Ischyodus
Encyclopedia
Ischyodus is an extinct genus of cartilaginous fish
belonging to the subclass Holocephali
, which includes the modern-day chimaera
s. Fossils are known from Europe (including Russia), North America, and New Zealand.
Ischyodus was virtually identical to the present-day chimaera Chimaera monstrosa
, which is found in the Atlantic Ocean
and Mediterranean Sea
. Just like C. monstrosa, Ischyodus had large eyes, a long whip-like tail, small lips, large pectoral fins and dorsal fin
, and a dorsal spike attached to the front of the dorsal fin. The spike probably served as a method of protection against predators, and may have been venom
ous, as it is in modern chimaeras.
Dental plates of at least two species, Ischyodus rayhaasi and Ischyodus dolloi, have been found at several sites in North Dakota
.
Chondrichthyes
Chondrichthyes or cartilaginous fishes are jawed fish with paired fins, paired nares, scales, two-chambered hearts, and skeletons made of cartilage rather than bone...
belonging to the subclass Holocephali
Holocephali
The subclass Holocephali is a taxon of cartilaginous fish, of which the order Chimaeriformes is the only surviving group.Holocephali has an extensive fossil record that starts during the Devonian period. However, most fossils are teeth, and the body forms of numerous species are not known, or, at...
, which includes the modern-day chimaera
Chimaera
Chimaeras are cartilaginous fish in the order Chimaeriformes, known informally as ghost sharks, ratfish , spookfish , or rabbitfishes...
s. Fossils are known from Europe (including Russia), North America, and New Zealand.
Ischyodus was virtually identical to the present-day chimaera Chimaera monstrosa
Chimaera monstrosa
Chimaera monstrosa, also known as the rabbit fish or rat fish, is a species of fish in the Chimaeridae family.-Anatomy and appearance:...
, which is found in the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
and Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
. Just like C. monstrosa, Ischyodus had large eyes, a long whip-like tail, small lips, large pectoral fins and dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
, and a dorsal spike attached to the front of the dorsal fin. The spike probably served as a method of protection against predators, and may have been venom
Venom
Venom is the general term referring to any variety of toxins used by certain types of animals that inject it into their victims by the means of a bite or a sting...
ous, as it is in modern chimaeras.
Dental plates of at least two species, Ischyodus rayhaasi and Ischyodus dolloi, have been found at several sites in North Dakota
North Dakota
North Dakota is a state located in the Midwestern region of the United States of America, along the Canadian border. The state is bordered by Canada to the north, Minnesota to the east, South Dakota to the south and Montana to the west. North Dakota is the 19th-largest state by area in the U.S....
.