''Protosphyraena'' is a fossil

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

swordfish The swordfish (''Xiphias gladius''), also known as the broadbill in some countries, are large, highly migratory predatory fish characterized by a long, flat, pointed bill. They are the sole member of the Family (biology), family Xiphiidae. They ...

-like marine fish, that thrived worldwide during the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

period (

Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...

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 ...

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

remains of this

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

are mainly discovered in

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

and

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

, and potential specimens are also known from

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

and

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. Its fossils are best known from the Smoky Hill Member of the

Niobrara Chalk The Niobrara Formation , also called the Niobrara Chalk, is a Formation (stratigraphy), geologic formation in North America that was deposited between 87 and 82 million years ago during the Coniacian, Santonian, and Campanian stages of the La ...

Formation of Kansas (Late

Coniacian The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded by ...

-Early

Campanian The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

). ''Protosphyraena'' was a large fish, averaging in length. ''Protosphyraena'' shared the Cretaceous oceans with

aquatic Aquatic means relating to water; living in or near water or taking place in water; does not include groundwater, as "aquatic" implies an environment where plants and animals live. Aquatic(s) may also refer to: * Aquatic animal, either vertebrate ...

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

s, such as

mosasaurs Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Greek ' meaning 'lizard') are an extinct group of large aquatic reptiles within the family Mosasauridae that lived during the Late Cretaceous. Their first fossil remains were discovered in ...

and

plesiosaurs The Plesiosauria or plesiosaurs are an Order (biology), order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period (geology), Period, possibly in the Rhaetian st ...

, as well as with many other

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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 ...

predatory Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...

fish. The name ''Protosphyraena'' is a combination of the Greek word ''protos'' ("early") plus '' Sphyraena'', the genus name for

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 ...

, as

paleontologist Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geolo ...

s 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 The swordfish (''Xiphias gladius''), also known as the broadbill in some countries, are large, highly migratory predatory fish characterized by a long, flat, pointed bill. They are the sole member of the Family (biology), family Xiphiidae. They ...

, but belongs to the extinct family Pachycormidae.

History and taxonomy

As is the case with many

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

s discovered by 19th century paleontologists, the

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

of ''Protosphyraena'' has had a confusing history.

pectoral Pectoral may refer to: * The chest region and anything relating to it. * Pectoral cross, a cross worn on the chest * a decorative, usually jeweled version of a gorget * Pectoral (Ancient Egypt), a type of jewelry worn in ancient Egypt * Pectora ...

spines belonging to this taxon were first recognized in 1822, from chalk deposits in

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

, by

Gideon Mantell Gideon Algernon Mantell Membership of the Royal College of Surgeons, MRCS Fellow of the Royal Society, FRS (3 February 1790 – 10 November 1852) was an English obstetrician, geologist and paleontology, palaeontologist. His attempts to reconstr ...

, the physician and

geologist A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...

who also discovered the

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

Iguanodon ''Iguanodon'' ( ; meaning 'iguana-tooth'), named in 1825, is a genus of iguanodontian dinosaur. While many species found worldwide have been classified in the genus ''Iguanodon'', dating from the Late Jurassic to Early Cretaceous, Taxonomy (bi ...

''. In 1857, the fish was named ''Protosphyraena ferox'' by the renowned

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, p ...

naturalist Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...

and

Joseph Leidy Joseph Mellick Leidy (September 9, 1823 – April 30, 1891) was an American paleontologist, parasitologist and anatomist. Leidy was professor of anatomy at the University of Pennsylvania, later becoming a professor of natural history at Swarth ...

, based on Mantell's English finds. Earlier, Leidy had published an illustration of a ''Protosphyraena'' tooth from the Cretaceous-aged Navesink Formation of

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 ...

(Maastrichtian), but mistakenly identified it as having come from a dinosaur. During the 1870s, B. F. Mudge, a fossil collector supplying material to rival paleontologists

Edward Drinker Cope Edward Drinker Cope (July 28, 1840 – April 12, 1897) was an American zoologist, paleontology, paleontologist, comparative anatomy, comparative anatomist, herpetology, herpetologist, and ichthyology, ichthyologist. Born to a wealthy Quaker fam ...

and

Othniel Charles Marsh Othniel Charles Marsh (October 29, 1831 – March 18, 1899) was an American professor of paleontology. A prolific fossil collector, Marsh was one of the preeminent paleontologists of the nineteenth century. Among his legacies are the discovery or ...

, discovered a number of specimens of ''Protosphyraena'' in Niobrara exposures in Rooks and Ellis counties in

Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...

and sent them back east. Between 1873 and 1877, Cope renamed three species based on Mudge's specimens, all of which would eventually be recognized as belonging to the genus ''Protosphyraena'': ''Erisichte nitida'', ''"Portheus" gladius'', and ''"Pelecopterus" pernicciosus''. Between 1895 and 1903, paleontologists in America and England, including

Arthur Smith Woodward Sir Arthur Smith Woodward, FRS (23 May 1864 – 2 September 1944) was an English palaeontologist, known as a world expert in fossil fish. He also described the Piltdown Man fossils, which were later determined to be fraudulent. He is not rel ...

(1895), Loomis (1900), O. P. Hay (1903), in a series of important works, reviewed the genus, adding much to our understanding of this fish. Today, two species of ''Protosphyraena'' are recognized from the Niobrara Chalk of the western

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

: ''P. nitida'' and ''P. perniciosa''. An additional species, ''P. bentonianum'' was named by Albin Stewart in 1898, based on a specimen from the older Lincoln Member of the Greenhorn Limestone (Upper

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

). Perhaps the oldest remains of ''Protosphyraena'' in

have come from the upper beds of the Dakota Sandstone (middle

) in Russell County, Kansas (Everhart, 2005; p. 91). The species ''Australopachycormus hurleyi'' (meaning "southern ''Pachycormus''" and named after Tom Hurley, who discovered the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

specimen) was a long-billed pachycormid from the

Queensland, Australia Queensland ( , commonly abbreviated as Qld) is a state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Australia and New South Wales to the west, ...

, that was noted to be the earliest Cretaceous pachycormid from the Southern Hemisphere. It was already noted to closely resemble ''Protosphyraena'' during its description. Later studies have found ''Australopachycormus'' to be indistinguishable from ''Protosphyraena'', and they have thus been synonymized. The presence of ''Protosphyraena'' in Australia suggests that it had already achieved a very wide global distribution early on in its evolutionary history.

Anatomy

In its general body plan, ''Protosphyraena'' resembled a modern

sailfish The sailfish is one or two species of marine fish in the genus ''Istiophorus'', which belong to the family Istiophoridae ( marlins). They are predominantly blue to gray in colour and have a characteristically large dorsal fin known as the ...

, though it was smaller with a shorter

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit ** podium * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ...

, was somewhat less

hydrodynamic In physics, physical chemistry and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids – liquids and gases. It has several subdisciplines, including (the study of air and other gases in moti ...

, and adults possessed large blade-like teeth (adults of living swordfish species are toothless). Complete skeletons of ''Protosphyraena'' are relatively rare, but in parts of the Niobrara Chalk, the

Mooreville Chalk Formation The Mooreville Chalk is a geological formation in North America, within the U.S. states of Alabama and Mississippi, which were part of the subcontinent of Appalachia. The strata date back to the early Santonian to the early Campanian stage of th ...

Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

, and other

geological formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock expo ...

s, fragmentary specimens are quite common and most often include isolated teeth, the distinctive rostrum, and fragments of the long saw-edged pectoral fin first described by Mantell. Usually, portions of the skull and postcranial skeleton are found separately. This preservational bias can be explained by the fact that the skeleton of ''Protosphyraena'' was less

ossified Ossification (also called osteogenesis or bone mineralization) in bone remodeling is the process of laying down new bone material by cells named osteoblasts. It is synonymous with bone tissue formation. There are two processes resulting in t ...

than that of most bony fishes and tended to be torn apart by

scavenger Scavengers are animals that consume Corpse decomposition, dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a he ...

s or decay before burial and fossilization (Everhart, 2005; p. 93). Like most of the Cretaceous marine

fauna Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and '' funga'', respectively. Flora, fauna, funga and other forms of life are collectively ...

, ''Protosphyraena'' became extinct at the end of the

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

; the resemblance to living swordfish apparently results from

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last comm ...

Gallery

File:Protosphy01.jpg, Skull fossil File:Hay01.jpg, Holotype rostrum of ''Protosphyraena nitida'' (from Hay, 1903) File:Hay02.jpg, Holotype of ''Protosphyraena nitida'' (from Hay, 1903); portions of dentary, splenial, pectoral fin File:Protosphyraena fossils.jpg, Pectoral girdle of ''Protosphyraena perniciosa'' and other fossils

References

* *Cope, E. D. 1873. On two new species of Saurodontidae. ''Proceedings of the Academy of Natural Sciences of Philadelphia'' 25:337-339. *Cope, E. D. 1874. Review of the vertebrata of the Cretaceous period found west of the Mississippi River. ''U. S. Geolological Survey of the Territories, Bulletin'' 1(2):3-48. *Cope, E. D. 1875.
The Vertebrata of the Cretaceous Formations of the West
'. Report of the U. S. Geological Survey of the Territories. 2 (Washington, D.C.: Government Printing Office):302 pp. *Everhart, M. J. 2005. ''Oceans of Kansas: A Natural History of the Western Interior Sea''. Indiana University Press: 323 pp. * * * *Mantell, G. 1822. ''The fossils of the South Downs; or illustrations of the geology of Sussex''. London: Lupton Relfe. xiv + 327 pp. * *Woodward, A. S. 1895. ''Catalogue of the fossil fishes in the British Museum. Part 3''. British Museum of Natural History, London. pp. i-xliii, 1–544.

External links

at the ''Oceans of Kansas'' website. Includes detailed taxonomic history, life restorations, bibliography, many photos of fossil remains.
The most complete skeleton of ''Protosphyraena pernicosa'' yet found
on display at the Rocky Mountain Dinosaur Resource Center. Late Cretaceous fish of North America Cretaceous fish of Australia Pachycormiformes Prehistoric ray-finned fish genera Cretaceous bony fish Cretaceous fish of Europe Albian genus first appearances Maastrichtian genus extinctions Demopolis Chalk {{Cretaceous-fish-stub Taxa named by Joseph Leidy Fossil taxa described in 1857