Ichthyodectidae
Encyclopedia
The family
Ichthyodectidae (literally "fish-biters") was a family
of marine actinopterygian
fish
. Sometimes classified in the primitive bony fish order
Pachycormiformes
, they are today generally regarded as members of the "bulldog fish" order Ichthyodectiformes in the far more advanced Osteoglossomorpha
. The type genus
is Ichthyodectes
, established by Edward Drinker Cope
in 1870.
They were most diverse throughout the Cretaceous
period, though Thrissops
fossils are known from the Oxfordian
-Kimmeridgian
boundary in the Late Jurassic
. Most ichthyodectids ranged between 1 and 5 meters (3–15 ft) in length. All known taxa were predators, feeding on smaller fish; in several cases, larger Ichthyodectidae preyed on smaller members of the family. Some species
had remarkably large teeth, though others, such as Gillicus arcuatus
, had small ones and sucked in their prey.
Basal or incertae sedis
Subfamily Saurodontinae
Subfamily Ichthyodectinae
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Ichthyodectidae (literally "fish-biters") was a family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of marine actinopterygian
Actinopterygii
The Actinopterygii or ray-finned fishes constitute a class or sub-class of the bony fishes.The ray-finned fishes are so called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines , as opposed to the fleshy, lobed fins that characterize...
fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
. Sometimes classified in the primitive bony fish order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Pachycormiformes
Pachycormiformes
Pachycormiformes is an extinct order of ray-finned fish known from Mesozoic deposits from Eurasia and the Americas. They were characterized by having serrated pectoral fins, reduced pelvic fins and a bony rostrum...
, they are today generally regarded as members of the "bulldog fish" order Ichthyodectiformes in the far more advanced Osteoglossomorpha
Osteoglossomorpha
Osteoglossomorpha is a group of bony fish in the Teleostei.-Notable members:A notable member is the Arapaima , the largest freshwater fish in South America and one of the very largest bony fishes alive. Other notable members include the bizarre freshwater elephantfishes .-Systematics:Most...
. The type genus
Type genus
In biological classification, a type genus is a representative genus, as with regard to a biological family. The term and concept is used much more often and much more formally in zoology than it is in botany, and the definition is dependent on the nomenclatural Code that applies:* In zoological...
is Ichthyodectes
Ichthyodectes
Ichthyodectes ctenodon was a 4-metre long ichthyodectid. It lived in the Western Interior Seaway during the late Cretaceous. It was closely related to the 4 to 6 metre long Xiphactinus audax, and the 2-metre long Gillicus arcuatus, and like other ichthyodectids, I. ctenodon is presumed to have...
, established by Edward Drinker Cope
Edward Drinker Cope
Edward Drinker Cope was an American paleontologist and comparative anatomist, as well as a noted herpetologist and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of nineteen...
in 1870.
They were most diverse throughout the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
period, though Thrissops
Thrissops
Thrissops is an extinct genus of teleost fish from the Jurassic and Cretaceous periods.Thrissops was a fast predatory fish about long, that fed on other bony fish. It had a streamlined body with a deeply cleft tail and only very small pelvic fins...
fossils are known from the Oxfordian
Oxfordian stage
The Oxfordian is, in the ICS' geologic timescale, the earliest age of the Late Jurassic epoch, or the lowest stage of the Upper Jurassic series. It spans the time between 161.2 ± 4 Ma and 155.7 ± 4 Ma...
-Kimmeridgian
Kimmeridgian
In the geologic timescale, the Kimmeridgian is an age or stage in the Late or Upper Jurassic epoch or series. It spans the time between 155.7 ± 4 Ma and 150.8 ± 4 Ma . The Kimmeridgian follows the Oxfordian and precedes the Tithonian....
boundary in the Late Jurassic
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 161.2 ± 4.0 to 145.5 ± 4.0 million years ago , which is preserved in Upper Jurassic strata. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age...
. Most ichthyodectids ranged between 1 and 5 meters (3–15 ft) in length. All known taxa were predators, feeding on smaller fish; in several cases, larger Ichthyodectidae preyed on smaller members of the family. Some species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
had remarkably large teeth, though others, such as Gillicus arcuatus
Gillicus arcuatus
Gillicus arcuatus was a relatively small, 2-metre long ichthyodectid fish that lived in the Western Interior Seaway, in what is now central North America, during the Late Cretaceous. Like its larger relative, Ichthyodectes ctenodon, G...
, had small ones and sucked in their prey.
Systematics
The basal phylogeny is very badly resolved, leading to many ichthyodectids that are simply known to be rather primitive, but where nothing certain can be said about their precise relationships.Basal or incertae sedis
Incertae sedis
, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...
- AsiamericanaAsiamericanaAsiamericana Asiamericana Asiamericana (AY-zha-MER-i-KAHN-a - (Greek: Asia meaning Asia and New Latin America meaning America) was a genus of theropod dinosaur which was named to recognize the occurrence of similar fossil teeth in Central Asia and North America. These regions once formed a...
? Nesov, 1995 - ChirocentritesChirocentritesChirocentrites is an extinct genus of Ichthyodectidae....
Hekel, 1849 - CladocyclusCladocyclusCladocyclus is an extinct genus of Ichthyodectidae.-References:* Fishes of the World by Joseph S. Nelson * Discovering Fossil Fishes by John Maisey and John G. Maisey...
Agassiz, 1841 - Cooyoo
- EubiodectesEubiodectesEubiodectes is an extinct genus of prehistoric bony fish that lived during the Cenomanian.-See also:* Prehistoric fish* List of prehistoric bony fish...
Hay, 1903 - Faugichthys Taverne & Chanet, 2000
- ThrissopsThrissopsThrissops is an extinct genus of teleost fish from the Jurassic and Cretaceous periods.Thrissops was a fast predatory fish about long, that fed on other bony fish. It had a streamlined body with a deeply cleft tail and only very small pelvic fins...
- Unamichthys Alvarado-Ortega, 2004
Subfamily Saurodontinae
- Prosaurodon Stewart, 1999
- SaurocephalusSaurocephalusSaurocephalus is an extinct genus of fishes within the family Saurodontidae Cope, 1871.Members of this family were teleostean fishes restricted to the upper Cretaceous...
Harlan, 1824 - SaurodonSaurodonSaurodon is an extinct genus of Ichthyodectid fish from the Cretaceous.Saurodon leanus is known to occur as early as the late Coniacian through the Santonian, in the Late Cretaceous.- Species :...
Subfamily Ichthyodectinae
- Gillicus (tentatively placed here)
- IchthyodectesIchthyodectesIchthyodectes ctenodon was a 4-metre long ichthyodectid. It lived in the Western Interior Seaway during the late Cretaceous. It was closely related to the 4 to 6 metre long Xiphactinus audax, and the 2-metre long Gillicus arcuatus, and like other ichthyodectids, I. ctenodon is presumed to have...
- Vallecillichthys Blanco & Cavin, 2003
- XiphactinusXiphactinusXiphactinus was a large, 4.5 to 6 m long predatory bony fish that lived in the Western Interior Sea, over what is now the middle of North America, during the Late Cretaceous. When alive, the fish would have resembled a gargantuan, fanged tarpon...