This timeline of ichthyosaur research is a chronological listing of events in the history of paleontology focused on the ichthyosauromorphs, a group of secondarily aquatic marine reptiles whose later members superficially resembled dolphins, sharks, or swordfish. Scientists have documented ichthyosaur fossils at least as far back as the late 17th century. At that time, a scholar named Edward Lhuyd published a book on British fossils that misattributed some ichthyosaur vertebrae to actual fishes;[1] their true nature was not recognized until the 19th century. In 1811, a boy named Joseph Anning discovered the first ichthyosaur fossils that would come to be scientifically recognized as such.[2] His sister Mary would later find the rest of its skeleton and would go on to become a respected fossil collector and paleontologist in her own right.[3]
Early researchers recognized ichthyosaurs as marine reptiles, but major aspects of their anatomy and behavior needed to be resolved. They were frequently portrayed as leaving the water to bask on rocks and with straight tails.[4] Although a bend in ichthyosaurs' tail vertebrae was seen from the earliest specimens, scholars assumed the bend reflected damage incurred to the animal's carcass after death. This bend was so common, however, that scholars eventually realized that it was natural and supported a shark-like tail fin.[5] Scientists came to realize that ichthyosaurs were too adapted to leave the water even to lay eggs. Evidence for live birth in ichthyosaurs dates back as far as 1846, when Chaning Pierce reported an apparent fossil Ichthyosaurus embryo to Sir Richard Owen.[6]
Ichthyosaur discoveries continued to be made into the 20th century. In 1928, Simeon Muller discovered the remains of 40 gigantic ichthyosaurs in Nevada. However, these remains would not be excavated until Charles Camp and Samuel Welles of Berkeley led an expedition for the purpose in the mid 1950s.[7] These fossils would take more than a decade to excavate, and the results of Camp's examination of the bones would not be published until a year after his 1975 death. These giant ichthyosaurs were named Shonisaurus popularis and their final resting place is now known as Berlin-Ichthyosaur state park.[8]
Other notable late 20th century advances in ichthyosaur research include the recognition of a new genus of ichthyosaur called Eurhinosaurus longirostris that had been misclassified as a species of Ichthyosaurus since 1854.[9] In 1986 Christopher McGowan would describe another, similar animal serendipitously discovered in England as Excalibosaurus, after King Arthur's mythicalsword.[9] The late 1990s and early 21st century would see scholarly debate regarding the cause of the ichthyosaurs' extinction, especially regarding the potential role played by competition with the mosasaurs which had evolved around the time.[10]
17th century
1699
Edward Lhuyd published a book called Lithophylacii Britannici Ichonographia about British fossils housed in Oxford's Ashmolean Museum. The book contained illustrations of unrecognized ichthyosaur vertebrae misidentified as belonging to fishes. 120 copies of the book were produced.[1]
19th century
1810s
Illustration of the ichthyosaur skull discovered by Joseph Anning. Everard Home, 1814The torso found by Mary Anning
1811
Joseph Anning discovered the first scientifically recognized ichthyosaur remains.[2]
1812
Mary Anning found the rest of the original ichthyosaur skeleton discovered by her brother Joseph.[2]
Everard Home changed his mind about the relationships of Ichthyosaurus. Instead of linking fishes with crocodiles, he concluded that it linked salamanders and lizards.[2] He tried to rename it Proteosaurus after the salamander genus Proteus, but his original name had priority and is still considered official.[11]
Mary Anning or a member of her family discovered a complete Ichthyosaurus skeleton in Lyme Regis. The find aroused widespread curiosity about ancient life throughout Britain.[2]
1824
The Reverend George Young discovered an ichthyosaur fossil in Whitby, Yorkshire. He also described the specimen, noting that it shared traits with crocodiles, fishes, and dolphins. Young speculated that ichthyosaurs might still be discovered alive as more of the world's seas and oceans are explored.[12]
Henry de la Beche illustrated a work titled "Duria Antiquior", meaning "Ancient Dorset" for fossil hunter Mary Anning. This work, which prominently features plesiosaurs, has been regarded as the first attempt to accurately reconstruct the Mesozoic world through an artistic medium.[13]
1834
Thomas W. Hawkins published a book titled Memoirs of Ichthyosauri and Plesiosauri. He sold it in subscription format for L2.10, an exorbitantly high price for the period.[14] The book included illustrations by landscape painter John Samuelson Templeton, although many of these inaccurately portray ichthyosaurs with straight tails and leaving the water to bask on rocks.[4]
1840s
1840
Owen described the new species "Ichthyosaurus" acutirostris.
Chaning Pearce discovered that a specimen of Ichthyosaurus communis contained the skeleton of another, tiny I. communis partially protruding from the larger individual's pelvis. After discussing the fossil with Sir Richard Owen, Pearce concluded that the specimen was a female killed and preserved in the act of giving birth.[6]
Gideon Mantell described the new species Ichthyosaurus longirostris based on fossil found in Whitby, Yorkshire. Its upper jaw was so much longer than its lower jaw that it resembled a swordfish.[9]
Quenstedt described the species that would later become known as Contectopalatus atavus.
1853
Henry Coles reported that ichthyosaurs were covered by scales resembling tiny hairs or spines. However, these supposed scales were actually hooklets from the tentacles of the prehistoric cephalopods the ichthyosaur had eaten.[15]
Harry Govier Seeley published an argument in favor of live birth in ichthyosaurs. Seeley noted that many ichthyosaur specimens from Britain and Germany contained miniature ichthyosaur skeletons inside them. While some researchers interpreted these remains as fossil stomach contents, Seeley observed that the smaller skeletons tend to be located too near the rear of the animal to be stomach contents. Instead, he interpreted the small skeletons as fetuses and the larger ones as pregnant females.[19]
1881
Owen described the species Ichthyosaurus breviceps .
1886
Bassani described the species that would later come to be known as Mixosaurus cornalianus.
J. C. Merriam named the new species Shastasaurus alexandrae after Annie Alexander, the wealthy fossil enthusiast who financed much of his research and founded the Museum of Paleontology at Berkeley.[23] He also described the species that would later come to be known as Californosaurus perrini.
J. C. Merriam discovered the unusual remains of an animal with short jaws and button-shaped teeth inNevada. He thought it was the first member of a new group of reptiles related to placodonts or rhynchosaurs but it would actually come to be recognized as ichthyosaurian and described as the genus Omphalosaurus.[25]
1908
Broili described the species that would later come to be known as Platypterygius platydactylus.
1909
Abel erected the genus Eurhinosaurus for the species Ichthyosaurus longirostris.[26]
Some putative ichthyosaur limb bones were found in Spitsbergen. Carl Wiman would later refer these remains to the species Omphalosaurus nevadanus.[25] Wiman also described the new genus and species Pessopteryx nisseri as well as the species that would one day be known as Isfjordosaurus minor.
Andrews speculated that since many specimens of Ophthalmosaurus are toothless that it may have fed via suction feeding on soft foods like squid.[27]
Huene described the new species Stenopterygius uniter as well as the species that would later become known as Temnodontosaurus nuertingensis .
1934
The most complete known ichthyosaur specimen from Australia, a Platypterygius was discovered in Queensland. Despite not being fully grown it was 18 feet in length.[17]
Alfred Romer noted that Jurassic ichthyosaurs were so highly specialized for aquatic life that their anatomy exhibited no sign of descent from any known terrestrial reptile group.[31]
1950s
A Stenopterygius skeleton from Holzmaden
1951
Willy Ley, a German zoologist, observed that more than two hundred ichthyosaur specimens were being recovered from Holzmaden annually.[18]
1954
Charles Camp and Samuel Welles of Berkeley lead the excavation of the gigantic ichthyosaur fossils discovered by Simeon Muller in the 20s. They estimated their body length to be 50 feet, which is roughly as large as a modern humpback whale.[7]
1956
Whitear reported brown pigmentation preserved in an ichthyosaur fossil.[32]
Camp's ichthyosaur excavation in Nevada ceased.[33]
Not far from Stowbridge in Norfolk, workers serendipitously discovered a large partial ichthyosaur skeleton while digging a drainage channel. The specimen was later thought to belong to the genus Ophthalmosaurus.[29]
McGowan argued that the narrow-finned longipinnate and the broad-finned latipinnate ichthyosaurs could be distinguished based on features of their skulls.[35]
McGowan described the cranial anatomy of Ichthyosaurus. He observed that it had a very large brain for a reptile. He interpreted the animal's large cerebellum as suggestive of highly coordinated bodily movements. He also noted that its large corpus striatum implied that it had a sophisticated repertoire of instinctive behaviors.[15] He speculated that social and parental behavior may have been among them.[36] By contrast, the lagena of Ichthyosaurus was small, suggesting that ichthyosaurs had weak sense of hearing.[37]
McGowan observed that the eyes of the supposed Ophthalmosaurus discovered in Norfolk during 1950s were too small for the animal to be referred to that genus and reclassified it in a new one: Grendelius.[29] He also described the species that would later come to be known as Brachypterygius mordax.
1978
Shikama, Kamei and Murata described the new genus and species Utatsusaurus hataii.
1979
McGowan observed that more ichthyosaur remains have been found in the Early Jurassic strata of southern Germany than anywhere else in the world.[18] He also speculated that in life most ichthyosaurs' biogeographic ranges would be as wide as those of modern whales and dolphins. McGowan attributed the narrow ranges of most known ichthyosaur species to an artifact of the fossil record, since paleontologists can only recover fossils from accessible exposures of sedimentary rocks formed in settings conducive to fossilization, which may not correspond to the complete life range of a given species.[39] He also rejected his own previous conclusion that latipinnate and longipinnate ichthyosaurs could be distinguished based on features of the skull and expressed doubt about the validity of the latipinnate-longipinnate dichotomy altogether.[35]
1980s
Shonisaurus fossils on exhibit at Berlin-Ichthyosaur State Park
1980
Joseph Gregory published the rest of his late friend Charles Camp's research on the ichthyosaurs of Berlin-Ichthyosaur State Park. This publication contained a reconstruction of Shonisaurus portraying as a long-skulled long-finned animal with an unusually deep "pot belly".[38]
1983
Angela Kirton reported the presence of teeth in skulls attributable to Ophthalmosaurus from England. The toothlessness of many adult skulls suggest that either Ophthalmosaurus lost its teeth as it aged or the teeth were only loosely attached and prone to falling out after death.[27]
1984
Wade observed that the longest digit in the flipper of Platypterygius was made up of a series of 30 bones.[35]
Fossils of an unusual ichthyosaur whose upper jaw was much longer than its lower jaw were found.[40]
1985
Skeletal mount of Ophthalmosaurus
An adult Ichthyosaurus communis specimen was found with a tiny associated embryo of the same species in Kilve, Somerset.[41]
A man named Bernd Neubig discovered an ichthyosaur skeleton during construction of a railroad in Karlstadt, Germany. The specimen was the most complete ichthyosaur discovered in that region of the country.[38]
Gasparini reported the first scientifically documented ichthyosaur remains from Argentina. He referred the Argentine ichthyosaur to the genus Ophthalmosaurus.[42]
Otschev and Efimov described the new species Platypterygius birjukovi.
1986
Christopher McGowan began leading a series of expeditions to Williston Lake, British Columbia, culminating in the discovery of the most complete known skeleton of Shastasaurus, which also served as the type specimen of a new species that would later be described in 1994.[43]
German paleontologist Jurgen Reiss speculated that ichthyosaurs swam using their front flippers the way modern penguins do rather than propelling themselves with their tail flukes.[44]
McGowan named the ichthyosaur with an unusually long, protruding upper jaw from Somerset Excalibosaurus, because it was found in the same general region where the legendary King Arthur obtained his sword.[40]
Massare and Callaway described a pregnant Mixosaurus specimen discovered in the Alps near the border between Switzerland and Italy. The specimen represented the oldest known evidence for live birth in ichthyosaurs.[45]
Three specimens attributable to a new Triassic ichthyosaur were discovered near Phattalung, Thailand by a man named Chongpan Chonglakmani.[46]
1989
Skeleton of Mixosaurus
In Dorset, England, a new specimen of Grendelius was discovered. However, when Christoper McGowan studied this new specimen he realized that while distinct from Ophthalmosaurus, Grendelius was apparently the same as the previously named genus Brachypterygius and the names were synonymized.[29]
McGowan observed that many Leptonectes specimens have somewhat protruding upper jaws.[47]
Remains of a Triassic ichthyosaur were discovered in Sonora, Mexico.[48]
Callaway and Massare regarded the genus Phalarodon as a nomen dubium.[49]
A tour guide describes Shonisaurus at Berlin-Ichthyosaur State Park
1990
Bradley Kosch of Berlin-Ichthyosaur State Park criticized Camp's 1980 reconstruction of the park's famous Shonisaurus popularis as having too short a backbone and overly deep ribs, responsible for its supposedly deep pot belly. He noted that the illustration differed from both the text of Camp's published description and his own private field notes.[38]
Stephen Jay Gould published an article about the tail bend in ichthyosaurs.[5]
De Buffrenil and Mazin found a woven texture in the bones of Ichthyosaurus, Omphalosaurus, and Stenopterygius. This texture is found only in the bones of quickly growing animals, suggesting that ichthyosaurs had high metabolic rates and may even have been warm blooded.[50]
Massare and Callaway observed that Triassic ichthyosaurs had more elongated body plans than their Jurassic successors.[46]
1991
An archaeologist named Keary Walde discovered large fossil bones near the Sikanni Chief River. He reported his discovery to the Royal Tyrell Museum.[30] The museum's curator, Elizabeth Nicholls, was also a respected marine reptile researcher, visited the site.Skeletal reconstruction of a Stenopterygius with young partially evacuated from the birth canal. These specimens may not reflect the preservation of mothers in the act of giving birth, but deceased feti being expelled from her by pressure resulting from gas build up in her bloating carcass. She was astonished to realize that the bones discovered by Walde were the remains of an ichthyosaur roughly 75 feet long, one and a half times as big as the largest known ichthyosaur at the time.[51]
McGowan argued that ichthyosaur fossils with new-born remains protruding from the birth canal don't imply that the mother died giving birth. Instead, they could be expelled from an already dead mother by the pressure of gas-build up as her rotting carcass bloated. An example of this in modern marine life was documented where the carcasses of beached false killer whales were given a shallow burial. Several months later, the pregnant females' fetuses had been partly expelled.[18] He also observed that roughly 35 ichthyosaur specimens a year were still being recovered from Holzmaden.[52] He suggested that at least some ichthyosaurs may have been warm-blooded and swift swimming like modern tuna due to their similar body plans.[50] He also noted that even if they weren't warm blooded their large body mass would help maintain stable body temperatures.[53]
Lingham-Soliar referred to the swimming style of advanced ichthyosaurs whose body remained stiff while large muscles powered the tail's swimming stroke as "axial oscillation".[54]
Mazin and others described the new genus and species Thaisaurus chonglakmanii.
1992
Field work on behalf of Alberta's Royal Tyrell Museum began in the Pink Mountains of British Columbia 60 miles north of where Christopher McGowan's field work was conducted. The Royal Tyrell researchers would discover Late Triassic ichthyosaur remains in the sediments of the Pardonet Formation.[30]
Close-up photograph of a Stenopterygius embryo
Judy Massare proposed an explanation for the high percentage of pregnant Stenopterygius at Holzmaden. She speculated that the area was used as a breeding ground, the way whales congregate to give birth in areas of shallow water today. The coordination of a large number of births at the same time and place would increase the young's chances of survival because there would be too many for the local predator population to eat. Massare suggested that another ichthyosaur genus, Leptopterygius (now known as Leptonectes), was one such local predator that may have fed on vulnerable young ichthyosaurs.[52]
Nathalie Bardet dismissed claims of ichthyosaur fossils from rocks of more recent age than the Cenomanian. She also discussed possible causes for the extinction of the ichthyosaurs. She expressed doubt that ichthyosaurs were replaced by mosasaurs because they would not be in direct competition with each other. Instead she posited a connection to an extinction event that affected cephalopods at the boundary between the Cenomanian and Turonian ages. She proposed that the disappearance of these many cephalopod species may have deprived ichthyosaurs of their food source and caused their extinction.[55]
1993
Charles Deeming and others published a paper on the 1985 ichthyosaur embryo discovered in Somerset. They observed that many pregnant ichthyosaur specimens contain fetuses oriented head-first toward the birth canal even though they were probably born tail-first as a precaution to prevent drowning. This suggests that there may have been complications during the pregnancy, like the fetus being too large to pass through the birth canal. If the decomposing fetus remained trapped in the mother, it would very likely kill her.[56]
Jennifer Hogler re-examined the tails of the early large ichthyosaurs Cymbospondylus and Shonisaurus, finding the wedge-shaped vertebrae that form the tail-bend that composes the tail fluke. This find contradicted the widespread idea that these early ichthyosaurs had straight tails and therefore lacked well-developed flukes.[57]
McGowan described the species that would later come to be known as Leptonectes solei.
1994
Axel Hungerbuhler bemoaned the taxonomic confusion caused by German geologist Friedrich Quenstedt's early research on the ichthyosaurs at Holzmaden. He attributed the bulk of this confusion to Quenstedt's unorthodox naming practices, which often exceeded the two-named binomials of standard biological nomenclature to consist of three or four names. Further, the fossils themselves were poorly organized and many of the type specimens he founded species on were unlabeled. Hungerbuhler named two new species of his own: Stenopterygius cuniceps and S. macrophasma.[58]
Christopher McGowan named the new species of Shastasaurus discovered in British Columbia S. neoscapularis.[43] He also reviewed the species previously referred to the genus, finding many of them to be dubious, like S. altus, S. careyi, S. carinthiacus, and S. osmonti. However, two previously described species, the type, S. pacificus, and the referred species S. alexandrae were found to be valid. He criticized Merriam for oversplitting Shastasaurus because most of the resulting names were useless and mislead the paleontological community into thinking that the genus was better understood than it really was.[30]
Bardet and others reported Platypterygius fossils from late Cenomanian rocks in Bavaria. These were the remains latest known ichthyosaurs.[55]
Fernández described the species that would later come to be known as Stenopterygius cayi.
1995
January: A man named Chris Moore discovered much of the front half of an ichthyosaur skeleton in the Belemnite Marls of Seatown, Dorset. The specimen was a juvenile of a new Leptopterygius species, named L. moorei after Moore.[59] In life, the specimen was probably about 8 feet long.[39]
Skeleton of Mixosaurus
McGowan renamed the ichthyosaur genus Leptopterygius to Leptonectes.[52] He also synonymized Leptopterygius with Temnodontosaurus.[52] He also described the new genus and species Hudsonelpidia brevirostris.
Martill claimed that despite an abundance of ichthyosaur specimens with preserved soft tissue, there was no evidence that ichthyosaur skin was covered in scales.[15]
Tichy described the new species Omphalosaurus wolfi.
Motani and others argued that sharks are the best modern analogues for ichthyosaurs because of their similar body plans.[54]
McGowan reported the serendipitous discovery of evidence for a new giant ichthyosaur species in a museum collection. He was studying the ichthyosaur fossils curated by the National Academy of Sciences in Philadelphia. One Early Jurassic bone catalogued as a part of a shoulder (the coracoid) he recognized as actually being a gigantic skull bone (the quadrate). The misidentification was probably due to the quadrate's exceptionally large size as the coracoid is generally one of the larger bones in the ichthyosaur body.[60] The implication of such a large quadrate being found was the existence a previously unknown ichthyosaur of similar or greater size to Shonisaurus itself. In life this animal may have been more than 50 feet long.[42] He also described the new genus Leptonectes as well as the species that would later come to be known as Macgowania janiceps.
Motani, You, and McGowan observed that the primitive ichthyosaur Chensaurus had had a relatively large number of vertebrae. This suggests that it swam in an eel-like fashion. The researchers interpreted the course of ichthyosaur evolution as starting with an eel-like body plan, transitioning to a jack-like body plan, and reaching its culmination in a tuna-like body plan.[61]
Ryosuke Motani completed his doctoral dissertation: "Phylogeny of the Ichthyosauria with Special Reference to Triassic Forms".
Callaway argued that it was inaccurate to refer to ichthyosaurs as ichthyopterygians.[16]
Callaway examined the mixosaurid fossils housed at the natural history museum in Zürich.[22] He regarded only two species of Mixosaurus to be valid; M. cornalianus and M. atavus. He regarded M. maotaiensis, M. natans, and M. nordeskioeldii as junior synonyms of those species. He also regarded several species in the genus Phalarodon as synonymous with the two valid Mixosaurus species.[62]
Martin Sander of the Institute for Paleontology in Bonn named the ichthyosaur found in Karlstadt, Germany Shastasaurus neubigi in honor of its discoverer. The specimen originated in the Muschelkalk, which was deposited in a shallow sea. Because the waters were so shallow and large ichthyosaurs are so infrequently found in the Muschelkalk Sander speculated that the ichthyosaur entered the region where it would later fossilize by accident in a deviation from the normal range of the species.[38]
Motani, Minoura, and Ando published a discussion of the ichthyosaur Utatsusaurus. They noted its primitive position in the ichthyosaur family tree and the same number of vertebrae in the front part of its body as modern catsharks. They interpreted Utatsusaurus as a maneuverable shallow water predator that swam with eel-like undulations along most of its body length.[63]
Artist's restoration of Eurhinosaurus
Maisch named the family Leptonectidae for a clade including Eurhinosaurus, Excalibosaurus, and Leptonectes. Distinguishing traits of the family include their large eyes, long flippers consisting of three or four main "digits", and their long over-biting snouts.[39]
Maisch and Matzke erected the genus Wimanius. The generic name honored Carl Wiman, who performed notable research on Triassic ichthyosaurs.[49] They also named the species Wimanius odontopalatus.
Maisch and Matzke described the new genus Contectopalatus. It had a high crest running the midlength of its cranium for jaw muscle attachment giving it a powerful bite. It also would have been about 16 feet long in life, making it twice as long as any previously discovered mixosaurid.[25]
Maisch erected the genus Suevoleviathan to house the species Leptopterygius disinteger.[49]
Darren Naish debunked the 1986 claim by Jurgen Riess that ichthyosaurs swam with their front flippers rather than their tail flukes. He concluded "if an animal has a propulsive surface on the end of its tail, it uses it."[64]
Ryosuke Motani published a phylogeny of the ichthyosaurs. Motani regarded Thaisaurus as "incertae sedis" due to its pronounced similarity to Chaohusaurus and how little was known about its fossils.[46] He also erected two new genera, Macgowania (named in honor of McGowan) and Isfjordosaurus (named after Isfjord, Spitsbergen).[20]
The expedition to the Sikanni Chief River, British Columbia led by Elizabeth Nicholls of the Royal Tyrell Museum excavated the animal's 18 foot long skull, which had to be split into pieces for removal. These pieces were so heavy a cargo helicopter was needed to transport them. The largest weighed 8,860 lbs.[7]
McGowan and Motani reported the results of their re-examination of the Shonisaurus specimens described by Camp from Berlin-Ichthyosaur state park. They concluded that of the three species Camp described from among the remains, only the type and most abundant species S. popularis was valid. The other two species he named, S. silberlingi and S. mulleri, were merely junior synonyms of S. popularis.[38]
Motani, Rothschild, and Wahl found that Temnodontosaurus had eyes up to 10 inches in diameter, the largest known of any animal.[29]
Lingham-Soliar proposed a model for ichthyosaur extinction whereby the evolution of fishes capable of greater swimming speeds during the Cretaceous favored ambush predators like plesiosaurs and the newly evolved mosasaurs over the ichthyosaurs, who succumbed to the competition.[65]
McGowan and Milner described the new species Leptonectes moorei.
Efimov described the new genus and species Undorosaurus gorodischensis. Efimov also described the species that would later come to be known as Ophthalmosaurus yasikovi.
An article about ichthyosaurs called "Dinodolphin" by Kate Douglas was published in New Scientist magazine.[66]
September
Rothschild, Motani, and Wahl presented an abstract to a meeting of the Society for Vertebrate Paleontology.[67] There they reported evidence that some Ophthalmosaurus suffered from the bends.[68]
Ryosuke Motani published an article on ichthyosaurs in Scientific American that documented the discovery of Utatsusaurus.[69]
Swiss watch maker Rolex honored Elizabeth Nicholls as a Rolex Laureate and bestowed on her a $100,000 stipend, covering much of the expenses generated by her field work.[7]
Sander expressed doubt as to whether or not Omphalosaurus was really an ichthyosaur. He also cast doubt on the idea that the limb bones from Spitsbergen referred to the genus by Carl Wiman actually belonged to the same kind of animal as the jaws discovered by J. C. Merriam that served as its type specimen.[25]
Maisch and Matzke erected the new genus Callawayia for the species Shastasaurus neoscapularis.[70] They also erected the new genus Phantomosaurus.
Nathalie Bardet and Marta Fernandez erected the new genus Aegirosaurus to house the species Ichthyosaurus leptospondylus. This was first new ichthyosaur to be described from the Solnhofen lithographic limestone in over 50 years prior to its naming.[24] The type specimen preserved extensive soft tissue traces. Bardet and Fernandez reported the presence of tiny scales covering the animal.[71] They disagreed with Martill, who claimed in 1995 that no evidence of a scaley covering existed in ichthyosaurs.[15]
2001
Skeleton of Mixosaurus
Maisch and Matzke recognized the genus Phalarodon as diagnostic rather than dubious.[49] They referred the species "Mixsaurus" major of the German Muschelkalk to that genus, and noted that this represented the first report of Phalarodon in that locality.[72]
Nicholls and Manabe erected the new genus Metashastasaurus for the species Shastasaurus neoscapularis.[73] However, since the genus Callawayia had already been named for this species by Maisch and Matzke it was never accepted as valid by the scientific community. Nicholls and Manabe also reported that since field work began in the Pardonet Formation of British Columbia's Pink Mountains, 65 ichthyosaur specimens had been recovered.[30]
Orndorff and others interpreted the burial site of the famous ichthyosaurs of Berlin-Ichthyosaur State Park as a deep ocean shelf rather than a shallow coastal area. They also proposed a new reinterpretation of the animal's deaths, suggesting that the deposit may represent a school of Shonisaurus that was paralyzed by neurotoxins in the fish or shellfish that they ate before sinking to their death. They compared their hypothesis to modern mass whale deaths off the coast of New England. However, this interpretation is considered doubtful as there is no evidence linking mass whale deaths with consumption of poisonous sealife.[33]
Dino Frey and others reported the presence of ichthyosaur vertebrae in the collection of the Faculty of Geoscience in Linares, Mexico. They expressed interest in returning to Mexico to study the remains further and search for new finds.[42]
Paleontologist Ben Kear collaborated with radiographer George Kourlis to perform a CT scan of Platypterigius. They found that its inner ear bones were so thick that they could not transmit sound vibrations and concluded animal must have been deaf. The scan also exposed the sensory structures inside its nose that allowed it to smell as well as an unusual system of "channels and grooves". The researchers found embryonic remains inside a Platypteriguis from Hughenden, Queensland, as well as the remains of the belemnites, fish, and turtle hatchlings it ate.[74]
Arkhangelsky described the species that would later come to be known as Brachypterygius alekseevi.
2002
Li and You described the new species Cymbospondylus asiaticus. The known remains of this species consisted of two skulls excavated from the Late Triassic Falang Formation of Guizhou Province, China. This was the first known example of the genus in Asia.[75]
Perkins speculated that the channels and grooves uncovered by Kear and Kourlis in the skull of Platypterigius via CT scan formed an electrosensory system similar to those possessed by modern sharks.[74]
Peter Doyle gave an interview to New Scientist magazine discussing acid-etched belemnite shells, that he believed originated as ichthyosaur vomit.[32]
Ryosuke Motani compared the bodies and hydrodynamics of aquatic life with a "thunniform" body plan like dolphins, lamnid sharks, tunas, and the ichthyosaur Stenopterygius quadriscissus. He modeled the motions of a thunniform body and its interaction with the water finding that, contrary to the conclusions of previous research, the tail fin of a thunniform animal was evolved to enable cruising at large body sizes rather than for "propuslive efficiency". He hypothesized that the similar body plans shared between ichthyosaurs and tunas suggest similar high swimming speeds and metabolic rates.[50]
Illustration of an Ophthalmosaurus skull
Stuart Humphries and Graeme Ruxton published a study on the eyes of Ophthalmosaurus.[76] They calculated its eyes to be two and half to four times as light sensitive as the modern elephant seal. Since elephant seals can themselves dive thousands of feet deep, the researchers concluded that increased light sensitivity in deep water was probably not the only evolutionary pressure behind the evolution of large eyes in Ophthalmosaurus. Its large eyes would have given it exceptionally clear vision as well, which would have been useful for tracking small prey and in possible social behavior.[67]
Thegarten Lingham-Soliar argued against Nathalie Bardet's attribution of ichthyosaur extinction to the loss of their preferred food sources in the Cenomanian-Turonian extinction event expanded on his own 1999 attribution of ichthyosaur extinction to biotic factors. During the Cretaceous the evolution of many fish groups trended towards faster swimming body types, making them harder to hunt for adult ichthyosaurs and harder to escape from for newborn ichthyosaurs. This ecological scene favored ambush predators like plesiosaurs and the newly evolved mosasaurs over the ichthyosaurs, who succumbed to the competition.[65]
Elizabeth Nicholls, Chen Wei, and Makato Manabe published an extensive description of a new, complete specimen of Qianichthyosaurus from Guizhou. They observed that it was very similar to the genus Toretocnemus from California and concluded that similar ichthyosaur faunas spanned the Pacific Ocean during the Late Triassic.[24]
A study of phylogenetic relationships of ichthyopterygians is published by Ji et al. (2015); the authors introduced a new name, Grippioidea, for the clade containing the last common ancestor of Utatsusaurus hataii and Grippia longirostris, and all its descendants.[100]
An exceptionally large ichthyosaur radius, possibly belonging to a member of Shastasauridae (which, if confirmed, would indicate that members of the family survived until Early Jurassic) is described from the HettangianBlue Lias Formation (south Wales, United Kingdom) by Martin et al. (2015).[101]
A study of taxonomic richness, disparity and evolutionary rates of ichthyosaurs throughout the Cretaceous period is published by Fischer et al. (2016).[103]
A restudy of "Platypterygius" campylodon is published by Fischer (2016), who transfers this species to the genus Pervushovisaurus.[104]
A revision of the ichthyosaur material of the British Middle and Late Jurassic referable to Ophthalmosaurus icenicus is published by Moon & Kirton (2016).[105]
2017
Delsett and others described the new genus and species Keilhauia nui.
Paparella and others described the new genus and species Gengasaurus.
A study on the emergence date and changes of the evolutionary rate during the ichthyosauromorph evolution is published by Motani et al. (2017).[107]
A jaw fragment of a member of the genus Omphalosaurus is described from the Middle Triassic (Anisian) Karchowice Formation (Poland) by Wintrich, Hagdorn & Sander (2017), representing the first record of Omphalosaurus from shallow marine carbonates and from the Muschelkalk facies.[108]
Description of three nearly complete and well-preserved skulls of Chaohusaurus chaoxianensis, revealing new information on the skull anatomy of the species, is published by Zhou et al. (2017).[109]
A specimen of Ichthyosaurus somersetensis containing an embryo, representing the largest unequivocal specimen of a member of the genus Ichthyosaurus, is described from the Lower Jurassic (lower Hettangian) Blue Lias Formation (United Kingdom) by Lomax & Sachs (2017).[110]
A study aiming to identify sexual dimorphism, taxonomic variation and individual variation among the specimens of Chaohusaurus chaoxianensis is published by Motani et al. (2018).[113]
A survey of the form and distribution of pathological structures in the skeletons of ichthyosaurs is published by Pardo-Pérez et al. (2018).[114]
A study on the microanatomy of vertebral centra of ichthyosaurs, aiming to establish whether there is any variation between the primitive and the most derived forms, is published by Houssaye, Nakajima & Sander (2018).[115]
A large, isolated jaw fragment of a giant ichthyosaur is described from the Upper Triassic (Rhaetian) Westbury Mudstone Formation (United Kingdom) by Lomax et al. (2018), who also reinterpret some putative dinosaur limb bone shafts from the Upper Triassic of Aust Cliff as more likely to be ichthyosaur fossils.[117]
Ichthyosaur fossils, including an incomplete skeleton of a member of the genus Leptonectes, are described from the Lower Jurassic (Pliensbachian) of Asturias (Spain) by Fernández, Piñuela & García-Ramos (2018).[118]
Remains of ichthyosaur embryos, still situated within a fragment of the rib-cage of the parent animal, are described from the Lower Jurassic (Toarcian) Whitby Mudstone Formation (United Kingdom) by Boyd & Lomax (2018).[119]
New specimen of Phalarodon fraasi is described from the Middle Triassic Botneheia Formation (Svalbard, Norway) by Økland et al. (2018).[121]
Redescription of the relocated holotype of Suevoleviathan integer is published by Maxwell (2018), who considers the species Suevoleviathan disinteger to be a junior synonym of S. integer.[122]
A study on specimens of Temnodontosaurus from the Early Jurassic of southern Germany, aiming to document the types of pathologies observed in the skeletons of specimens assigned to this genus, is published by Pardo-Pérez et al. (2018).[123]
Four isolated partial skulls from the Lower Jurassic of the United Kingdom, previously identified as Ichthyosaurus communis, are assigned to the species Protoichthyosaurus prostaxalis and P. applebyi by Lomax & Massare (2018), providing new information on the anatomy of these taxa.[124]
A reassessment of Ichthyosaurus communis and I. intermedius is published by Massare & Lomax (2018), who consider the latter species to be a junior synonym of the former.[125]
A study on the cellular and molecular composition of integumental tissues in an exceptionally preserved specimen of Stenopterygius is published by Lindgren et al. (2018).[126]
New specimen of Palvennia hoybergeti, providing new information on the anatomy of this species, is described from the Upper Jurassic Slottsmøya Member of the Agardhfjellet Formation (Spitsbergen, Norway) by Delsett et al. (2018).[127]
A revision of British ichthyosaur taxa of the Late Jurassic is published by Moon & Kirton (2018).[128]
A study on the phylogenetic relationships of ichthyosaurs will be published by Moon (2019).[130]
A study on the evolution of ichthyosaur body forms and on its impact on the energy demands of ichthyosaur swimming is published by Gutarra et al. (2019).[131]
A study on the flexibility and function of ichthyosaur tails, as indicated by comparisons with shark tails, is published by Crofts, Shehata & Flammang (2019).[132]
A study on the effects of methodology, missing data and exceptional preservation of fossil specimens in lagerstätten on known morphological diversity of fossil animals, as indicated by fossil record of ichthyosaurs, is published by Flannery Sutherland et al. (2019).[133]
Second specimen of Wahlisaurus massarae is reported from a quarry in Somerset (United Kingdom), from the base of the Blue Lias Formation (Triassic–Jurassic boundary) by Lomax, Evans & Carpenter (2019), extending known geographic and stratigraphic range of the species.[134]
A neonate specimen of Ichthyosaurus communis is described by Lomax et al. (2019).[136]
A study on the variation of the hindfin morphology in the specimens of Ichthyosaurus and on its taxonomic utility is published by Massare & Lomax (2019).[137]
A study on the bone microstructure of the skeleton of a specimen of Stenopterygius quadriscissus from the Lower Jurassic Posidonia Shale (Germany) is published by Anderson et al. (2019).[138]
A study on ontogentic variation in the braincase of Stenopterygius is published by Miedema and Maxwell[139]
A study on the anatomy of an ophthalmosaurid rostrum fragment from the Upper Jurassic (Oxfordian) in the Morawica quarry in the Świętokrzyskie Mountains (Poland), and on its implications for reconstructing the internal morphology of the ophthalmosaurid cranial region and inferring the functional adaptations and palaeoecology of these reptiles, will be published by Tyborowski, Skrzycki & Dec (2019).[140]
A revision of the type series of all three species of Undorosaurus is published by Zverkov & Efimov (2019).[141]
A study on the taxonomy and phylogeny of ichthyosaurs belonging to the genus Arthropterygius is published by Zverkov & Prilepskaya (2019).[142]
New fossil remains of Platypterygius sachicarum (a new skull and associated postcranial remains of upper Barremian age) are described from Villa de Leyva, Colombia by Maxwell et al. (2019), representing the first documented postcranial remains of this species.[143]
^Valentin Fischer; Maxim S. Arkhangelsky; Gleb N. Uspensky; Ilya M. Stenshin & Pascal Godefroit (2014). "A new Lower Cretaceous ichthyosaur from Russia reveals skull shape conservatism within Ophthalmosaurinae". Geological Magazine. 151 (1): 60–70. Bibcode:2014GeoM..151...60F. doi:10.1017/S0016756812000994.
^Valentin Fischer; Maxim S. Arkhangelsky; Darren Naish; Ilya M. Stenshin; Gleb N. Uspensky & Pascal Godefroit (2014). "Simbirskiasaurus and Pervushovisaurus reassessed: implications for the taxonomy and cranial osteology of Cretaceous platypterygiine ichthyosaurs". Zoological Journal of the Linnean Society. 171 (4): 822–841. doi:10.1111/zoj.12158.
^Cheng Ji; Da-Yong Jiang; Ryosuke Motani; Olivier Rieppel; Wei-Cheng Hao & Zuo-Yu Sun (2015). "Phylogeny of the Ichthyopterygia incorporating recent discoveries from South China". Journal of Vertebrate Paleontology. 36 (1): e1025956. doi:10.1080/02724634.2015.1025956. S2CID 85621052.
^Jeremy E. Martin; Peggy Vincent; Guillaume Suan; Tom Sharpe; Peter Hodges; Matt Williams; Cindy Howells & Valentin Fischer (2015). "A mysterious giant ichthyosaur from the lowermost Jurassic of Wales". Acta Palaeontologica Polonica. 60 (4): 837–842. doi:10.4202/app.00062.2014.
^Valentin Fischer; Nathalie Bardet; Roger B. J. Benson; Maxim S. Arkhangelsky; Matt Friedman (2016). "Extinction of fish-shaped marine reptiles associated with reduced evolutionary rates and global environmental volatility". Nature Communications. 7: Article number 10825. Bibcode:2016NatCo...710825F. doi:10.1038/ncomms10825. PMC 4786747. PMID 26953824.
^Valentin Fischer (2016). "Taxonomy of Platypterygius campylodon and the diversity of the last ichthyosaurs". PeerJ. 4: e2604. doi:10.7717/peerj.2604. PMC 5075704. PMID 27781178.
^Benjamin C. Moon; Angela M. Kirton (2016). "Ichthyosaurs of the British Middle and Upper Jurassic. Part 1 - Ophthalmosaurus". Monograph of the Palaeontographical Society. 170 (647): 1–84. Bibcode:2016MPalS.170....1M. doi:10.1080/02693445.2016.11963958. hdl:1983/983f82bf-a391-4cbc-b313-1fc754017eef. S2CID 133288616.
^Dean R. Lomax; Judy A. Massare; Rashmiben T. Mistry (2017). "The taxonomic utility of forefin morphology in Lower Jurassic ichthyosaurs: Protoichthyosaurus and Ichthyosaurus". Journal of Vertebrate Paleontology. 37 (5): e1361433. Bibcode:2017JVPal..37E1433L. doi:10.1080/02724634.2017.1361433. S2CID 90238537.
^Ryosuke Motani; Da-yong Jiang; Andrea Tintori; Cheng Ji; Jian-dong Huang (2017). "Pre- versus post-mass extinction divergence of Mesozoic marine reptiles dictated by time-scale dependence of evolutionary rates". Proceedings of the Royal Society B: Biological Sciences. 284 (1854): 20170241. doi:10.1098/rspb.2017.0241. PMC 5443947. PMID 28515201.
^Tanja Wintrich; Hans Hagdorn; P. Martin Sander (2017). "An enigmatic marine reptile—the actual first record of Omphalosaurus in the Muschelkalk of the Germanic basin". Journal of Vertebrate Paleontology. 37 (6): e1384739. Bibcode:2017JVPal..37E4739W. doi:10.1080/02724634.2017.1384739. S2CID 91076880.
^Min Zhou; Da-Yong Jiang; Ryosuke Motani; Andrea Tintori; Cheng Ji; Zuo-Yu Sun; Pei-Gang Ni; Hao Lu (2017). "The cranial osteology revealed by three-dimensionally preserved skulls of the Early Triassic ichthyosauriform Chaohusaurus chaoxianensis (Reptilia: Ichthyosauromorpha) from Anhui, China". Journal of Vertebrate Paleontology. 37 (4): e1343831. Bibcode:2017JVPal..37E3831Z. doi:10.1080/02724634.2017.1343831. S2CID 90332288.
^Dean R. Lomax; Sven Sachs (2017). "On the largest Ichthyosaurus: A new specimen of Ichthyosaurus somersetensis containing an embryo". Acta Palaeontologica Polonica. 62 (3): 575–584. doi:10.4202/app.00376.2017.
^Chloé Plet; Kliti Grice; Anais Pagès; Michael Verrall; Marco J. L. Coolen; Wolfgang Ruebsam; William D. A. Rickard; Lorenz Schwark (2017). "Palaeobiology of red and white blood cell-like structures, collagen and cholesterol in an ichthyosaur bone". Scientific Reports. 7 (1): Article number 13776. Bibcode:2017NatSR...713776P. doi:10.1038/s41598-017-13873-4. PMC 5653768. PMID 29061985.
^Guntupalli V. R. Prasad; Dhirendra K. Pandey; Matthias Alberti; Franz T. Fürsich; Mahesh G. Thakkar; Gaurav D. Chauhan (2017). "Discovery of the first ichthyosaur from the Jurassic of India: Implications for Gondwanan palaeobiogeography". PLOS ONE. 12 (10): e0185851. Bibcode:2017PLoSO..1285851P. doi:10.1371/journal.pone.0185851. PMC 5656312. PMID 29069082.
^Ryosuke Motani; Jiandong Huang; Da-yong Jiang; Andrea Tintori; Olivier Rieppel; Hailu You; Yuan-chao Hu; Rong Zhang (2018). "Separating sexual dimorphism from other morphological variation in a specimen complex of fossil marine reptiles (Reptilia, Ichthyosauriformes, Chaohusaurus)". Scientific Reports. 8 (1): Article number 14978. Bibcode:2018NatSR...814978M. doi:10.1038/s41598-018-33302-4. PMC 6175944. PMID 30297861.
^J. M. Pardo-Pérez; B. P. Kear; M. Gómez; M. Moroni; E. E. Maxwell (2018). "Ichthyosaurian palaeopathology: evidence of injury and disease in fossil 'fish lizards'". Journal of Zoology. 304 (1): 21–33. doi:10.1111/jzo.12517.
^Alexandra Houssaye; Yasuhisa Nakajima; P. Martin Sander (2018). "Structural, functional, and physiological signals in ichthyosaur vertebral centrum microanatomy and histology". Geodiversitas. 40 (7): 161–170. doi:10.5252/geodiversitas2018v40a7.
^Victoria Sjøholt Engelschiøn; Lene Liebe Delsett; Aubrey Jane Roberts; Jørn H. Hurum (2018). "Large-sized ichthyosaurs from the Lower Saurian niveau of the Vikinghøgda Formation (Early Triassic), Marmierfjellet, Spitsbergen". Norwegian Journal of Geology. 98 (2): 239–265. doi:10.17850/njg98-2-05. hdl:10852/71102.
^Dean R. Lomax; Paul De la Salle; Judy A. Massare; Ramues Gallois (2018). "A giant Late Triassic ichthyosaur from the UK and a reinterpretation of the Aust Cliff 'dinosaurian' bones". PLOS ONE. 13 (4): e0194742. Bibcode:2018PLoSO..1394742L. doi:10.1371/journal.pone.0194742. PMC 5890986. PMID 29630618.
^Marta S. Fernández; Laura Piñuela; José Carlos García-Ramos (2018). "First report of Leptonectes (Ichthyosauria: Leptonectidae) from the Lower Jurassic (Pliensbachian) of Asturias, northern Spain". Palaeontologia Electronica. 21 (2): Article number 21.2.29A. doi:10.26879/802. hdl:11336/85063.
^M. J. Boyd; D. R. Lomax (2018). "The youngest occurrence of ichthyosaur embryos in the UK: A new specimen from the Early Jurassic (Toarcian) of Yorkshire". Proceedings of the Yorkshire Geological Society. 62 (2): 77–82. Bibcode:2018PYGS...62...77B. doi:10.1144/pygs2017-008.
^Darío G. Lazo; Marianella Talevi; Cecilia S. Cataldo; Beatriz Aguirre-Urreta; Marta S. Fernández (2018). "Description of ichthyosaur remains from the Lower Cretaceous Agrio Formation (Neuquén Basin, west-central Argentina) and their paleobiological implications". Cretaceous Research. 89: 8–21. Bibcode:2018CrRes..89....8L. doi:10.1016/j.cretres.2018.02.019. hdl:11336/88401. S2CID 133798666.
^Inghild Økland; Lene Liebe Delsett; Aubrey Jane Roberts; Jørn H. Hurum (2018). "A Phalarodon fraasi (Ichthyosauria: Mixosauridae) from the Middle Triassic of Svalbard". Norwegian Journal of Geology. 98 (2): 267–288. doi:10.17850/njg98-2-06. hdl:10852/71100.
^Erin E. Maxwell (2018). "Redescription of the 'lost' holotype of Suevoleviathan integer (Bronn, 1844) (Reptilia: Ichthyosauria)". Journal of Vertebrate Paleontology. 38 (2): e1439833. Bibcode:2018JVPal..38E9833M. doi:10.1080/02724634.2018.1439833. S2CID 91013635.
^Judith M. Pardo-Pérez; Benjamin P. Kear; Heinrich Mallison; Marcelo Gómez; Manuel Moroni; Erin E. Maxwell (2018). "Pathological survey on Temnodontosaurus from the Early Jurassic of southern Germany". PLOS ONE. 13 (10): e0204951. Bibcode:2018PLoSO..1304951P. doi:10.1371/journal.pone.0204951. PMC 6200200. PMID 30356279.
^Dean R. Lomax; Judy A. Massare (2018). "A second specimen of Protoichthyosaurus applebyi (Reptilia: Ichthyosauria) and additional information on the genus and species". Paludicola. 11 (4): 164–178.
^Judy A. Massare; Dean R. Lomax (2018). "A taxonomic reassessment of Ichthyosaurus communis and I. intermedius and a revised diagnosis for the genus". Journal of Systematic Palaeontology. 16 (3): 263–277. Bibcode:2018JSPal..16..263M. doi:10.1080/14772019.2017.1291116.
^Johan Lindgren; Peter Sjövall; Volker Thiel; Wenxia Zheng; Shosuke Ito; Kazumasa Wakamatsu; Rolf Hauff; Benjamin P. Kear; Anders Engdahl; Carl Alwmark; Mats E. Eriksson; Martin Jarenmark; Sven Sachs; Per E. Ahlberg; Federica Marone; Takeo Kuriyama; Ola Gustafsson; Per Malmberg; Aurélien Thomen; Irene Rodríguez-Meizoso; Per Uvdal; Makoto Ojika; Mary H. Schweitzer (2018). "Soft-tissue evidence for homeothermy and crypsis in a Jurassic ichthyosaur". Nature. 564 (7736): 359–365. Bibcode:2018Natur.564..359L. doi:10.1038/s41586-018-0775-x. PMID 30518862. S2CID 54458324.
^Lene Liebe Delsett; Patrick Scott Druckenmiller; Aubrey Jane Roberts; Jørn Harald Hurum (2018). "A new specimen of Palvennia hoybergeti: implications for cranial and pectoral girdle anatomy in ophthalmosaurid ichthyosaurs". PeerJ. 6: e5776. doi:10.7717/peerj.5776. PMC 6187996. PMID 30345178.
^Benjamin C. Moon; Angela M. Kirton (2018). "Ichthyosaurs of the British Middle and Upper Jurassic. Part 2. Brachypterygius, Nannopterygius, Macropterygius and Taxa invalida". Monographs of the Palaeontographical Society. 172 (650): 85–197. Bibcode:2018MPalS.172...85M. doi:10.1080/02693445.2018.1468139. hdl:1983/a003f49d-b8ba-4ff6-abba-f1444147633a. S2CID 133537170.
^Long Cheng; Ryosuke Motani; Da-yong Jiang; Chun-bo Yan; Andrea Tintori; Olivier Rieppel (2019). "Early Triassic marine reptile representing the oldest record of unusually small eyes in reptiles indicating non-visual prey detection". Scientific Reports. 9 (1): Article number 152. Bibcode:2019NatSR...9..152C. doi:10.1038/s41598-018-37754-6. PMC 6345829. PMID 30679783.
^Benjamin C. Moon (2019). "A new phylogeny of ichthyosaurs (Reptilia: Diapsida)". Journal of Systematic Palaeontology. 17 (2): 129–155. Bibcode:2019JSPal..17..129M. doi:10.1080/14772019.2017.1394922. hdl:1983/463e9f78-10b7-4262-9643-0454b4aa7763. S2CID 90912678.
^Susana Gutarra; Benjamin C. Moon; Imran A. Rahman; Colin Palmer; Stephan Lautenschlager; Alison J. Brimacombe; Michael J. Benton (2019). "Effects of body plan evolution on the hydrodynamic drag and energy requirements of swimming in ichthyosaurs". Proceedings of the Royal Society B: Biological Sciences. 286 (1898): Article ID 20182786. doi:10.1098/rspb.2018.2786. PMC 6458325. PMID 30836867.
^S. B. Crofts; R. Shehata; B. Flammang (2019). "Flexibility of heterocercal tails: what can the functional morphology of shark tails tell us about ichthyosaur swimming?". Integrative Organismal Biology. 1 (1): obz002. doi:10.1093/iob/obz002. PMC 7671117. PMID 33791519.
^Joseph T. Flannery Sutherland; Benjamin C. Moon; Thomas L. Stubbs; Michael J. Benton (2019). "Does exceptional preservation distort our view of disparity in the fossil record?". Proceedings of the Royal Society B: Biological Sciences. 286 (1897): Article ID 20190091. doi:10.1098/rspb.2019.0091. PMC 6408902. PMID 30963850.
^Dean R. Lomax; Mark Evans; Simon Carpenter (2019). "An ichthyosaur from the UK Triassic–Jurassic boundary: A second specimen of the leptonectid ichthyosaur Wahlisaurus massarae Lomax 2016". Geological Journal. 54 (1): 83–90. Bibcode:2019GeolJ..54...83L. doi:10.1002/gj.3155.
^Dean R. Lomax; Laura B. Porro; Nigel R. Larkin (2019). "Descriptive anatomy of the largest known specimen of Protoichthyosaurus prostaxalis (Reptilia: Ichthyosauria) including computed tomography and digital reconstruction of a three-dimensional skull". PeerJ. 7: e6112. doi:10.7717/peerj.6112. PMC 6329338. PMID 30643690.
^Dean R. Lomax; Nigel R. Larkin; Ian Boomer; Steven Dey; Philip Copestake (2019). "The first known neonate Ichthyosaurus communis skeleton: a rediscovered specimen from the Lower Jurassic, UK" (PDF). Historical Biology: An International Journal of Paleobiology. 31 (5): 600–609. Bibcode:2019HBio...31..600L. doi:10.1080/08912963.2017.1382488. S2CID 89922569.
^Judy A. Massare; Dean R. Lomax (2019). "Hindfins of Ichthyosaurus: effects of large sample size on 'distinct' morphological characters". Geological Magazine. 156 (4): 725–744. Bibcode:2019GeoM..156..725M. doi:10.1017/S0016756818000146. S2CID 134945422.
^Katherine L. Anderson; Patrick S. Druckenmiller; Gregory M. Erickson; Erin E. Maxwell (2019). "Skeletal microstructure of Stenopterygius quadriscissus (Reptilia, Ichthyosauria) from the Posidonienschiefer (Posidonia Shale, Lower Jurassic) of Germany". Palaeontology. 62 (3): 433–449. Bibcode:2019Palgy..62..433A. doi:10.1111/pala.12408.
^Miedema, Feiko; Maxwell, Erin E. (2019-07-04). "Ontogeny of the braincase in Stenopterygius (Reptilia, Ichthyosauria) from the Lower Jurassic of Germany". Journal of Vertebrate Paleontology. 39 (4): e1675164. Bibcode:2019JVPal..39E5164M. doi:10.1080/02724634.2019.1675164. ISSN 0272-4634.
^Daniel Tyborowski; Piotr Skrzycki; Marek Dec (2019). "Internal structure of ichthyosaur rostrum from the Upper Jurassic of Poland with comments on ecomorphological adaptations of ophthalmosaurid skull". Historical Biology: An International Journal of Paleobiology. 32 (7): 1–10. doi:10.1080/08912963.2018.1559308. S2CID 92555385.
^Nikolay G. Zverkov; Vladimir M. Efimov (2019). "Revision of Undorosaurus, a mysterious Late Jurassic ichthyosaur of the Boreal Realm". Journal of Systematic Palaeontology. 17 (14): 963–993. Bibcode:2019JSPal..17.1183Z. doi:10.1080/14772019.2018.1515793. S2CID 91912834.
^Nikolay G. Zverkov; Natalya E. Prilepskaya (2019). "A prevalence of Arthropterygius (Ichthyosauria: Ophthalmosauridae) in the Late Jurassic—earliest Cretaceous of the Boreal Realm". PeerJ. 7: e6799. doi:10.7717/peerj.6799. PMC 6497043. PMID 31106052.
^Erin E. Maxwell; Dirley Cortés; Pedro Patarroyo; Mary Luz Parra Ruge (2019). "A new specimen of Platypterygius sachicarum (Reptilia, Ichthyosauria) from the Early Cretaceous of Colombia and its phylogenetic implications". Journal of Vertebrate Paleontology. 39 (1): e1577875. Bibcode:2019JVPal..39E7875M. doi:10.1080/02724634.2019.1577875. S2CID 146059015.
^Lisandro Campos; Marta S. Fernández; Yanina Herrera (2020). "A new ichthyosaur from the Late Jurassic of north-west Patagonia (Argentina) and its significance for the evolution of the narial complex of the ophthalmosaurids". Zoological Journal of the Linnean Society. 188 (1): 180–201. doi:10.1093/zoolinnean/zlz095.
^Jian-dong Huang; Ryosuke Motani; Da-yong Jiang; Andrea Tintori; Olivier Rieppel; Min Zhou; Xin-Xin Ren; Rong Zhang (2019). "The new ichthyosauriform Chaohusaurus brevifemoralis (Reptilia, Ichthyosauromorpha) from Majiashan, Chaohu, Anhui Province, China". PeerJ. 7: e7561. doi:10.7717/peerj.7561. PMC 6741286. PMID 31565558.
^Jair Israel Barrientos Lara; Jesús Alvarado Ortega; Marta S.Fernández (2020). "Acuetzpalin carranzai gen et sp. nov. A new ophthalmosauridae (Ichthyosauria) from the Upper Jurassic of Durango, North Mexico". Journal of South American Earth Sciences. 98: Article 102456. Bibcode:2020JSAES..9802456B. doi:10.1016/j.jsames.2019.102456. S2CID 213102661.
References
M.S. Arkhangelsky; N.G. Zverkov (2014). "On a new ichthyosaur of the genus Undorosaurus" (PDF). Proceedings of the Zoological Institute of the Russian Academy of Sciences. 318 (3): 187–196.
Stephen L. Brusatte, Mark T. Young, Thomas J. Challands, Neil D. L. Clark, Valentin Fischer, Nicholas C. Fraser, Jeff J. Liston, Colin C. J. MacFadyen, Dugald A. Ross, Stig Walsh and Mark Wilkinson (2015). "Ichthyosaurs from the Jurassic of Skye, Scotland". Scottish Journal of Geology. 51 (1): 43–55. Bibcode:2015ScJG...51...43B. doi:10.1144/sjg2014-018. hdl:2268/176434. S2CID 54614526.{{cite journal}}: CS1 maint: multiple names: authors list (link)
Chen Xiao-hong & Cheng Long (2010). "A new species of Mixosaurus (Reptilia: Ichthyosauria) from the Middle Triassic of Pu'an, Guizhou, China". Acta Palaeontologica Sinica (2): 251–260.
Xiaohong Chen, P. Martin Sander, Long Cheng and Xiaofeng Wang (2013). "A New Triassic Primitive Ichthyosaur from Yuanan, South China". Acta Geologica Sinica (English Edition). 87 (3): 672–677. Bibcode:2013AcGlS..87..672C. doi:10.1111/1755-6724.12078. S2CID 140143030.{{cite journal}}: CS1 maint: multiple names: authors list (link)
Xiao-hong Chen; Ryosuke Motani; Long Cheng; Da-yong Jiang; Olivier Rieppel (2015). "A New Specimen of Carroll's Mystery Hupehsuchian from the Lower Triassic of China". PLOS ONE. 10 (5): e0126024. Bibcode:2015PLoSO..1026024C. doi:10.1371/journal.pone.0126024. PMC 4446317. PMID 26017585.
Robin S. Cuthbertson; Anthony P. Russell; Jason S. Anderson (2013). "Cranial morphology and relationships of a new grippidian (Ichthyopterygia) from the Vega-Phroso Siltstone Member (Lower Triassic) of British Columbia, Canada". Journal of Vertebrate Paleontology. 33 (4): 831–847. Bibcode:2013JVPal..33..831C. doi:10.1080/02724634.2013.755989. S2CID 131501541.
Patrick S. Druckenmiller & Erin E. Maxwell (2010). "A new Lower Cretaceous (lower Albian) ichthyosaur genus from the Clearwater Formation, Alberta, Canada". Canadian Journal of Earth Sciences. 47 (8): 1037–1053. Bibcode:2010CaJES..47.1037D. doi:10.1139/E10-028. Retrieved 14 January 2011.[permanent dead link]
Patrick S. Druckenmiller, Jørn H. Hurum, Espen M. Knutsen and Hans Arne Nakrem (2012). "Two new ophthalmosaurids (Reptilia: Ichthyosauria) from the Agardhfjellet Formation (Upper Jurassic: Volgian/Tithonian), Svalbard, Norway" (PDF). Norwegian Journal of Geology. 92 (2–3): 311–339.{{cite journal}}: CS1 maint: multiple names: authors list (link)[permanent dead link]
Ellis, Richard (2003). Sea Dragons - Predators of the Prehistoric Oceans. University Press of Kansas. ISBN 978-0-7006-1269-7.
Emling, Shelley (2009). The Fossil Hunter: Dinosaurs, Evolution, and the Woman whose Discoveries Changed the World. Palgrave Macmillan. ISBN 978-0-230-61156-6.
Fischer, V.; Masure, E.; Arkhangelsky, M.S.; and Godefroit, P. (2011). "A new Barremian (Early Cretaceous) ichthyosaur from western Russia". Journal of Vertebrate Paleontology. 31 (5): 1010–1025. Bibcode:2011JVPal..31.1010F. doi:10.1080/02724634.2011.595464. hdl:2268/92828. S2CID 86036325.{{cite journal}}: CS1 maint: multiple names: authors list (link)
Fischer,V.; Maisch, M.W.; Naish, D.; Kosma, R.; Liston, J.; Joger, U.; Krüger, F.J.; Pérez,J.P.; Tainsh, J.; Appleby, R.M. (2012). "New Ophthalmosaurid Ichthyosaurs from the European Lower Cretaceous Demonstrate Extensive Ichthyosaur Survival across the Jurassic–Cretaceous Boundary". PLOS ONE. 7 (1): e29234. Bibcode:2012PLoSO...729234F. doi:10.1371/journal.pone.0029234. PMC 3250416. PMID 22235274.
Valentin Fischer, Robert M. Appleby, Darren Naish, Jeff Liston, James B. Riding, Stephen Brindley and Pascal Godefroit (2013). "A basal thunnosaurian from Iraq reveals disparate phylogenetic origins for Cretaceous ichthyosaurs". Biology Letters. 9 (4): 20130021. doi:10.1098/rsbl.2013.0021. PMC 3730615. PMID 23676653.{{cite journal}}: CS1 maint: multiple names: authors list (link)
Valentin Fischer; Maxim S. Arkhangelsky; Gleb N. Uspensky; Ilya M. Stenshin; Pascal Godefroit (2014). "A new Lower Cretaceous ichthyosaur from Russia reveals skull shape conservatism within Ophthalmosaurinae". Geological Magazine. 151 (1): 60–70. Bibcode:2014GeoM..151...60F. doi:10.1017/S0016756812000994.
Valentin Fischer; Nathalie Bardet; Myette Guiomar; Pascal Godefroit (2014). "High Diversity in Cretaceous Ichthyosaurs from Europe Prior to Their Extinction". PLOS ONE. 9 (1): e84709. Bibcode:2014PLoSO...984709F. doi:10.1371/journal.pone.0084709. PMC 3897400. PMID 24465427.
Nadia B. Fröbisch; Jörg Fröbisch; P. Martin Sander; Lars Schmitz; Olivier Rieppel (2013). "Macropredatory ichthyosaur from the Middle Triassic and the origin of modern trophic networks". Proceedings of the National Academy of Sciences of the United States of America. 110 (4): 1393–1397. Bibcode:2013PNAS..110.1393F. doi:10.1073/pnas.1216750110. PMC 3557033. PMID 23297200.
Da-Yong Jiang; Ryosuke Motani; Jian-Dong Huang; Andrea Tintori; Yuan-Chao Hu; Olivier Rieppel; Nicholas C. Fraser; Cheng Ji; Neil P. Kelley; Wan-Lu Fu; Rong Zhang (2016). "A large aberrant stem ichthyosauriform indicating early rise and demise of ichthyosauromorphs in the wake of the end-Permian extinction". Scientific Reports. 6: Article number 26232. Bibcode:2016NatSR...626232J. doi:10.1038/srep26232. PMC 4876504. PMID 27211319.
Dean R. Lomax & Judy A. Massare (2015). "A new species of Ichthyosaurus from the Lower Jurassic of West Dorset, England, U.K." Journal of Vertebrate Paleontology. 35 (2): e903260. Bibcode:2015JVPal..35E3260L. doi:10.1080/02724634.2014.903260. S2CID 85745787.
Michael W. Maisch (2010). "Phylogeny, systematics, and origin of the Ichthyosauria – the state of the art" (PDF). Palaeodiversity. 3: 151–214. Retrieved 14 January 2011.
Jeremy E. Martin, Valentin Fischer, Peggy Vincent and Guillaume Suan (2012). "A longirostrine Temnodontosaurus (Ichthyosauria) with comments on Early Jurassic ichthyosaur niche partitioning and disparity". Palaeontology. 55 (5): 995–1005. Bibcode:2012Palgy..55..995M. doi:10.1111/j.1475-4983.2012.01159.x.{{cite journal}}: CS1 maint: multiple names: authors list (link)
Maisch, M. W.; Matzke, A. T. (2000). "The Ichthyosauria". Stuttgarter Beiträge zur Naturkunde, Serie B (Geologie und Paläontologie). 298: 1–159.
Maxwell, E. E (2010). "Generic reassignment of an ichthyosaur from the Queen Elizabeth Islands, Northwest Territories, Canada". Journal of Vertebrate Paleontology. 30 (2): 403–415. Bibcode:2010JVPal..30..403M. doi:10.1080/02724631003617944. S2CID 85143039.
Erin E. Maxwell; Marta S. Fernández; Rainer R. Schoch (2012). "First Diagnostic Marine Reptile Remains from the Aalenian (Middle Jurassic): A New Ichthyosaur from Southwestern Germany". PLOS ONE. 7 (8): e41692. Bibcode:2012PLoSO...741692M. doi:10.1371/journal.pone.0041692. PMC 3411580. PMID 22870244.
Erin E. Maxwell, Daniel Dick, Santiago Padilla and Mary Luz Parra (2015). "A new ophthalmosaurid ichthyosaur from the Early Cretaceous of Colombia". Papers in Palaeontology. 2: 59–70. doi:10.1002/spp2.1030. S2CID 128464793.{{cite journal}}: CS1 maint: multiple names: authors list (link)
Mayor, Adrienne (2005). Fossil Legends of the First Americans. Princeton University Press. ISBN 978-0-691-11345-6.
McGowan (1994). "The taxonomic status of the Upper Liassic ichthyosaur Eurhinosaurus longirostris". Palaeontology. 37 (4): 747–753.
Ryosuke Motani; Da-Yong Jiang; Guan-Bao Chen; Andrea Tintori; Olivier Rieppel; Cheng Ji; Jian-Dong Huang (2015). "A basal ichthyosauriform with a short snout from the Lower Triassic of China". Nature. 517 (7535): 485–488. Bibcode:2015Natur.517..485M. doi:10.1038/nature13866. PMID 25383536. S2CID 4392798.
Nicholls, E. L.; Manabe, M. (2001). "A new genus of ichthyosaur from the Late Triassic Pardonet Formation of British Columbia: bridging the Triassic-Jurassic gap". Canadian Journal of Earth Sciences. 38 (6): 983–1002. Bibcode:2001CaJES..38..983N. doi:10.1139/cjes-38-6-983.
Aubrey Jane Roberts; Patrick Scott Druckenmiller; Glenn-Peter Sætre; Jørn Harald Hurum (2014). "A New Upper Jurassic Ophthalmosaurid Ichthyosaur from the Slottsmøya Member, Agardhfjellet Formation of Central Spitsbergen". PLOS ONE. 9 (8): e103152. Bibcode:2014PLoSO...9j3152R. doi:10.1371/journal.pone.0103152. PMC 4118863. PMID 25084533.
External links
Media related to Ichthyosauromorpha at Wikimedia Commons
Works related to Category:Ichthyosaurs at Wikisource