Protosphyraena
Encyclopedia
Protosphyraena is a fossil genus
of swordfish
-like marine fish, that throve 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 (Late Coniacian
-Early Campanian
). Protosphyraena was a large fish, averaging 2-3 metres in length. Protosphyraena shared the Cretaceous oceans with aquatic
reptile
s, 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
.
As is the case with many fossil
vertebrate
s discovered by 19th century paleontologists, the taxonomy
of Protosphyraena has had a confusing history. Fossil
pectoral
spines belonging to this taxon were first recognized in 1822, from chalk deposits in England
, by Gideon Mantell
, the physician and geologist
who also discovered the dinosaur
Iguanodon
. In 1857, the fish was named Protosphyraena ferox by the renowned American
naturalist
and paleontologist, Joseph Leidy
, 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
(Maastrichtian), but mistakenly identified is as having come from a dinosaur. During the 1870s, B. F. Mudge, a fossil collector supplying material to rival paleontologists Edward Drinker Cope
and Othniel Charles Marsh
, discovered a number of specimens of Protosphyraena in Niobrara exposures in Rooks and Ellis counties in Kansas
and sent them back east. Between 1873 and 1877, Cope named three species of 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
(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
: 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
). Perhaps the oldest remains of Protosphyraena in North America
have come from the upper beds of the Dakota Sandstone (middle Cenomanian
) in Russell County, Kansas (Everhart, 2005; p. 91).
, though it was smaller with a shorter rostrum
, was somewhat less hydrodynamic, 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
of Alabama
, and other geological formations, 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 than that of most bony fishes and tended to be torn apart by scavenger
s or decay before burial and fossilization (Everhart, 2005; p. 93). Like most of the Cretaceous marine fauna
, Protosphyraena became extinct at the end of the Mesozoic
; the resemblance to living swordfish apparently results from convergent evolution
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of swordfish
Swordfish
Swordfish , also known as broadbill in some countries, are large, highly migratory, predatory fish characterized by a long, flat 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...
-like marine fish, that throve worldwide during the Upper 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 (Coniacian
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 89.3 ± 1 Ma and 85.8 ± 0.7 Ma...
-Maastrichtian
Maastrichtian
The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...
). Though fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
remains of this taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
have been found in both Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, it is perhaps best known from the Smoky Hill Member
Smoky Hill Chalk
The Smoky Hill Chalk Member of the Niobrara Chalk formation is a Cretaceous conservation Lagerstätte, or fossil rich geological formation, known primarily for its exceptionally well-preserved marine reptiles. The Smoky Hill Chalk Member is the uppermost of the two structural units of the Niobrara...
of the Niobrara Chalk Formation of Kansas (Late Coniacian
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 89.3 ± 1 Ma and 85.8 ± 0.7 Ma...
-Early Campanian
Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...
). Protosphyraena was a large fish, averaging 2-3 metres in length. Protosphyraena shared the Cretaceous oceans with aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
reptile
Reptile
Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
s, such as mosasaurs and plesiosaurs, as well as with many other 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...
of extinct predatory fish. The name Protosphyraena is a combination of the Greek word protos ("early") plus Sphyraena, the genus name for barracuda
Barracuda
The barracuda is a ray-finned fish known for its large size and fearsome appearance. Its body is long, fairly compressed, and covered with small, smooth scales. Some species could reach up to 1.8m in length and 30 cm in width...
, 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
Pachycormidae
Pachycormidae is an extinct family 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. Certain members of the group were large filter-feeding planktivores...
.
History and Taxonomy
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
s discovered by 19th century paleontologists, the taxonomy
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
of Protosphyraena has had a confusing history. Fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
pectoral
Pectoral
Pectoral may refer to:* Pectoral cross, a cross worn on the chest* a decorative, usually jeweled version of a gorget* Pectoral , often iconographic with hieroglyphs* Pectoralis major muscle, commonly referred to as "pectorals" or "pecs"...
spines belonging to this taxon were first recognized in 1822, from chalk deposits in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, by Gideon Mantell
Gideon Mantell
Gideon Algernon Mantell MRCS FRS was an English obstetrician, geologist and palaeontologist...
, the physician and geologist
Geologist
A geologist is a scientist who studies the solid and liquid matter that constitutes the Earth as well as the processes and history that has shaped it. Geologists usually engage in studying geology. Geologists, studying more of an applied science than a theoretical one, must approach Geology using...
who also discovered the dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
Iguanodon
Iguanodon
Iguanodon is a genus of ornithopod dinosaur that lived roughly halfway between the first of the swift bipedal hypsilophodontids and the ornithopods' culmination in the duck-billed dinosaurs...
. In 1857, the fish was named Protosphyraena ferox by the renowned American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
naturalist
Natural history
Natural history is the scientific research of plants or animals, leaning more towards observational rather than experimental methods of study, and encompasses more research published in magazines than in academic journals. Grouped among the natural sciences, natural history is the systematic study...
and paleontologist, Joseph Leidy
Joseph Leidy
Joseph Leidy was an American paleontologist.Leidy was professor of anatomy at the University of Pennsylvania, and later was a professor of natural history at Swarthmore College. His book Extinct Fauna of Dakota and Nebraska contained many species not previously described and many previously...
, 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
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
(Maastrichtian), but mistakenly identified is 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
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...
and Othniel Charles Marsh
Othniel Charles Marsh
Othniel Charles Marsh was an American paleontologist. Marsh was one of the preeminent scientists in the field; the discovery or description of dozens of news species and theories on the origins of birds are among his legacies.Born into a modest family, Marsh was able to afford higher education...
, discovered a number of specimens of Protosphyraena in Niobrara exposures in Rooks and Ellis counties in Kansas
Kansas
Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...
and sent them back east. Between 1873 and 1877, Cope named three species of 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
Arthur Smith Woodward
Sir Arthur Smith Woodward was an English palaeontologist.-Biography:Woodward was born in Macclesfield, Cheshire, England and was educated there and at Owens College, Manchester. He joined the staff of the Department of Geology at the Natural History Museum in 1882. He became assistant Keeper of...
(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
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
: 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
Cenomanian
The Cenomanian is, in the ICS' geological timescale the oldest or earliest age of the Late Cretaceous epoch or the lowest stage of the Upper Cretaceous series. An age is a unit of geochronology: it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding...
). Perhaps the oldest remains of Protosphyraena in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
have come from the upper beds of the Dakota Sandstone (middle Cenomanian
Cenomanian
The Cenomanian is, in the ICS' geological timescale the oldest or earliest age of the Late Cretaceous epoch or the lowest stage of the Upper Cretaceous series. An age is a unit of geochronology: it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding...
) in Russell County, Kansas (Everhart, 2005; p. 91).
Anatomy
In its general body plan, Protosphyraena resembled a modern sailfishSailfish
'Sailfish' are two species of fish in the genus Istiophorus, living in warmer sections of all the oceans of the world. They are predominately blue to gray in color and have a characteristic erectile dorsal fin known as a sail, which often stretches the entire length of the back...
, though it was smaller with a shorter rostrum
Rostrum (anatomy)
The term rostrum is used for a number of unrelated structures in different groups of animals:*In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes....
, was somewhat less hydrodynamic, 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
Mooreville Chalk Formation
The Mooreville Chalk Formation is a geological formation in North America, within the U.S. states of Alabama and Mississippi. The strata date back to the early Santonian to the early Campanian stage of the Late Cretaceous. The chalk was formed by pelagic sediments deposited along the eastern edge...
of Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
, and other geological formations, 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 than that of most bony fishes and tended to be torn apart by scavenger
Scavenger
Scavenging is both a carnivorous and herbivorous feeding behavior in which individual scavengers search out dead animal and dead plant biomass on which to feed. The eating of carrion from the same species is referred to as cannibalism. Scavengers play an important role in the ecosystem by...
s or decay before burial and fossilization (Everhart, 2005; p. 93). Like most of the Cretaceous marine fauna
Fauna
Fauna or faunæ is all of the animal life of any particular region or time. The corresponding term for plants is flora.Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess shale fauna"...
, Protosphyraena became extinct at the end of the Mesozoic
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
; the resemblance to living swordfish apparently results from convergent evolution
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
.
External links
- Protosphyraena: A Late Cretaceous "Swordfish" 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.
