''Saurocephalus'' (from , 'lizard' and 'head') is an extinct genus of

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

es within the family Saurodontidae.Maisey, J. G.1991. ''Santana Fossils, an Illustrated Atlas''. New Jersey, T.F.H. Publications Inc., 190–207. The genus was first described in 1824 and contains six or seven species, including the type species ''S. lanciformis''.Harlan, R. 1824. On a new fossil genus of the order Enalio Sauri, (of Conybeare). ''Journal of the Academy of Natural Sciences of Philadelphia''. Series 1, 3(pt. 2): 331-337. ''Saurocephalus'' first appeared during the early

Valanginian In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 137.05 ± 0.2 Ma and 132.6 ± 0.2 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretac ...

and continued on to the

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

, where it nearly went

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

.Kaddumi, H. F. 2009. Saurodontids (Ichthyodectiformes: Saurocephalus) of Harrana with a description of a new species from the late Maastrichtian

Muwaqqar Chalk Marl Formation The Muwaqqar Chalk-Marl Formation or Muwaqqar Formation is a Late Cretaceous (Maastrichtian) and early Paleogene-aged geological formation in Jordan, cropping out across the Jordanian Highlands from north to south. It is the geological formation c ...

. In: Fossils of the Harrana Fauna and the Adjacent Areas. ''Publications of the Eternal River Museum of Natural History'', Amman, pp 215-231. However, the recent discovery of ''S. lanciformis'' remains from the earliest

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

indicates that it just barely survived into the

Cenozoic The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...

. This would make it the last surviving ichthyodectiform. ''Saurocephalus'' is almost entirely represented by fragmentary specimens with the exception of a few complete specimens, such as a near-complete specimen of the species ''S. longicorpus'' from Jordan. The complete material from Jordan offered an extensive amount of valuable information about ''Saurocephalus''. With an elongate, torpedo-like body, ''Saurocephalus'' was extremely fast and it was probably a formidable open-water ambush predator. The morphology of its teeth and jaw structure suggests it was a

piscivore A piscivore () is a carnivorous animal that primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted repti ...

. The closely set very sharp, and firmly anchored teeth lined up along the upper and lower jaws acted together like sharp serrated scissors. The ventral extension of the upper jaw deep unto the sides of the lower jaw made the jaws perform like meat slicers. ''Saurocephalus'' was a powerful and ferocious predator with a powerful jaw capable of slicing and biting off large chunks of meat from its potential prey items - no doubt, fish was on top of the diet list. To process large prey, it would cut them into smaller, more manageable pieces using its large jaws and serrated teeth. A close modern analogue of ''Saurocephalus'' and to the matter, saurodontids, would be

barracuda A barracuda is a large, predatory, ray-finned, saltwater fish of the genus ''Sphyraena'', the only genus in the family Sphyraenidae, which was named by Constantine Samuel Rafinesque in 1815. It is found in tropical and subtropical oceans worldw ...

s ('' Sphyraena barracuda''), known to ambush, ram, and stun their prey using the strong anterior projection of the dentary. Although not as notably elongate, the overall body outline of barracudas is similar to ''Saurocephalus''.Bardack, D. and G. Sprinkle. 1969. Morphology and relationships of saurocephalid fishes. ''Fieldiana Geology'' 16(12):297-340. ''S. lanciformis'' fossils are known from the early

Danian The Danian is the oldest age or lowest stage of the Paleocene Epoch or Series, of the Paleogene Period or System, and of the Cenozoic Era or Erathem. The beginning of the Danian (and the end of the preceding Maastrichtian) is at the Cretac ...

of the

Hornerstown Formation The Hornerstown Formation is a latest Cretaceous to early Paleocene-aged geologic Formation (geology), formation in New Jersey. It preserves a variety of fossil remains, including those of dinosaurs, and contains direct evidence of the Mass morta ...

New Jersey New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...

, indicating that they at least briefly survived the Cretaceous-Paleogene extinction event. They appear to have persisted longer into the Danian than other Mesozoic fish that have their youngest records from the formation (''

Pseudocorax ''Pseudocorax'' is an extinct genus of mackerel sharks that lived during the Late Cretaceous. It contains six valid species that have been found in Europe, the Middle East, North Africa, and North America. It was formerly assigned to the family ...

'', ''

Ischyodus ''Ischyodus'' (from , 'power' and 'tooth') is an extinct genus of chimaera. It is the most diverse and long-lived chimaera genus, with over 39 species found worldwide spanning over 140 million years from the Middle Jurassic to the Miocene. Alm ...

'', '' Anomoeodus'', and ''

Enchodus ''Enchodus'' (from , 'spear' and 'tooth') is an extinct genus of aulopiformes, aulopiform Actinopterygii, ray-finned fish related to alepisaurus, lancetfish and lizardfish. Species of ''Enchodus'' flourished during the Late Cretaceous, where t ...

''). File:Saurocephalus vert.jpg, Vertebra File:Saurocephalus intermedius.jpg, Partial Skeleton File:Saurocephalus lanciformis.JPG, Jaws of ''S. lanciformis''

References

{{Taxonbar, from=Q7427564 Ichthyodectiformes Prehistoric ray-finned fish genera Cretaceous fish of North America Valanginian genus first appearances Paleocene genus extinctions Taxa named by Richard Harlan Fossil taxa described in 1824