Temnodontosaurus

Not to be confused with Tenontosaurus.

Temnodontosaurus Temporal range: Hettangian-Toarcian 201.3–175.6  Ma PreꞒ Ꞓ O S D C P T J K Pg N
Mounted skeleton of T. trigonodon in metal frame at the State Museum of Natural History Stuttgart, Germany
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	† Ichthyosauria
Family:	† Temnodontosauridae McGowan, 1974
Genus:	† Temnodontosaurus Lydekker, 1889
Type species
†Temnodontosaurus platyodon (Conybeare, 1822)
Other species
List Recognized species † T. trigonodon(von Theodori, 1843) † T. crassimanus(Blake, 1876) † T. zetlandicus(Seeley, 1876) † T. nuertingensis(von Huene, 1931) Disputed species † T.? eurycephalus McGowan, 1974 † T.? azerguensisMartin et al., 2012
Synonyms
List of synonyms Synonyms of genus [1] : 71  [2] : 85  Proteosaurus? Home, 1814 Oligostinus Hawkins, 1840 Synonyms of T. platyodon [3] [4] [5] [2] : 85  Ichthyosaurus platyodonConybeare, 1822 Ichthyosaurus chiroligostinusHawkins, 1834 Ichthyosaurus lonchiodon Owen, 1840 Leptopterygius lonchiodonvon Huene, 1922 Leptopterygius platyodonvon Huene, 1922 Proteosaurus platyodon Hay, 1902 Temnodontosaurus risorMcGowan, 1974 Synonyms of T. trigonodon [2] : 85–87  Ichthyosaurus trigonodonvon Theodori, 1843 Ichthyosaurus ingensvon Theodori, 1854 Ichthyosaurus multiscissus Quenstedt, 1885 Ichthyosaurus burgundiae Gaudry, 1892 Leptopterygius trigonodonvon Huene, 1931 Leptopterygius burgundiaeMcGowan, 1979 Temnodontosaurus burgundiaeMcGowan, 1996 Synonymes of T. crassimanus [2] : 87  [6] Ichthyosaurus crassimanusBlake, 1876 Synonyms of T. zetlandicus [7] Ichthyosaurus zetlandicusSeeley, 1880 Ichthyosaurus longifronsOwen, 1881 Stenopterygius zetlandicusvon Huene, 1922 Synonyms of T. nuertingensis [8] Ichthyosaurus bellicosus Fraas, 1926 Leptopterygius nürtingensisvon Huene, 1931

Temnodontosaurus (meaning "cutting-tooth lizard") is an extinct genus of large ichthyosaurs that lived during the Lower Jurassic in what is now Europe and possibly Chile. The first known fossil is a specimen consisting of a complete skull and partial skeleton discovered on a cliff by Joseph and Mary Anning around the early 1810s in the Dorset county, England. The anatomy of this specimen was subsequently analyzed in a series of articles written by Everard Home between 1814 and 1819, making it the very first ichthyosaur to have been scientifically described. In 1822, the specimen was assigned to the genus Ichthyosaurus by William Conybeare, and more precisely to the species I. platyodon. Noting the large dental differences with other species of Ichthyosaurus, Richard Lydekker suggested in 1889 moving this species into a separate genus, which he named Temnodontosaurus. While many species have been assigned to the genus, only five are currently recognized as valid, the others being considered as synonymous, doubtful or possibly belonging to other taxa.

Generally estimated at 9 m (30 ft) long, Temnodontosaurus is one of the largest known ichthyosaurs, although not as imposing as some Triassic forms. Specimens assigned to the genus may nevertheless have reached larger measurements. As an ichthyosaur, Temnodontosaurus had flippers for limbs and a fin on the tail. Boasting eye sockets measuring more than 25 cm (9.8 in) wide, Temnodontosaurus quite possibly had the largest eyes known in the entire animal kingdom, rivaling in size those of the colossal squid. The snout appears to be longer than the mandible, being equipped with several sharp teeth (hence its name). On the basis of numerous very complete skeletons, it is estimated that the animal had at least more than 40 presacral vertebrae. Temnodontosaurus is a basal representative of the parvipelvian subgroup of ichthyosaurs, in addition to being its largest representative. A monotypic family, Temnodontosauridae, was even established in 1974 to include the genus. Various phylogenetic analyses as well as diagnostic problems concerning the genus make it, for the moment, a polyphyletic taxon (unnatural grouping), and therefore in need of revision.

Research history

Discovery and identification

Illustrations by Everard Home of the first known specimen of T. platyodon (NHMUK PV R1158), discovered by Joseph and Mary Anning at Black Ven

Temnodontosaurus is historically the very first ichthyosaur to have been scientifically described. ^{[9] [2] : 1} Around 1810, ^[a] a certain Joseph Anning discovered the first skull of the taxon on the cliffs of Black Ven, between the town of Lyme Regis and the village of Charmouth, two localities located in the county of Dorset, in the south of England. The remaining skeleton was later discovered by his sister, the now famous Mary Anning, in 1812. Although other ichthyosaur skeletons had been discovered locally and elsewhere, this particular specimen was the first to attract attention of the scientific community. After the discovery was announced in the press, the specimen was purchased by the lord of a local manor, Henry Hoste Henley, for a price of £23. Subsequently, Henley passed the fossils on to the naturalist William Bullock, who put them on display in the collections of his museum in London. In 1819, Bullock's own collection was sold to the Natural History Museum in London for a price of around £47. The specimen, now cataloged as NHMUK PV R1158, is still currently housed at this museum, although the postcranial remains have since been lost. ^{[4] [10] [11] [2] : 1}

Beginning in 1814, Everard Home wrote a series of six papers for the Royal Society describing the specimen, initially identifying it as a crocodile. ^[12] Perplexed as to the real nature of the fossil, Home kept changing his mind about its classification, thinking that it would be a fish, then as an animal sharing affinities with the platypus, which was then recently described at that time. Finally, in 1819, he thought that the fossil represented an animal that embodied an intermediate form between salamanders and lizards, which led him to erect the genus name Proteosaurus (originally written as Proteo-Saurus). ^[13] In 1821, Henry De la Beche and his colleague William Daniel Conybeare made the very first scientific description of Ichthyosaurus , but did not name any species. ^[14] Although being initially a nomen nudum , this generic name was already proposed in 1818 by Charles Konig, but was thus chosen as the definitive scientific name of this genus, Proteosaurus having since become a nomen oblitum . ^{[2] : 1} In their article, De la Beche and Conybeare refer several additional fossils discovered at Black Ven to this genus, also including the specimen originally described by Home, and finally identify it as a marine reptile. ^[14] It was in 1822 that De la Beche named three species of Ichthyosaurus on the basis of several anatomical differences distinguishing the specimens, one of them being I. platyodon. He nevertheless announces that future descriptions will be done with the help of Conybeare. ^[15] However, it was Conybeare himself who described the fossils the same year, attributing the largest specimens to I. platyodon, ^[16] The specific name platyodon comes from the Ancient Greek πλατύς (platús, "flat", "broad"), and ὀδούς (odoús, "tooth"), ^{[17] : 476} all meaning "flat teeth", in reference to the rather distinctive dentition of this species. ^{[18] : 116}

Various fossil specimens of T. platyodon on display at the Natural History Museum in London, England. In the center, the neotype skeleton (NHMUK PV R2003), with the first specimen discovered (NHMUK PV R1158) being present at the bottom left. The vertebrae at the bottom right come from another individual

In 1889, Henry Alleyne Nicholson and Richard Lydekker published a two-volume work that served as an introduction to the rules of paleontology for students. However, it is in the second volume that the two paleontologists gave a very detailed description of numerous prehistoric vertebrates, and during which the taxonomy of I. platyodon took another direction. Indeed, in his correction notes, Lydekker noticed that the teeth of I. platyodon had great differences from those of other previously recognized species of Ichthyosaurus and suggest that the latter could be the type species of a completely new genus of ichthyosaurs, which he named Temnodontosaurus. ^{[19] : xi  [b]} This generic name is formed from the Ancient Greek τέμνω (temnō, "to cut"), ὀδούς (odoús, "tooth"), and σαῦρος (saûros, "lizard"), ^{[17] : 476, 630, 709} to give "cutting-tooth lizard". ^{[20] [21]} In a broad review of fossil vertebrates published in 1902, Oliver Perry Hay suggested that because the name Proteosaurus technically took precedence over Ichthyosaurus, he then displaced I. platyodon as the type species of that genus, then renamed Proteosaurus platyodon. ^[3] In 1972, Christopher McGowan again used this combination proposed by Hay (although not mentioned), ^{[22] [23]} but the latter revised his judgment two years later, in 1974, in which he moved this species to Temnodontosaurus, as originally proposed by Lydekker. ^[4] The holotype of Temnodontosaurus platyodon consisted of a single tooth which was preserved by the Geological Society of London. ^[24] As the latter has since been noted as lost in 1960, McGowan designated specimen NHMUK PV R2003 as the neotype of this taxon. ^{[4] [2] : 85} This specimen, already mentioned as a representative of the species by Richard Owen in 1881, ^{[18] : 115–116} was originally discovered and partly collected by Mary Anning in July 1832 in Lyme Regis. ^[25] After the discovery, she sold the find to Thomas Hawkins, who himself sold the specimen to the Natural History Museum in London in 1834 for a price of £210. ^[26]

Other species

Recognized species

PB 1, the holotype specimen of T. trigonodon, at the Banz Abbey Museum, Bad Staffelstein, in Bavaria, Germany

In 1843, Carl von Theodori  [ de ] described a new species of Ichthyosaurus, I. trigonodon, which he described as "colossal", based on an imposing specimen comprising a complete skull and a partial postcranial skeleton discovered in the town of Holzmaden in the state of Baden-Württemberg, Germany. ^[27] The specific name comes from Ancient Greek τρίγωνον (trígônon, "triangle") and ὀδούς (odoús, "tooth"), ^{[17] : 476, 714} in reference to the dental crown which is visibly triangular in this species. ^{[2] : 87} In 1854, von Theodori made a much more in-depth description of the holotype specimen. ^[28] In 1889, only some time before he established the genus Temnodontosaurus, Lydekker noted that the dentition of I. trigonodon was quite similar to that of I. platyodon. ^[29] Based on these dental characteristics, he moved this species to the genus Temnodontosaurus the following year, consequently being renamed T. trigonodon. ^[30] In 1931, Friedrich von Huene transferred this species to the genus Leptopterygius. ^{[31] [c]} In 1998, Michael W. Maisch moved the species again to the genus Temnodontosaurus, and attributed to this taxon other, mostly very complete, specimens having been discovered in Germany and France. ^[33] This classification has since been retained in subsequent works, ^{[2] : 87} to the point that a large specimen discovered in England in 2021, nicknamed as the ‘Rutland Sea Dragon’, was even considered as the first probable representative within this country. ^[25] However, a 2023 morphological study conducted by Rebecca F. Bennion and colleagues shows that the holotype specimen differs in cranial and dental traits from other specimens since assigned to the species. The authors therefore suggest that a future re-evaluation is necessary for better a diagnosis of T. trigonodon. ^[34]

In 1857, an almost complete skeleton of a large ichthyosaur was discovered north of the English town of Whitby, located in the Yorkshire county. The latter was also found near another skeleton, that of a pliosaur, which is today recognized as the holotype specimen of Rhomaleosaurus cramptoni . Shortly after its discovery, the ichthyosaurian skeleton was subsequently sent to the Yorkshire Museum, where it was cataloged as YORYM 497. ^{[35] : 45  [6]} The following year, 1858, Owen examined the specimen and classified it as distinct from I. platyodon, attributing it to a completely new species which he named I. crassimanus. However, the latter was never scientifically described by Owen, ^{[36] [35] : 45} although it is briefly mentioned in a work by John Phillips and Robert Etheridge published in 1875. ^[37] It was in 1876 that John Frederick Blake made the first scientific description of the animal, although he did so only very briefly. ^[38] In 1889, Lydekker considered this species as a potential junior synonym of I. trigonodon, ^[29] an opinion which was followed by numerous authors until around the beginning of the 20th century. ^{[35] : 45} In 1930, Sidney Melmore made the first in-depth description of I. crassimanus based on the holotype specimen, restoring the distinct status of the species. ^[36] In his revision published in 1974, McGowan synonymized I. crassimanus with the proposed taxon Stenopterygius acutirostis, also attributing other specimens discovered in the original locality. ^[4] In 2003, McGowan and Ryosuke Motani suggested that all specimens historically attributed to I. crassimanus appeared sufficiently different from T. platyodon and T. trigonodon to belong to a distinct species of the genus Temnodontosaurus, being renamed T. crassimanus. However, they note that further research could question its validity. ^{[2] : 87–88} Long remaining an under-analyzed taxon, it was in 2020 that Emily J. Swaby wrote a thesis considerably revising it. Contrary to the suggestion previously made by McGowan and Motani, Swaby maintains the attribution of this species to Temnodontosaurus. ^[35] The descriptions of this same thesis were finally published the following year in a study co-authored with Daniel R. Lomax. ^[6]

CAMSM J35176, the holotype skull of T. zetlandicus

In 1880, Harry Govier Seeley described the species I. zetlandicus on the basis of a well-preserved skull loaned by an Earl of Shetland (hence its name) around an unspecified date to the Sedgwick Museum of Earth Sciences in Cambridge, in the Cambridgeshire county. This skull, cataloged as CAMSM J35176, was discovered in the coasts of Whitby, near the locality where T. crassimanus was already discovered. ^[39] In 1922, von Huene moved the species within Stenopterygius. ^[40] In 1974, McGowan considered S. zetlandicus as a synonym of S. acutirostris, ^[4] before this species was itself synonymized with T. acutirostris from 1997. ^{[8] [41] : 165} In 2022, Antoine Laboury and colleagues reestablished the validity of the species by redescribing CAMSM J35176, but moved it to the genus Temnodontosaurus, being renamed T. zetlandicus. In their description, they attribute another specimen to the taxon, cataloged as MNHNL TU885, a partial skull which was originally discovered in Schouweiler, southern Luxembourg. ^[7]

In 1931, von Huene described a new species of the genus Leptopterygius, L. nürtingensis, based on a skull and some postcranial remains of a single specimen discovered in a quarry in the town of Nürtingen (hence its name), Baden-Württemberg, Germany. ^{[42] [1] : 72} This specimen, cataloged as SMNS 13488, is mentioned for the first time in a work by Eberhard Fraas published posthumously in 1919, in which the author considers it to be the representative of an undetermined species of Ichthyosaurus. In another work also published posthumously in 1926, Fraas attributed this specimen to a proposed new species which he named I. bellicosus. Fraas was initially expected to carry out the first scientific description of this taxon, but the latter's premature death in 1915 prevented this project from being achieved. Thus, in the absence of a scientific description, the name I. bellicosus is seen as a nomen nudum, and therefore does not have priority over L. nürtingensis. ^[8] Although L. nürtingensis was only officially described in 1931 by von Huene, ^[42] the taxon was already mentioned a year earlier by the same author in an article concerning the ribs of the holotype specimen, ^[43] which have since been noted as lost. ^[44] In 1939, Oskar Kuhn assimilated an incomplete specimen discovered in Aue-Fallstein, Lower Saxony, to this species. ^[45] However, Kuhn did not present sufficient evidence to confirm his claims, and the specimen has since been viewed as indeterminate. ^[8] In 1979, McGowan carried out a large revision of the ichthyosaurs known from Germany, in which he classified L. nürtingensis as a nomen dubium . ^[46] In 1997, Maisch and Axel Hungerbühler formally criticized McGowan's view, given that the holotype specimen is preserved in an excellent state of conservation and is easily diagnosable. He then redescribed this specimen and considered it to be attributable to Temnodontosaurus. In their analysis, the authors change the typography of the species nürtingensis to nuertingensis, due to rule 32.C of the ICZN requiring it. ^[8] The species is again considered a nomen dubium by McGowan and Motani in 2003, ^{[2] : 90} but its validity as well as its belonging to this genus is maintained in subsequent studies. ^{[44] [7] [34]}

Dubious species

Holotype skull and life restoration of T. eurycephalus.

In 1881, Owen attributed a large isolated skull discovered at Lyme Regis, cataloged as NHMUK PV R1157, ^{[4] [2] : 88} to the newly erected species of the genus Ichthyosaurus, I. breviceps. ^{[18] : 110} In 1922, von Huene moved this species to the genus Eurypterygius, ^{[40] : 8} a taxon which is itself recognized as a junior synonym of Ichthyosaurus. ^{[2] : 91} Although I. breviceps is still recognized as belonging to this genus, the large skull historically attributed to the species has large differences with the holotype specimen. ^{[2] : 88, 95} Noting this, McGowan redescribed this specimen in more detail and made it the holotype of an entirely new species of Temnodontosaurus, T. eurycephalus. The specific name comes from the Ancient Greek ευρύς (eurús, "broad"), and κεφαλή (kephalế, "head"), all meaning "broad head", in reference to the cranial morphology of the taxon. ^[4]

In 1984, an almost complete skeleton of a large ichthyosaur was discovered in the Lafarge quarries in the French commune of Belmont-d'Azergues, located near Lyon. Although the specimen is mentioned in a detailed biostratigraphic analysis of the Lafarge quarries published in 1991, ^[47] it was in 2012 when the fossil, uncatalogued but stored in the Saint-Pierre-la-Palud local mining museum  [ fr ], was officially designated as the holotype of the new species T. azerguensis by Jeremy E. Martin and his colleagues. The specific name comes from the Azergues, a river located near the site of the discovery. ^[48]

In 2014, American paleontologist Darren Naish expressed doubts in a blog in the journal Scientific American about the attribution of these two species to Temnodontosaurus, noting their large anatomical differences highlighting the need for a taxonomic revision of this genus. ^[49] A similar observation is shared in the study describing T. zetlandicus in 2022, with the authors mentioning these two species as too phylogenetically unstable to be included in a monophyletic grouping of Temnodontosaurus. ^[7]

Formerly assigned species

In 1840, Owen named the species I. acutirostris on the basis of a partial skeleton discovered near Whitby, now numbered NHMUK PV OR 14553. The holotype specimen was for a long time noted as lost, but this was only in 2002 when it was officially found, although some anatomical parts such as the snout are missing. ^{[41] : 165  [7]} Even before the specimen was found, some studies classified this species within the genus Temnodontosaurus, as Maisch and Hungerbühler did in 1997. ^[8] However, Maisch reversed his decision in 2010, citing that numerous cranial features prove it is not part of the genus. Therefore, the author withdraws his attribution of this specimen to Temnodontosaurus and instead suggests that the latter would be the representative of a completely new genus. ^{[41] : 165} In 2022, Laboury and colleagues share the same conclusions and considers "I." acutirostris as a species inquirenda . ^[7]

Skulls historically attributed to T. burgundiae (the holotype specimen being at the top), exhibited at the National Museum of Natural History in Paris, France.

In 1892, Albert Gaudry officially described a new species of Ichthyosaurus, I. burgundiae, on the basis of a specimen discovered in the quarries of the town of Sainte-Colombe, in Yonne, France. ^[50] Even before the taxon was described by Gaudry, the specimen, being one of the largest ichthyosaurs known at the time, led to it being presented at the 1889 Paris Exposition, the same exhibition for which the Eiffel Tower was built. After the end of the exhibition, the specimen was subsequently donated to the National Museum of Natural History in Paris, joining its collection on November 12, 1889, where it is still exhibited to this day. ^[51] Gaudry already proposed the name of I. burgundiae at the French Academy of Sciences in 1891, ^[52] but it was not until the following year that he published the first formal description of the taxon. ^[50] In 1996, McGowan attributed a number of specimens discovered in Germany to this species, but moved it there to the genus Temnodontosaurus. ^[53] In 1998, Maisch compared these specimens to the holotype of T. trigonodon, and suggested synonymizing T. burgundiae with the latter. ^[33] Maisch's opinion is followed by McGowan and Motani in 2003, considering T. burgundiae as a junior synonym of T. trigonodon, despite slight osteological differences. ^{[2] : 85, 87} The synonymy is however based only on German specimens, a new examination of the holotype specimen discovered in Sainte-Colombe having never been carried out due to its questionable state of conservation. ^[51]

NHMUK PV R43971, the holotype skull of T. risor

In 1974, McGowan described an additional species of Temnodontosaurus, T. risor, based on three skulls discovered at Lyme Regis, designating NHMUK PV R43971 as the holotype specimen. The specific name of this taxon comes from the Latin Risor, meaning "mocker". In his description, he justifies the distinction of this species via the larger orbits, the smaller maxillae and the curved snout. ^[4] In 1995, the same author carried out a more in-depth revision of the three specimens attributed to this taxon. He then discovered that the characteristics he had previously judged to be distinctive were in fact stages of growth, the three specimens representing juveniles of T. platyodon. ^[5]

Early depictions

An 1854 depiction of Temnodontosaurus in Crystal Palace Park

One of the earliest representations of Temnodontosaurus in paleoart is a life-size concrete sculpture created by Benjamin Waterhouse Hawkins between 1852 and 1854, ^[54] as part of the collection of sculptures of prehistoric animals on display at the Crystal Palace Park in London. ^[55] It is one of the three ichthyosaur sculptures exhibited in the park, the other two representing Ichthyosaurus and Leptonectes . Although the park is known for its obsolete or even false reconstructions of extinct animals, the sculptures depicting ichthyosaurs have the most elements still recognized as valid. These recognized features include smooth, scaleless skin, a fin at the end of the tail, and large eyes. Hawkins also reconstructed the facial features of these three ichthyosaurs based on those of whales and dolphins, which is still recognized as reasonable given their strong morphological similarities. Discoveries and reconstructions subsequent to those at the Crystal Palace add to this the presence of a dorsal fin, a caudal fin with two crescent-shaped lobes as well as a reconstruction of the skin on the basis of most well-preserved fossils. ^[55]

Many elements of these reconstructions still remain obsolete, such as the eyes and the flippers which are reconstructed by the shape of their bones, namely the sclerotic rings and the phalanges. Although Owen suggested the still viable hypothesis that the scleral rings served to protect the eye, it is highly unlikely that the eyes of ichthyosaurs would have looked as shown in the carvings, given that the scleral rings are located under the eyelids. The flippers were faithfully reconstructed by Hawkins based on Owen's misinterpretation of the phalanges as scales. The park's ichthyosaurs are depicted as crawling in shallow water, reflecting the ancient hypothesis that they came to the shores to sleep or to breed. Additionally, their tails are shown to be eel-like and having a great degree of flexibility. However, the three ichthyosaurs actually had a fairly variable degree of flexibility. Two of the three taxa shown, i. e. Temnodontosaurus and Leptonectes, were found to have much more flexible tails than that of Ichthyosaurus, the latter having a tuna-like morphology. This way of reconstructing the tail of ichthyosaurs as similar to those of eels is not an error specific to Hawkins, being the norm in reconstructions dating from the 19th century. ^[55]

Description

Temnodontosaurus, like other ichthyosaurs, had a long, thin snout, large eye sockets, and a tail fluke that was supported by vertebrae in the lower half. Ichthyosaurs were superficially similar to dolphins and had flippers rather than legs, and most (except for early species) had dorsal fins. ^[56] Although the colour of Temnodontosaurus is unknown, at least some ichthyosaurs may have been uniformly dark-coloured in life, which is evidenced by the discovery of high concentrations of eumelanin pigments in the preserved skin of an early ichthyosaur fossil. ^[57]

Size

Size of T. platyodon compared to a human

Temnodontosaurus is one of the largest ichthyosaurs identified to date, although the species which belong to it are not as imposing as Triassic forms like Shonisaurus , Himalayasaurus , Cymbospondylus or Ichthyotitan . ^{[9] [2] : 83  [58]} It nevertheless represents the largest known ichthyosaur of the parvipelvian group. ^[59] Based on different specimens, the species T. platyodon, T. trigonodon and T. crassimanus have a body size which is estimated to be around 9 m (30 ft) long. ^{[4] [9] [53] [2] : 83  [35] : 49, 51, 101, 104  [6]} The ‘Rutland Sea Dragon’, a possible specimen of T. trigonodon discovered in January 2021 in the Rutland Water, near Oakham, is estimated to be slightly over 10 m (33 ft) long. ^[25] Skull size varies between these three species. The largest known skulls of T. trigonodon and T. platyodon are 1.8 m (5 ft 11 in) ^{[53] [2] : 83} to 1.9 m (6 ft 3 in) long, ^{[60] : 152–153} respectively. Although incomplete, the holotype specimen of T. crassimanus would have had a skull estimated to be around 1 m (3 ft 3 in) long. ^{[35] : 49, 51, 101, 104  [6]} No body length estimates for T. zetlandicus and T. nuertingensis have currently been given. However, the measurement of their skull, reaching respectively 1 to 1.3 m (3 ft 3 in to 4 ft 3 in) in length, suggests that they are smaller representatives when compared to the three species previously mentioned. ^{[8] [7]}

Individual bones suggest that Temnodontosaurus may have grown to a larger size. ^[59] In his extensive revision published in 1922, von Huene described a series of very imposing vertebrae from from the collections of the Banz Abbey Museum, Germany, the largest of them measuring 22 cm (8.7 in) high. ^[40] In 1996, McGowan nominally assigned the specimen to Temnodontosaurus, although without specific assignment. Based on SMNS 50000, a nearly complete skeleton of T. trigonodon, the author estimated the size of Banz's specimen at 16 m (52 ft) long, ^[53] as Huene initially suggested. ^[40] However, the estimate he proposes turns out to be exaggerated, given that the source of its size is incorrect based on the actual measurements of the specimen SMNS 50000, which is of a shorter length. ^[59]

Morphology

Life restoration of T. platyodon

The forefins and hindfins of Temnodontosaurus were of roughly the same length and were rather narrow and elongated. This characteristic is unlike other post-Triassic ichthyosaurs such as the thunnosaurians, which had forefins at least twice the length of their hindfins. It was different from other post-Triassic ichthyosaurs like Ichthyosaurus, possessing an unreduced, tripartite pelvic girdle and having only three primary digits with one postaxial accessory digit. Like other ichthyosaurs, the fins exhibited strong hyperphalangy, but the fins were not involved in body propulsion; only the tail was used as the main propulsive force for movement, although it had a weak tail bend at an angle of less than 35°. Its caudal fin has variously been described as either lunate or semi-lunate; it was made of two lobes, in which the lower lobe was skeletally supported whereas the upper lobe was unsupported. The proximal elements of the fin formed a mosaic pattern, while the more distal elements were relatively round. It also had a triangular dorsal fin and had two notches on the fin's anterior margin; the paired fins were used to steer and stabilize the animal while swimming instead of paddling or propulsion devices. ^{[9] [1] [61]} It had roughly less than 90 vertebrae, and the axis and atlas of the vertebrae were fused together, serving as stabilization during swimming. T. trigonodon possessed unicipital ribs near the sacral region and the bicipital ribs more anteriorly, which helped to increase flexibility while swimming. ^[62]

Like other ichthyosaurs, Temnodontosaurus likely had high visual capacity and used vision as its primary sense while hunting. Temnodontosaurus had the largest eyes of any ichthyosaur and of any animal measured. The largest eyes measured belonged to the species T. platyodon. Despite the enormous size of its eyes, Temnodontosaurus had blind spots directly above its head due to the angle at which its eyes were pointed. The eyes of Temnodontosaurus had sclerotic rings, hypothesized to have provided the eyes with rigidity. The sclerotic rings of T. platyodon were at least 25 cm in diameter. ^{[9] [63]}

The head of Temnodontosaurus had a long robust snout with an antorbital constriction. It also had an elongated maxilla, a long cheek region, and a long postorbital segment. The carotid foramen in the basisphenoid in the skull was paired and was separated by the parasphenoid. The parasphenoid had a processus cultriformis. The skull of T. platyodon measured about 1.5 m (4.9 ft) long, while T. eurycephalus had a shorter rostrum and a deeper skull compared to other species, perhaps serving to help crush prey. T. platyodon and T. trigadon had a very long snout that was slightly curved on its dorsal side and ventrally curved, respectively. It also had many pointed conical teeth that were set in continuous grooves, rather than having individual sockets. This form of tooth implantation is known as aulacodonty. Its teeth typically had two or three carinae; notably, T. eurycephalus possessed bulbous roots, while T. nuertingensis had no canine or bulbous roots. ^{[9] [5] [1] [61]}

Classification

Life restoration of T. platyodon

The majority of the currently recognized species of Temnodontosaurus were originally described as species of Ichthyosaurus, ^{[16] [27] [38] [39]} before the type species T. platyodon was moved to a separate genus in 1889 by Lydekker. ^{[19] : xi} In 1974, McGowan established the family Temnodontosauridae, ^[4] to which it is still the only genus recognized. ^[7] Temnodontosaurus is one of the most basal post-Triassic ichthyosaurs. ^{[41] : 155} In the first major phylogenetic revision of ichthyosaurs, carried out in 1999 by Motani, Temnodontosaurus is placed in the Parvipelvia clade. ^[64] It is this specific group of ichthyosaurs that includes all of the "fish-shaped" representatives, with the more basal ichthyosaurs having more elongated body plans. ^[56] In 2000, Paul Martin Sander  [ de ] erected a new clade within this subgroup, which he named Neoichthyosauria. ^[61] This clade notably brings together Temnodontosaurus, Suevoleviathan , Leptonectidae and Thunnosauria, the latter including all of the ichthyosaurs that lived until the Cretaceous. ^{[1] : 98} For reasons of classification convenience, McGowan and Motani established the superfamily Temnodontosauroidea in 2003. ^{[2] : 83} In their phylogenetic revision published in 2016, Ji and colleagues classify Leptonectidae within this proposed superfamily, recovering Temnodontosaurus as the latter's sister taxon. ^[65] However, other classifications clearly do not follow this model, preferring to stick to the definition of Neoichthyosauria as previously mentioned. ^{[66] [67] [7]}

For several decades, Temnodontosaurus was a taxon whose monophyly was rarely questioned. ^[7] The current diagnostic of the genus was first established in the revision made by McGowan in 1974 based on some cranial and postcranial characteristics. ^[4] However, as the cranial features of aquatic tetrapods are strongly influenced by convergent evolution, this does not seem ideal for establishing a stable taxonomy. ^[7] Thus, since the late 1990s, many authors, including McGowan himself, have advocated that Temnodontosaurus needs to be revised. ^{[53] [61] [6]} Additionally, numerous recent phylogenetic analyzes showing that the genus as currently defined is polyphyletic, with some historically assigned species being unrelated each other. ^{[67] [7]} Thus, pending future studies, Temnodontosaurus is currently seen as a wastebasket taxon including some large, more or less related neoichthyosaurians dating from the Lower Jurassic. ^{[6] [7] [25]} In the last major study investigating the taxonomy of this genus, having been carried out by Laboury et al. (2022), only four species appear to form a monophyletic grouping, namely T. platyodon, T. trigonodon, T. zetlandicus and T. nuertingensis. ^[7]

Below, a simplified cladogram based on a Bayesian analysis conducted by Laboury et al. (2022): ^[7]

Parvipelvia	Hudsonelpidia brevirostris Macgowania janiceps Ichthyosauridae Temnodontosaurus azerguensis Leptonectidae Temnodontosaurus crassimanus Suevoleviathan integer Temnodontosaurus eurycephalus Temnodontosaurus nuertigensis Temnodontosaurus zetlandicus Temnodontosaurus platyodon Temnodontosaurus trigonodon Malawania anachronus Hauffiopteryx Baracromia

Paleobiology

With their dolphin-like bodies, ichthyosaurs were better adapted to their aquatic environment than any other group of marine reptiles. ^[61] They were viviparous that gave birth to live young and were likely incapable of leaving the water. As homeotherms ("warm-blooded") with high metabolic rates, ichthyosaurs would have been active swimmers. ^[68] Jurassic and Cretaceous ichthyosaurs, including Temnodontosaurus, had evolved a thunniform method of swimming rather than the anguilliform (undulating or eel-like) methods of earlier species. ^[61] Temnodontosaurus, particularly the species T. trigonodon, is quite flexible in morphology for a parvipelvian, using its imposing flippers to maneuver under water. ^[62]

Ichthyosaurs have the largest eyes of any known vertebrates, with Temnodontosaurus having the largest identified. The sclerotic rings in their eyes would have served to resist aquatic pressures. The eyes of ichthyosaurs like those of Temnodontosaurus would have a great visual capacity via the high number of photoreceptor cells. ^{[69] [63]} In addition to good eyesight, the enlarged olfactory region of the brain indicates that ichthyosaurs had a sensitive sense of smell. ^[70]

Diet and feeding

Paleontologists generally agree that Temnodontosaurus was likely an active predator of a variety of other marine animals. Fauna hunted by the genus include bony fish, cephalopods, and aquatic reptiles, including even other ichthyosaurs. ^{[9] [53] [71] [72]} The skeletal anatomy of Temnodontosaurus suggests that it may have been an ambush predator. ^{[48] [62]} A particular skeleton of T. trigonodon (SMNS 50000) preserves in its stomach the remains of three juvenile Stenopterygius accompanied by a large number of cephalopod hooks. ^{[71] [72]} This proves that the animal was indeed an apex predator, but its diet consisted mainly of molluscs, with the large number of undigested hooks being compressed into a large gastric mass. ^[71]

Paleoecology

Map of the world during the Early Jurassic, at around 195 million years ago

Western Europe

In Europe, Temnodontosaurus is mainly known from fossils dating from the various stages of the Lower Jurassic of England, Germany, France and Luxembourg, ^{[4] [53] [2] : 87  [7]} with nevertheless some more or less fragmentary specimens having been reported in Belgium, ^{[2] : 83  [73]} in Italy, ^[74] and in Switzerland. ^[75]

Chile

While Temnodontosaurus was historically known only from Europe, a fragmentary specimen was discovered in 1988 in the Atacama Desert, Chile. This specimen, consisting of fragmentary remains of the jaws and catalogued since as SGO.PV.324, was later rediscovered in 2016 in the collections of the National Museum of Natural History of Chile in Santiago, and first described in 2020. It comes more precisely from the volcanic beds of the La Negra Formation, dating from the Early Jurassic. The presence of ammonites potentially belonging to the genera Arnioceras and Paracoronicera indicates that the formation probably dates from the Sinemurian. The fossil record of vertebrates discovered in what is now northern Chile is currently very thin, but remains quite similar to that found in Europe. At that time, northern Chile was submerged by the southeastern part of the ancient superocean Panthalassa. Among the vertebrates identified are leptolepids, actinopterygians already present in Europe. Apart from Temnodontosaurus itself, the marine reptiles identified include thalattosuchians and undetermined plesiosaurs. The presence of these taxa in northern Chile could be explained by an interfaunal exchange between Thetys and Panthalassa, although other evidence suggesting this remains thin. ^[76]

See also

• List of ichthyosaurs
• Timeline of ichthyosaur research

Notes

1. The exact year of the find is uncertain, as sources diverge towards a date variously given between 1809 and 1811. ^[10]
2. In the only detailed description of Temnodontosaurus by Lydekker, the taxon is nevertheless always referred to as I. platyodon. ^{[19] : 1126}
3. Since a study carried out by McGowan in 1996, this taxon is today known as Leptonectes , Leptopterygius being an already preoccupied junior synonym of a genus of actinopterygians belonging to the family Gobiesocidae. ^[32]

References

1. Michael W. Maisch; Andreas T. Matzke (2000). "The Ichthyosauria". Stuttgarter Beiträge zur Naturkunde, Serie B. 298: 1–159.
2. Christopher McGowan; Ryosuke Motani (2003). Hans-Dieter Sues (ed.). Handbook of Paleoherpetology Part 8: Ichthyopterygia. Munich: Verlag Dr. Friedrich Pfeil. ISBN   3-89937-007-4.
3. Oliver Perry Hay (1902). Bibliography and catalogue of the fossil Vertebrata of North America. Bulletin of the United States Geological Survey. Washington: Government Printing Office. p. 462. OCLC   799712116.
4. Christopher McGowan (1974). "A revision of the Longipinnate Ichthyosaurs of the Lower Jurassic of England, with descriptions of two new species (Reptilia: Ichthyosauria)". Life Sciences Contributions, Royal Ontario Museum. 97: 1–37.
5. Chris McGowan (1995). "Temnodontosaurus risor is a juvenile of T. platyodon (Reptilia: Ichthyosauria)". Journal of Vertebrate Paleontology . 14 (4): 472–479. Bibcode:1995JVPal..14..472M. doi:10.1080/02724634.1995.10011573. JSTOR   4523589. S2CID   84993853.
6. Emily J. Swaby; Dean R. Lomax (2021). "A revision of Temnodontosaurus crassimanus (Reptilia: Ichthyosauria) from the Lower Jurassic (Toarcian) of Whitby, Yorkshire, UK". Historical Biology . 31 (11): 2715–2731. Bibcode:2021HBio...33.2715S. doi:10.1080/08912963.2020.1826469. S2CID   225116735.
7. Antoine Laboury; Rebecca F. Bennion; Ben Thuy; Robert Weis; Valentin Fischer (2022). "Anatomy and phylogenetic relationships of Temnodontosaurus zetlandicus (Reptilia: Ichthyosauria)". Zoological Journal of the Linnean Society . 195 (1): 172–194. doi: 10.1093/zoolinnean/zlab118 . S2CID   261942356.
8. Michael W. Maisch; Axel Hungerbühler (1997). "Revision of Temnodontosaurus nuertingensis (v. Huene, 1931), a large ichthyosaur from the Lower Pliensbachian (Lower Jurassic) of Nürtingen, South Western Germany". Stuttgarter Beiträge zur Naturkunde Serie B (Geologie und Paläontologie). 248: 1–11.
9. Christopher McGowan (1992). "The Sea Dragons" . Dinosaurs, spitfires, and sea dragons. Cambridge: Harvard University Press. p. 246. ISBN   978-0-6742-0770-7.
10. Hugh Torrens (1995). "Mary Anning (1799–1847) of Lyme; 'the greatest fossilist the world ever knew'". The British Journal for the History of Science . 25 (3): 257–284. doi: 10.1017/S0007087400033161 . JSTOR   4027645. S2CID   145269086.
11. Deborah Cadbury (2000). "Epilogue" . The Dinosaur Hunters : A True Story of Scientific Rivalry and the Discovery of the Prehistoric World. London: Fourth Estate. pp. 323–324. ISBN   978-1-85702-963-5.
12. Everard Home (1814). "Some account of the fossil remains of an animal more nearly allied to fishes than any of the other classes of animals". Philosophical Transactions of the Royal Society of London . 104: 571–577. doi: 10.1098/rstl.1814.0029 . S2CID   111132066.
13. Everard Home (1819). "Reasons for giving the name Proteo-Saurus to the fossil skeleton which has been described". Philosophical Transactions of the Royal Society of London . 109: 212–216. doi: 10.1098/rstl.1819.0016 . S2CID   109406664.
14. Henry T. De la Beche; William D. Conybeare (1821). "Notice of the discovery of a new Fossil Animal, forming a link between the Ichthyosaurus and Crocodile, together with general remarks on the Osteology of the Ichthyosaurus". Transactions of the Geological Society of London . 2. 5: 559–594. doi: 10.1144/transgsla.5.559 . S2CID   84634727.
15. Henry T. De la Beche (1822). "Remarks on the Geology of the South Coast of England, from Bridport Harbour, Dorset, to Babbacombe Bay, Devon". Transactions of the Geological Society of London . 2. 1 (1): 40–47. doi: 10.1144/transgslb.1.1.40 . S2CID   128881944.
16. William D. Conybeare (1822). "Additional Notices on the Fossil Genera Ichthyosaurus and Plesiosaurus". Transactions of the Geological Society of London . 2. 1 (1): 103–123. doi: 10.1144/transgslb.1.1.103 . S2CID   129545314.
17. Henry G. Liddell; Robert Scott (1980) [1871]. A Greek-English Lexicon (abridged ed.). Oxford: Oxford University Press. ISBN   978-0-19-910207-5.
18. Richard Owen (1881). A monograph of the fossil Reptilia of the Liassic formations, Part III, Ichthyopterygia. London: Printed for the Palæontographical Society. pp. 83–134. OCLC   6930920.
19. Henry A. Nicholson; Richard Lydekker (1889). "Palaeozoology; Vertebrata". A manual of palaeontology for the use of students with a general introduction on the principles of palaeontology. Vol. 2. Edinburgh and London: William Blackwood and Sons. pp. 889–1464. OCLC   7919973.
20. Ryosuke Motani (2000). "Rulers of the Jurassic Seas". Scientific American . 283 (6): 52–59. Bibcode:2000SciAm.283f..52M. doi:10.1038/scientificamerican1200-52. PMID   11103459. S2CID   5246133.
21. Ivan R. Schwab (2002). "My, what big eyes you have . . ". The British Journal of Ophthalmology . 86 (2): 130. doi: 10.1136/bjo.86.2.130 . ISSN   0007-1161. PMC   1771016 . PMID   11855367.
22. Christopher McGowan (1972). "The Distinction between Latipinnate and Longipinnate Ichthyosaurs". Life Science Contributions, Royal Ontario Museum. 20: 1–12.
23. Christopher McGowan (1972). "Evolutionary Trends in Longipinnate Ichthyosaurs, with Particular Reference to the Skull and Fore Fin". Life Science Contributions, Royal Ontario Museum. 83: 1–38.
24. Arthur Smith Woodward; Charles Davies Sherborn (1890). A catalogue of British fossil Vertebrata. London: Dulau & Co. p. 240.
25. Nigel R. Larkin; Dean R. Lomax; Mark Evans; Emma Nicholls; Steven Dey; Ian Boomer; Philip Copestake; Paul Bown; James B. Riding; Darren Withers; Joseph Davis (2023). "Excavating the 'Rutland Sea Dragon': The largest ichthyosaur skeleton ever found in the UK (Whitby Mudstone Formation, Toarcian, Lower Jurassic)". Proceedings of the Geologists' Association . 134 (5–6): 627–640. Bibcode:2023PrGA..134..627L. doi: 10.1016/j.pgeola.2023.09.003 . S2CID   262205225.
26. Mark R. Graham; Jonathan D. Radley; Dean R. Lomax (2020). "An overlooked contributor to palaeontology—the preparator Richard Hall (b. 1839) and his work on an armoured dinosaur and a giant sea dragon". Geological Curator. 11 (4): 275–280. doi: 10.55468/gc1497 . hdl: 10141/622882 . S2CID   251988522.
27. Carl von Theodori (1843). "Über einen kolossalen Ichthyosaurus trigonodon" [About the colossal Ichthyosaurus trigonodon]. Gelehrte Anzeigen der Königlich Bayerischen Akademie der Wissenschaften (in German). 16 (2): 906–911.
28. Carl von Theodori (1854). Beschreibung des kolossalen Ichthyosaurus trigonodon in der Lokal-PetrefaktenSammlung zu Banz, nebst synoptischer Darstellung der übrigen Ichthyosaurus-Arten in derselben [Description of the colossal Ichthyosaurus trigonodon in the local petrefact collection at Banz, along with a synoptic representation of the other Ichthyosaurus species in the same] (in German). Munich: Georg Franz. pp. 1–81. OCLC   191977419.
29. Richard Lydekker (1889). Catalogue of the fossil Reptilia and Amphibia in the British Museum (Natural history). Part II. London: Printed by order of the Trustees. p. 105-112. OCLC   491763833.
30. Richard Lydekker (1890). Catalogue of the fossil Reptilia and Amphibia in the British Museum (Natural history). Part IV. London: Printed by order of the Trustees. p. 271. OCLC   491763858.
31. Friedrich von Huene (1931). "Neue studien über Ichthyosaurier aus Holzmaden". Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft (in German). 42: 345–382.
32. Chris McGowan (1996). "The taxonomic status of Leptopterygius Huene, 1922 (Reptilia: Ichthyosauria)". Canadian Journal of Earth Sciences . 33 (3): 439–443. Bibcode:1996CaJES..33..439M. doi:10.1139/e96-033. S2CID   129507468.
33. Michael W. Maisch (1998). "Kurze Übersicht der Ichthyosaurier des Posidoniaschiefers mit Bemerkungen zur Taxonomie der Stenopterygiidae und Temnodontosauridae" [Brief overview of the ichthyosaurs of the Posidonia Shale with comments on the taxonomy of the Stenopterygiidae and Temnodontosauridae]. Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen (in German). 209 (3): 401–431. doi:10.1127/njgpa/209/1998/401.
34. Rebecca F. Bennion; Erin E. Maxwell; Olivier Lambert; Valentin Fischer (2023). "Craniodental ecomorphology of the large Jurassic ichthyosaurian Temnodontosaurus". Journal of Anatomy . 244 (1): 22–41. doi:10.1111/joa.13939. hdl: 2268/305672 . PMC  10734653. PMID   37591692.
35. Emily J. Swaby (2020). A revision of Temnodontosaurus crassimanus (Reptilia: Ichthyosauria) from the Lower Jurassic (Toarcian) of Whitby, Yorkshire, UK (PDF) (MPhil). University of Manchester.
36. Sidney Melmore (1930). "A description of the type-specimen of Ichthyosaurus crassimanus, Blake (Owen MS.)". Annals and Magazine of Natural History . 10. 6 (35): 615–619. doi:10.1080/00222933008673261. S2CID   87629216.
37. John Phillips; Robert Etheridge. John Murray (ed.). Illustrations of the Geology of Yorkshire: or, a Description of the Strata and Organic Remains. Part I. The Yorkshire Coast. p. 272.
38. John F. Blake, "Order Ichthyopterygia", in Ralph Tate; John F. Blake (eds.), The Yorkshire Lias, London: John Van Voorst, pp. 253–254, OCLC   1159757532
39. Harry G. Seeley (1880). "On the skull of an Ichthyosaurus from the Lias of Whitby, apparently indicating a new species (I. zetlandicus, Seeley), preserved in the Woodwardian Museum of the University of Cambridge". Quarterly Journal of the Geological Society . 36 (1–4): 635–647. Bibcode:1880QJGS...36..635S. doi: 10.1144/GSL.JGS.1880.036.01-04.47 . S2CID   129081597.
40. Friedrich von Huene (1922). Die Ichthyosaurier des Lias und ihre Zusammenhänge[The Ichthyosaurs of the Lias and their connections] (in German). Berlin: Verlag von Gebrüder Borntraeger. OCLC   19870277.
41. Michael W. Maisch (2010). "Phylogeny, systematics, and origin of the Ichthyosauria – the state of the art" (PDF). Palaeodiversity. 3: 151–214.
42. Friedrich von Huene (1931). "Neue Ichthyosaurier aus Württemberg" [New ichthyosaurs from Württemberg]. Neues Jahrbuch für Mineralogie Geologie und Paläontologie Beilage-Band, Abteilung B (in German). 65: 305–320.
43. Friedrich von Huene (1930). "Über zwei Fälle von Nearthrose bei fossilen Ichthyosauriern" [About two cases of neararthrosis in fossil ichthyosaurs]. Anatomischer Anzeiger (in German). 70 (5): 108–109.
44. 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.
45. Oskar Kuhn (1939). "Ein Ichthyosaurier aus dem oberen Lias gamma von Fallstein im nördlichen Harzvorland" [An ichthyosaur from the Upper Lias gamma of Fallstein in the northern Harz foothills]. Nova Acta Academiae Caesareae Leopoldino Carolinae N.F. Halle (in German). 7: 135–138.
46. Christopher McGowan (1979). "A Revision of the Lower Jurassic Ichthyosaurs of Germany with Descriptions of two new Species". Palaeontographica A. 166 (4–6): 93–135. S2CID   203112602.
47. Serge Elmi; Louis Rulleau (1991). "Le Toarcien des carrières Lafarge (Bas-Beaujolais, France): Cadre biostratigraphique de référence pour la région lyonnaise" [The Toarcian of the Lafarge quarries (Bas-Beaujolais, France): Biostratigraphic reference framework for the Lyon region]. Geobios (in French). 24 (3): 315–331. Bibcode:1991Geobi..24..315E. doi:10.1016/S0016-6995(09)90011-0. S2CID   129637111.
48. Jeremy E. Martin; Valentin Fischer; Peggy Vincent; 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 . S2CID   130554998.
49. Darren Naish (January 30, 2014). "Cant get me enough of that sweet, sweet Temnodontosaurus". Scientific American Blog Network . Archived from the original on June 3, 2024.
50. Albert Gaudry (1892). "L'Ichthyosaurus burgundiae" [The Ichthyosaurus burgundiae]. Bulletin de la Société d'Histoire naturelle d'Autun (in French). 5: 365–372.
51. Arnaud Brignon (2018). "L'industrie du ciment de Vassy et son rôle dans les découvertes des vertébrés toarciens de l'Avallonnais" [The cement industry of Vassy and its role in the discoveries of Toarcian vertebrates of Avallonnais]. Fossiles, Revue française de Paléontologie (in French). 34: 21–50.
52. Albert Gaudry (1891). "L'ichthyosaure de Sainte-Colombe" [The ichthyosaur of Sainte-Colombe]. Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences (in French). 113: 169–172.
53. Chris McGowan (1996). "Giant ichthyosaurs of the Early Jurassic". Canadian Journal of Earth Sciences . 33 (7): 1011–1021. Bibcode:1996CaJES..33.1011M. doi:10.1139/e96-077. S2CID   128700808.
54. Emily Osterloff. "The world's first dinosaur park: what the Victorians got right and wrong". Archived from the original on April 18, 2021.
55. Mark Witton (April 30, 2019). "The science of the Crystal Palace Dinosaurs, part 1: marine reptiles, Dicynodon and "labyrinthodons"". Mark Witton.com. Archived from the original on May 30, 2024.
56. Ryan Marek (2015). "Fossil Focus: Ichthyosaurs". Palaeontology Online. 5: 8. Archived from the original on 18 January 2021. Retrieved 13 June 2020.
57. Johan Lindgren; Peter Sjövall; Ryan M. Carney; Per Uvdal; Johan A. Gren; Gareth Dyke; Bo Pagh Schultz; Matthew D. Shawkey; Kenneth R. Barnes; Michael J. Polcyn (2014). "Skin pigmentation provides evidence of convergent melanism in extinct marine reptiles". Nature . 506 (7489): 484–488. Bibcode:2014Natur.506..484L. doi:10.1038/nature12899. PMID   24402224. S2CID   4468035.
58. Dean R. Lomax; Paul de la Salle; Marcello Perillo; Justin Reynolds; Ruby Reynolds; James F. Waldron (2024). "The last giants: New evidence for giant Late Triassic (Rhaetian) ichthyosaurs from the UK". PLOS ONE . 19 (4): e0300289. Bibcode:2024PLoSO..1900289L. doi: 10.1371/journal.pone.0300289 . PMC   11023487 . PMID   38630678.
59. 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 . S2CID   13714078.
60. Judy A. Massare; Dean R. Lomax; Matt Williams; Cindy Howells (2024). "A catalog of the Lower Lias ichthyosaurs in the Charles Moore Collection". Paludicola. 14 (4): 141–193.
61. P. Martin Sander (2000). "Ichthyosauria: their diversity, distribution, and phylogeny". Paläontologische Zeitschrift . 74 (1): 1–35. Bibcode:2000PalZ...74....1S. doi:10.1007/BF02987949. S2CID   85352593.
62. Emily A. Buchholtz (2001). "Swimming styles in Jurassic ichthyosaurs" (PDF). Journal of Vertebrate Paleontology . 21 (1): 61–73. doi:10.1671/0272-4634(2001)021[0061:SSIJI]2.0.CO;2. JSTOR   4524172. S2CID   85925883.
63. Ryosuke Motani (2005). "Evolution of Fish-Shaped Reptiles (reptilia: Ichthyopterygia) in Their Physical Environments and Constraints" (PDF). Annual Review of Earth and Planetary Sciences . 33: 395–420. Bibcode:2005AREPS..33..395M. doi:10.1146/annurev.earth.33.092203.122707. S2CID   54742104. Archived from the original (PDF) on 2018-12-23.
64. Ryosuke Motani (1999). "Phylogeny of the Ichthyopterygia" (PDF). Journal of Vertebrate Paleontology . 19 (3): 472–495. Bibcode:1999JVPal..19..473M. doi:10.1080/02724634.1999.10011160. JSTOR   4524011. S2CID   84536507. Archived from the original (PDF) on April 15, 2012.
65. Cheng Ji; Da-Yong Jiang; Ryosuke Motani; Olivier Rieppel; Wei-Cheng Hao; Zuo-Yu Sun (2016). "Phylogeny of the Ichthyopterygia incorporating recent discoveries from South China". Journal of Vertebrate Paleontology . 36 (1): e1025956. Bibcode:2016JVPal..36E5956J. doi:10.1080/02724634.2015.1025956. S2CID   85621052.
66. Philippa M. Thorne; Marcello Ruta; Michael J. Benton (2011). "Resetting the evolution of marine reptiles at the Triassic-Jurassic boundary". Proceedings of the National Academy of Sciences . 108 (20): 8339–8344. Bibcode:2011PNAS..108.8339T. doi: 10.1073/pnas.1018959108 . PMC   3100925 . PMID   21536898.
67. Benjamin C. Moon (2017). "A new phylogeny of ichthyosaurs (Reptilia: Diapsida)" (PDF). Journal of Systematic Palaeontology . 17 (2): 129–155. Bibcode:2019JSPal..17..129M. doi:10.1080/14772019.2017.1394922. S2CID   90912678.
68. Yasuhisa Nakajima; Alexandra Houssaye; Hideki Endo (2014). "Osteohistology of the Early Triassic ichthyopterygian reptile Utatsusaurus hataii: Implications for early ichthyosaur biology". Acta Palaeontologica Polonica . 59 (2): 343–352. doi: 10.4202/app.2012.0045 . S2CID   54932051.
69. Ryosuke Motani; Bruce M. Rothschild; William Wahl (1999). "Large eyeballs in diving ichthyosaurs" (PDF). Nature . 402 (6763): 747. Bibcode:1999Natur.402..747M. doi:10.1038/45435. ISSN   1476-4687. S2CID   5432366. Archived from the original (PDF) on 2017-01-18.
70. Ryan D. Marek; Benjamin C. Moon; Matt Williams; Michael J. Benton (2015). "The skull and endocranium of a Lower Jurassic ichthyosaur based on digital reconstructions". Palaeontology . 58 (4): 1–20. Bibcode:2015Palgy..58..723M. doi: 10.1111/pala.12174 . S2CID   131581009.
71. Ronald Böttcher (1989). "Über die Nahrung eines Leptopterygius (Ichthyosauria, Reptilia) aus dem süddeutschen Posidonienschiefer (Unterer Jura) mit Bemerkungen über den Magen der Ichthyosaurier" [On the diet of a Leptopterygius (Ichthyosaurıa, Reptilia) from the south German Posidonia Shales (Lower Jurassic) with remarks on the stomach of ichthyosaurs]. Stuttgarter Beiträge zur Naturkunde, Serie B (in German). 155: 1–19.
72. Detlev Thies; Rolf B. Hauff (2013). "A Speiballen from the Lower Jurassic Posidonia Shale of South Germany". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 267 (1): 117–124. doi:10.1127/0077-7749/2012/0301. S2CID   56085177.
73. Pascal Godefroit (1993). "Les grands ichthyosaures sinémuriens d'Arlon" [The large Sinemurian ichthyosaurs of Arlon](PDF). Bulletin de l'Institut Royal des Sciences Naturelles de Belgique (in French). 63: 25–71.
74. Gianni Insacco; Alfio Alessandro Chiarenza; Andrea Cau (2014). "Temnodontosaurus and Stenopterygius (Diapsida: Ichthyosauria) specimens in the Comiso Natural History Museum (Sicily, Italy)". Natura Rerum. 3 (1): 1–12.
75. Christian Klug; Timur Sivgin; Feiko Miedema; Beat Scheffold; Achim G. Reisdorf; Iwan Stössel; Erin E. Maxwell; Torsten M. Scheyer (2024). "Swiss ichthyosaurs: a review". Swiss Journal of Palaeontology . 143 (1). 31. Bibcode:2024SwJP..143...31K. doi: 10.1186/s13358-024-00327-4 . PMC   11366730 . PMID   39229570.
76. Rodrigo A. Otero; Patricio Sepúlveda (2020). "First temnodontosaurid (Ichthyosauria, Parvipelvia) from the Lower Jurassic of the Atacama Desert, northern Chile" (PDF). Journal of South American Earth Sciences . 98. 102459. Bibcode:2020JSAES..9802459O. doi:10.1016/j.jsames.2019.102459. S2CID   214318136.

External links

Paleontological videos

• Attenborough, David (7 January 2019). "Meet a Jurassic Killer: Temnodontosaurus". Nature on PBS . Archived from the original on 29 May 2024 – via YouTube.