Rajiformes is one of the four orders in the superorder Batoidea, flattened cartilaginous fishes related to sharks. Rajiforms are distinguished by the presence of greatly enlarged pectoral fins, which reach as far forward as the sides of the head, with a generally flattened body. The undulatory pectoral fin motion diagnostic to this taxon is known as rajiform locomotion. The eyes and spiracles are located on the upper surface of the head and the gill slits are on the underside of the body. Most species give birth to live young, although some lay eggs enclosed in a horny capsule.
Sclerorhynchus is an extinct genus of ganopristid sclerorhynchoid that lived during the Late Cretaceous. The genus Ganopristis is considered a junior synonym of Sclerorhynchus. It was a widespread genus, with fossils found in the Middle East, North Africa, Europe, and North America. While it had a long rostrum with large denticles similar to sawfishes and sawsharks, its closest living relatives are actually skates. Complete specimens of S. atavus show that its fin arrangement was similar to skates, with the pectoral and pelvic fins touching, both dorsal fins located behind the pelvic fins, and a reduced caudal fin.
Protosphyraena is a fossil genus of swordfish-like marine fish, that thrived worldwide during the Upper Cretaceous Period (Coniacian-Maastrichtian). Though fossil remains of this taxon have been found in both Europe and Asia, it is perhaps best known from the Smoky Hill Member of the Niobrara Chalk Formation of Kansas. Protosphyraena was a large fish, averaging 2–3 metres in length. Protosphyraena shared the Cretaceous oceans with aquatic reptiles, such as mosasaurs and plesiosaurs, as well as with many other species of extinct predatory fish. The name Protosphyraena is a combination of the Greek word protos ("early") plus Sphyraena, the genus name for barracuda, as paleontologists initially mistook Protosphyraena for an ancestral barracuda. Recent research shows that the genus Protosphyraena is not at all related to the true swordfish-family Xiphiidae, but belongs to the extinct family Pachycormidae.
Myliobatis is a genus of eagle rays in the family Myliobatidae.
Dalpiazia is an extinct genus of sclerorhynchid sawfish whose fossils are found in rocks dating from the Maastrichtian stage in mines in Jordan, Libya, Morocco and Syria. The type species D. stromeri was named by Checchia-Rispoli (1933) in honor of Ernst Stromer, and the holotype, a rostral tooth, was found in Tripolitania, Libya.
Rhombodus is a prehistoric genus of ray belonging to the family Rhombodontidae.
Ischyrhiza is an extinct genus of sclerorhynchoid ray from the Late Cretaceous (Cenomanian-Maastrichtian).
Cylindracanthus is an extinct, enigmatic genus of marine ray-finned fish with fossils known throughout North America, Europe, Asia and Africa from the Late Cretaceous to the late Eocene, with potential Oligocene records and a possible Miocene record also known. It is exclusively known from its distinctive partial remains, which are long cylindrical bony spines that are usually considered rostrum fragments, as well as some associated teeth. These spines are abundant & widespread throughout this timespan, and are useful indicators of a nearshore marine environment, but the taxonomic identity of the fish is still highly uncertain and debated.
Saurocephalus is an extinct genus of ray-finned fishes within the family Saurodontidae. The genus was first described in 1824 and contains six or seven species, including the type species S. lanciformis. Saurocephalus first appeared during the early Valanginian and continued on to the Maastrichtian, where it nearly went extinct. However, the recent discovery of S. lanciformis remains from the earliest Paleocene indicates that it just barely survived into the Cenozoic. This would make it the last surviving ichthyodectiform.
Harranahynchus is an extinct genus of schizorhizid sawskate that lived during the Late Cretaceous. It contains one valid species, Harranahynchus minutadens. It is known from relatively complete cranial and body fossils found in the Muwaqqar Chalk Marl Formation of Jordan, dating back to the late Maastrichtian. Its rostral denticles are extremely small and are arranged in batteries like its close relative Schizorhiza. It has an estimated length of around 2 m (6.6 ft).
Batoidea is a superorder of cartilaginous fishes, commonly known as rays. They and their close relatives, the sharks, compose the subclass Elasmobranchii. Rays are the largest group of cartilaginous fishes, with well over 600 species in 26 families. Rays are distinguished by their flattened bodies, enlarged pectoral fins that are fused to the head, and gill slits that are placed on their ventral surfaces.
Onchopristis is an extinct genus of sclerorhynchoid from the Cretaceous of North Africa, Europe, and North America. Its name is derived from the Ancient Greek ónkos and prístis. It contains two valid species, O. numida and O. dunklei, though some researchers argue that both may be considered a single taxon with variation in morphology caused by a wide geographical range. Specimens of Onchopristis have been discovered in coastal and fluvial deposits dated from the Barremian to the Maastrichtian age, making this genus one of the oldest and longest-lived sclerorhynchoid genera.
Micropristis is an extinct genus of ganopristid sclerorhynchoid that lived in the Middle East and Europe during the Late Cretaceous. The type specimen is known from the Cenomanian of Lebanon, and other specimens referrable to this genus have been found in Santonian-Campanian age rocks of Europe.
Ptychotrygon is a genus of sawfish-like ray whose fossils have been found worldwide from the Cretaceous period (Albian-Maastrichtian). Along with Ptychotrygonoides, Texatrygon, and Asflapristis, it is the member of the family Ptychotrygonidae within the suborder Sclerorhynchoidei.
Sclerorhynchoidei is an extinct suborder of rajiform rays that had long rostra with large denticles similar to sawfishes and sawsharks. This feature was convergently evolved, recently proposed as 'pristification', and their closest living relatives are actually skates. While they are often called "sawfishes", sawskates is a more accurate common name proposed in 2021 for sclerorhynchoids, which has been subsequently used by other researchers.
Atlanticopristis is an extinct genus of sclerorhynchid that lived during the Middle Cretaceous (Cenomanian) of what is now the Northeast Region of Brazil, between 100.5 and 93.9 million years ago. Fourteen fossil teeth from Atlanticopristis were found in the Alcântara Formation, and referred to the closely related Onchopristis in 2007; a redescription in 2008 by Brazilian paleontologists Manuel Medeiros and Agostinha Pereira assigned it to a new genus containing one species, Atlanticopristis equatorialis.
The Sao Khua sclerorhynchoid is an unnamed genus and species of sclerorhynchoid from the Early Cretaceous Sao Khua Formation in Thailand. It is known from the tip of a rostral denticle that is deposited in the Sirindhorn Museum as SM 2012-1-021. The denticle has a single barb similar to Onchopristis, Onchosaurus, and Pucapristis, but is distinguished from all other genera by having a row of enameloid "droplets" on each side. It is one of the earliest sclerorhynchoids, along with Celtipristis and Onchopristis which also appeared in the Barremian.
Propristis is an extinct genus of sawfish that lived from the Eocene to the Miocene. It contains two valid species, P. schweinfurthi and P. mayumbensis. It has been found in Egypt, Cabinda, Morocco, Qatar, Spain, the United Kingdom, and the United States. Isolated rostral denticles are the most common remains, but rostra have also been found.
Schizorhizidae is an extinct family of cartilaginous fish from the Late Cretaceous belonging to the suborder Sclerorhynchoidei. This family contains the genera Harranahynchus and Schizorhiza. It was originally named as a subfamily of Sclerorhynchidae, but was later raised to the rank of family.
Rarosaurus is an extinct genus of marine reptile that lived during the Late Cretaceous. It contains one valid species, R. singularis, and it was found in the Muwaqqar Chalk Marl Formation of Jordan.
