Palaeorhynchidae Temporal range: | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Carangiformes |
Superfamily: | Xiphioidea |
Family: | † Palaeorhynchidae Günther, 1880 |
Palaeorhynchidae is an extinct family of billfishes known from fossil remains. These fish are recognized for their distinctive elongated, bill-like snouts, a feature they share with modern billfishes such as swordfish and marlins. The Palaeorhynchidae lived during the early Eocene Epoch, and are considered an early lineage within the broader evolution of billfish-like species.
The family Palaeorhynchidae includes several genera of billfish, many of which exhibit features that suggest an early adaptation to the development of the long, spear-like rostrums seen in later groups of billfishes. These elongated bills served specialized feeding functions, possibly for hunting or slashing through hordes of smaller fishes, much like the behavior seen in modern swordfish. However, the specific ecological role of Palaeorhynchidae remains a topic of scientific study and debate.
Though they shared a similar morphology to modern billfishes, Palaeorhynchidae is not considered the direct ancestor of modern species. Instead, they represent an early branch in the evolutionary tree of billfishes, showcasing the evolutionary history before the rise of modern billfish families.
The fossil evidence for Palaeorhynchidae provides more insight on the diversity of marine life during the early eocene period sheds light on how billfishes evolved over millions of years and how their unique features, such as their bills and body shapes, may have developed in response to their marine environments and prey availability. The family Palaeorhynchidae ultimately became extinct, but it remains an important part of the history of early billfishes. [1] [2] [3] [4]
Marlins are fish from the family Istiophoridae, which includes 11 species.
The swordfish, also known as the broadbill in some countries, are large, highly migratory predatory fish characterized by a long, flat, pointed bill. They are a popular sport fish of the billfish category, though elusive. Swordfish are elongated, round-bodied, and lose all teeth and scales by adulthood. These fish are found widely in tropical and temperate parts of the Atlantic, Pacific, and Indian Oceans, and can typically be found from near the surface to a depth of 550 m (1,800 ft), and exceptionally up to depths of 2,234 m. They commonly reach 3 m (10 ft) in length, and the maximum reported is 4.55 m in length and 650 kg (1,430 lb) in weight.
The white marlin, also known as Atlantic white marlin, marlin, skilligalee, is a species of billfish that lives in the epipelagic zone of the tropical and subtropical Atlantic Ocean. They are found between the latitudes of 45° N and 45° S in waters deeper than 100 m. Even though white marlin are found in bodies of water that are deeper than 100 m they tend to stay near the surface. White marlin have been found near banks, shoals, and canyons, but they are not limited to those locations. They prefer warm surface temperatures greater than 22 °C.
The billfish are a group of saltwater predatory fish characterised by prominent pointed bills (rostra), and by their large size; some are longer than 4 m (13 ft). Extant billfish include sailfish and marlin, which make up the family Istiophoridae; and swordfish, sole member of the family Xiphiidae. They are often apex predators which feed on a wide variety of smaller fish, crustaceans and cephalopods. These two families are sometimes classified as belonging to the order Istiophoriformes, a group which originated around 71 million years ago in the Late Cretaceous, with the two families diverging around 15 million years ago in the Late Miocene. However, they are also classified as being closely related to the mackerels and tuna within the suborder Scombroidei of the order Perciformes. However, the 5th edition of the Fishes of the World does recognise the Istiophoriformes as a valid order, albeit including the Sphyraenidae, the barracudas.
Protosphyraena is a fossil genus of swordfish-like marine fish, that thrived worldwide during the Cretaceous period (Albian-Maastrichtian). Fossil remains of this taxon are mainly discovered in North America and Europe, and potential specimens are also known from Asia, Africa and Australia. Its fossils are best known from the Smoky Hill Member of the Niobrara Chalk Formation of Kansas.
Palaeotis is a genus of paleognath birds from the middle Eocene epoch of central Europe. One species is known, Palaeotis weigelti. The holotype specimen is a fossil tarsometatarsus and phalanx. Lambrect (1928) described it as an extinct bustard, and gave it its consequent name. After a suggestion by Storrs L. Olson, a review of the type specimen and the referral of several other fossils by Houde and Haubold (1987) concluded that Palaeotis is a palaeognath and assigned it to the same order as ostriches; the Struthioniformes. In 2021, it was considered a member of the family Paleotididae alongside Galligeranoides from the Early Eocene of France, which were found to be basal members of the Struthioniformes.
Blochius is an extinct genus of billfish from the Eocene. It is only known from the Monte Bolca deposits in Italy, and was likely restricted to shallow, tropical waters of the Tethys Ocean.
Stratodus is a genus of giant prehistoric aulopiform fish found in Cretaceous-aged marine strata of Kansas, Alabama, Morocco, Israel, and Niger, South Dakota, Jordan. It has also been found in the Tamaguélelt Formation of Mali, dating to the Lower Eocene, indicating that Stratodus survived the Cretaceous-Paleogene extinction event. This sleek fish has an upper jaw filled with multiple rows of tiny teeth and was the largest aulopiform, reaching 5 meters in length.
Asiatosuchus is an extinct genus of crocodyloid crocodilians that lived in Eurasia during the Paleogene. Many Paleogene crocodilians from Europe and Asia have been attributed to Asiatosuchus since the genus was named in 1940. These species have a generalized crocodilian morphology typified by flat, triangular skulls. The feature that traditionally united these species under the genus Asiatosuchus is a broad connection or symphysis between the two halves of the lower jaw. Recent studies of the evolutionary relationships of early crocodilians along with closer examinations of the morphology of fossil specimens suggest that only the first named species of Asiatosuchus, A. grangeri from the Eocene of Mongolia, belongs in the genus. Most species are now regarded as nomina dubia or "dubious names", meaning that their type specimens lack the unique anatomical features necessary to justify their classification as distinct species. Other species such as "A." germanicus and "A." depressifrons are still considered valid species, but they do not form an evolutionary grouping with A. grangeri that would warrant them being placed together in the genus Asiatosuchus.
Acestrus is an extinct genus of marine ray-finned fish that lived during the lower Eocene in Europe. It contains one species, A. ornatus from the London Clay, known from a single braincase. It is thought to possibly be closely allied with billfish based on the braincase morphology, although it remains uncertain whether it had the rostrum characteristic of billfishes. Some authorities have suggested blochiid affinities.
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.
Xiphiorhynchus is an extinct genus of prehistoric swordfish that lived from the Eocene until the Oligocene. Unlike the modern swordfish, both the upper and lower jaws of Xiphiorhynchus were extended into blade-like points.
Barbinae are a subfamily of fish included in the family Cyprinidae. The taxonomy for this group has not been entirely worked out as some genera historically considered within it are still considered incertae sedis with respect to being a member of the family, and may be included here, while others may be moved to other subfamilies.
Ocepeia is an extinct genus of afrotherian mammal that lived in present-day Morocco during the middle Paleocene epoch, approximately 60 million years ago. First named and described in 2001, the type species is O. daouiensis from the Selandian stage of Morocco's Ouled Abdoun Basin. A second, larger species, O. grandis, is known from the Thanetian, a slightly younger stage in the same area. In life, the two species are estimated to have weighed about 3.5 kg (7.7 lb) and 10 kg (22 lb), respectively, and are believed to have been specialized leaf-eaters. The fossil skulls of Ocepeia are the oldest known afrotherian skulls, and the best-known of any Paleocene mammal in Africa.
Septencoracias is an extinct genus of bird related to modern rollers and other Coraciiformes such as kingfishers, bee-eaters, motmots, and todies. It contains two species, Septencoracias morsensis described in 2016, and S. simillimus, which was named in 2024. It was found in the Fur Formation of Denmark, dating back to the Ypresian of the Lower Eocene Epoch, about 54 million years ago. Septencoracias is one of the earliest known members of Coraciiformes, lending insight into the earliest radiation of this group.
Of the twelve species of billfish, there are six species of Billfish in the Indian Ocean.
Pentanogmius is an extinct genus of sail-finned ray-finned fish that lived during the Late Cretaceous in what is now Europe and the United States. Five species are currently recognized, 2 from Cenomanian to Turonian Europe and 3 better known species from Coniacian to Campanian North America. The American species inhabited large areas of the Western Interior Seaway, with fossil finds indicating a range from Texas and Alabama in the south to Manitoba, Canada, in the north.
Tonsala is an extinct genus of Plotopteridae, a family of flightless seabird similar in biology with penguins, but more closely related to modern cormorants. The genus is known from terrains dated from the Late Oligocene of the State of Washington and Japan.
Phocavis is an extinct genus of flightless seabird, belonging to the family Plotopteridae, and distantly related with modern cormorants. Its fossils, found in the Keasey Formation in Oregon, are dated from the Late Eocene.
Hemingwaya is an extinct genus of billfish in the monotypic family Hemingwayidae that lived during the Eocene epoch, approximately 56 to 34 million years ago. Members of this family are characterized by their elongated, spear-like bills, a feature that defines modern billfish such as swordfish and marlins.