H. Tull Collected by: R. H. Tull Size: 70 mm long |
|
|
Description: coprolite from a large freshwater shark. The edge is spiraled, typical of sharks. |
|
Chondrichthyes, Xenacanthida, Orthacanthidae
(Class, Order, Family)
|
Orthacanthus texensis - jaw texture, teeth Common Name: Zenacanth Period: Permian Location: ? Texas Collection: Dallas Museum of Natural History Collected by: ? Size: ? mm long |
|
*****************************************************************
