Ichthyosauria Fossil range: Middle Triassic - Late Cretaceous
Ichthyosauria, Holzmaden, Museum Wiesbaden
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Sauropsida Subclass: Diapsida? Superorder: Ichthyopterygia Order: Ichthyosauria Blainville, 1835
Families
Ichthyosauridae Leptonectidae Mixosauridae Ophthalmosauridae Shastasauridae Stenopterygiidae Teretocnemidae

Ichthyosaurs (Greek for 'fish lizard' - ιχθυς meaning 'fish' and σαυρος meaning 'lizard') were giant marine reptiles that resembled fish and dolphins. Ichthyosaurs thrived during much of the Mesozoic era; based on fossil evidence, they first appeared approximately 230 million years ago (Mya) and disappeared about 90 million years ago, about 25 million years before the dinosaurs became extinct. During the middle Triassic Period, ichthyosaurs evolved from as-yet unidentified land reptiles that moved back into the water, in a development parallel to that of modern-day dolphins and whales. They were particularly abundant in the Jurassic Period, until they were replaced as the top aquatic predators by plesiosaurs in the Cretaceous Period. They belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' - a designation introduced by Sir Richard Owen in 1840, although the term is now used more for the parent clade of the Ichthyosauria). The Middle Triassic (also known as Muschelkalk) is the second of three epochs of the Triassic period. ... Geography of the US in the Late Cretaceous Period Late Cretaceous (100mya - 65mya) refers to the second half of the Cretaceous Period, named after the famous white chalk cliffs of southern England, which date from this time. ... Image File history File links Fischsaurier_fg01. ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... For other uses, see Animal (disambiguation). ... Typical Classes See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... Clades Subclass Anapsida Subclass Diapsida Infraclass Lepidosauromorpha Infraclass Archosauromorpha Sauropsids are a diverse group of mostly egg-laying vertebrate animals. ... Classes Ichthyosauria Sauropterygia Lepidosauria Archosauria Diapsids (two arches) are a group of tetrapod animals that developed two holes (temporal fenestra) in each side their skulls, about 300 million years ago during the late Carboniferous period. ... Groups Utatsusaurus Parvinatator Eoichthyosauria Grippidae/Grippidia Ichthyosauria Ichthyopterygia (fish flippers) was a designation introduced by Sir Richard Owen in 1840 to designate the Jurassic Ichthyosaurs that were known at the time, but the term is now used more often for both true Ichthyosauria and their more primitive early and middle... Henri Marie Ducrotay de Blainville Henri Marie Ducrotay de Blainville (September 12, 1777 - May 1, 1850) was a French zoologist and anatomist. ... | Come and take it, slogan of the Texas Revolution 1835 was a common year starting on Thursday (see link for calendar). ... The hierarchy of scientific classification In biological classification, family (Latin: familia, plural familiae) is a rank, or a taxon in that rank. ... Groups Cymbospondylus Mixosauridae Merriamosauria Shastasauridae/Shastasauria Euichthyosauria Parvipelvia Leptonectidae Thunnosauria Stenopterygidae Ichthyosauridae Ichthyosaurs (Greek for fish lizards) were giant marine reptiles that resemble a dolphin with teeth (see convergent evolution). ... Genera ?Chaohusaurus Cymbospondylus Shonisaurus ?Himalayasaurus Shastasaurus The shastasaurs were an early group of ichthyosaurs, living 230-210 million years ago, in the Triassic period. ... Stenopterygius is an extinct genus of diapsid reptile belonging to the ichthyosaur order of fish-like aquatic reptiles. ... Orders  Crocodilia - Crocodilians scary crocodiles. ... Mesozoic Era is one of three geologic eras of the Phanerozoic eon. ... For other uses, see Fossil (disambiguation). ... Mega-annum, usually abbreviated as Ma, is a unit of time equal to one million years. ... For other uses of mya, see mya (disambiguation). ... Orders Saurischia    Sauropodomorpha    Theropoda Ornithischia Dinosaurs are giant reptiles that dominated the terrestrial ecosystem for most of their 165-million year existence. ... The Triassic is a geologic period that extends from about 251 ± 0. ... A geologic period is a subdivision of geologic time that divides an era into smaller timeframes. ... For other uses, see Dolphin (disambiguation). ... This article is about the animal. ... The Jurassic Period is a major unit of the geologic timescale that extends from about 199. ... Families Cimoliasauridae Cryptoclididae Elasmosauridae Plesiosauridae Polycotylidae Plesiosaurs (pronounced ) (Greek: plesios meaning near or close to and sauros meaning lizard) were carnivorous aquatic (mostly marine) reptiles. ... // The Cretaceous Period (pronounced ) is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... Sir Richard Owen KCB (July 20, 1804–December 18, 1892) was an English biologist, comparative anatomist and palaeontologist. ...

Description

Ichthyosaurs averaged 2 to 4 meters in length (although a few were smaller, and some species grew much larger), with a porpoise-like head and a long, toothed snout. Built for speed, like modern tuna, some ichthyosaurs appear also to have been deep divers, like some modern whales (Motani, 2000). It has been estimated that ichthyosaurs could swim at speeds up to 40 km/h (25 mph).^{[citation needed]} Similar to modern cetaceans such as whales and dolphins, they were air-breathing and also were viviparous (some adult fossils have even been found containing fetuses). Although they were reptiles and descended from egg-laying ancestors, viviparity is not as unexpected as it first appears. All air-breathing marine creatures must either come ashore to lay eggs, like turtles and some sea snakes, or else give birth to live young in surface waters, like whales and dolphins. Given their streamlined bodies, heavily adapted for fast swimming, it would have been difficult for ichthyosaurs to scramble successfully onto land to lay eggs. Genera Neophocaena Phocoena - Harbor porpoise Phocoenoides - Dalls porpoise The porpoises are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. ... For other uses, see Tuna (disambiguation). ... Suborders Mysticeti Odontoceti Archaeoceti (extinct) (see text for families) The order Cetacea (IPA: , L. cetus, whale) includes whales, dolphins and porpoises. ... A viviparous animal is an animal employing vivipary, a method of reproduction in which the embryo develops inside the body of the mother from which it gains nourishment, and not from an egg. ... Solid blue lines and broken grey lines represent the streamlines. ...

Historical Ichthyosaur illustration, 1863.

According to weight estimates by Ryosuke Motani [1] a 2.4 meter (8 ft) Stenopterygius weighed around 163 to 168 kg (360 to 370 lb), whilst a 4.0 meter (13 ft) Ophthalmosaurus icenicus weighed 930 to 950 kg (about a ton). Image File history File links Ichthyosaur_-_Project_Gutenberg_eText_16033. ... Image File history File links Ichthyosaur_-_Project_Gutenberg_eText_16033. ... Stenopterygius is an extinct genus of diapsid reptile belonging to the ichthyosaur order of fish-like aquatic reptiles. ... Had extraordinarily large eyes. ...

Although ichthyosaurs looked like fish, they were not. Biologist Stephen Jay Gould said the ichthyosaur was his favorite example of convergent evolution, were similarities of structure are analogous not homologous, for this group: Stephen Jay Gould (September 10, 1941 – May 20, 2002) was an American paleontologist, evolutionary biologist, and historian of science. ... In evolutionary biology, convergent evolution is the process whereby organisms not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. ... An analogy is a comparison between two different things, in order to highlight some form of similarity. ... In biology, homology is any similarity between structures that is due to their shared ancestry. ...

Drawing of an Ichthyosaur skeleton.

Fossil of a young Ichthyosaur from the zoological museum of Hamburg.

Ichthyosaur 'paddle' (Charmouth Heritage Coast Centre).

converged so strongly on fishes that it actually evolved a dorsal fin and tail in just the right place and with just the right hydrological design. These structures are all the more remarkable because they evolved from nothing — the ancestral terrestrial reptile had no hump on its back or blade on its tail to serve as a precursor. Drawing of an Ichthyosaur skeleton, scanned from a copyright free source. ... Drawing of an Ichthyosaur skeleton, scanned from a copyright free source. ... Image File history File linksMetadata Download high resolution version (1600x437, 67 KB) Summary en: Fossil of a young Ichthyosaur from the zoological museum of Hamburg, photographed on September 2004, author: soebe de: Versteinerung eines jungen Ichthyosauriers im Zoologischen Museum in Hamburg, fotografiert im September 2004 von soebe. ... Image File history File linksMetadata Download high resolution version (1600x437, 67 KB) Summary en: Fossil of a young Ichthyosaur from the zoological museum of Hamburg, photographed on September 2004, author: soebe de: Versteinerung eines jungen Ichthyosauriers im Zoologischen Museum in Hamburg, fotografiert im September 2004 von soebe. ... Image File history File links Download high resolution version (2440x867, 1296 KB) Summary Photographer: User:Ballista Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Image File history File links Download high resolution version (2440x867, 1296 KB) Summary Photographer: User:Ballista Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Scelidosaurus reconstruction at the Centre Charmouth Heritage Coast Centre is based in the upstairs floor of a long-disused cement factory on the foreshore of Charmouth in Dorset, England. ... Dorsal fin of an orca A dorsal fin is a fin located on the backs of fishes, whales, dolphins, and porpoises, as well as the (extinct) ichthyosaurs. ...

Temnodontosaurus platyodon

In fact the earliest reconstructions of ichthyosaurs omitted the dorsal fin, which had no hard skeletal structure, until finely-preserved specimens recovered in the 1890s from the Holzmaden lagerstätten in Germany revealed traces of the fin. Unique conditions permitted the preservation of soft tissue impressions. The 1890s were sometimes referred to as the Mauve Decade, because William Henry Perkins aniline dye allowed the widespread use of that colour in fashion, and also as the Gay Nineties, under the then-current usage of the word gay which referred simply to merriment and frivolity, with no... Holzmaden is a town in Germany near Württemberg containing rich layers of well preserved fossils (or Lagerstätten) of the Jurassic period. ... Lagerstätten (German, singular: Lagerstätte, literally: place(s) of storage or resting place(s)) are sedimentary deposits that exhibit extraordinary fossil richness or completeness. ...

Ichthyosaurs had fin-like limbs, which were possibly used for stabilisation and directional control, rather than propulsion, which would have come from the large shark-like tail. The tail was bi-lobed, with the lower lobe being supported by the caudal vertebral column, which was "kinked" ventrally to follow the contours of the ventral lobe.

Apart from the obvious similarities to fish, the ichthyosaurs also shared parallel developmental features with dolphins. This gave them a broadly similar appearance, possibly implied similar activity and presumably placed them broadly in a similar ecological niche. For other uses, see Dolphin (disambiguation). ...

For their food, many of the fish-shaped ichthyosaurs relied heavily on ancient cephalopod kin of squids called belemnites. Some early ichthyosaurs had teeth adapted for crushing shellfish. They also most likely fed on fish, and a few of the larger species had heavy jaws and teeth that indicated they fed on smaller reptiles. Ichthyosaurs ranged so widely in size, and survived for so long, that they are likely to have had a wide range of prey. Typical ichthyosaurs have very large eyes, protected within a bony ring, suggesting that they may have hunted at night. Orders Subclass Nautiloidea †Plectronocerida †Ellesmerocerida †Actinocerida †Pseudorthocerida †Endocerida †Tarphycerida †Oncocerida †Discosorida Nautilida †Orthocerida †Ascocerida †Bactritida Subclass †Ammonoidea †Goniatitida †Ceratitida †Ammonitida Subclass Coleoidea †Belemnoidea †Aulacocerida †Belemnitida †Hematitida †Phragmoteuthida Neocoleoidea (most living cephalopods) ?†Boletzkyida Sepiida Sepiolida Spirulida Teuthida Octopoda Vampyromorphida The cephalopods (Greek plural (kephalópoda); head-foot) are the mollusc class... For other uses, see Squid (disambiguation). ... Extinct Orders Aulacocerida Phragmoteuthida Belemnitida Diplobelida Belemnoteuthina Belemnites (or belemnoids) are an extinct group of marine cephalopod, very similar in many ways to the modern squid and closely related to the modern cuttlefish. ... Cooked mussels Shellfish is a term used to describe shelled molluscs and crustaceans used as food. ...

History of discoveries

Ichthyosaur mounted skeleton (Charmouth Heritage Coast Centre).

The genus had first been described in 1699 from fossil fragments discovered in Wales. Image File history File links Download high resolution version (2375x819, 1132 KB) Summary Photographer: User:Ballista Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Image File history File links Download high resolution version (2375x819, 1132 KB) Summary Photographer: User:Ballista Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Scelidosaurus reconstruction at the Centre Charmouth Heritage Coast Centre is based in the upstairs floor of a long-disused cement factory on the foreshore of Charmouth in Dorset, England. ... Events January 26 - Treaty of Karlowitz signed March 30 - the tenth Sikh Master, Guru Gobind Singh created the Khalsa. ... This article is about the country. ...

The first fossil vertebrae were published twice in 1708 as tangible mementos of the Universal Deluge. The first complete ichthyosaur fossil was found in 1811 by Mary Anning in Lyme Regis, along what is now called the Jurassic Coast. She subsequently discovered three separate species. For other uses, see Fossil (disambiguation). ... A diagram of a thoracic vertebra. ... // Events March 23 - James Francis Edward Stuart lands at the Firth of Forth July 1 - Tewoflos becomes Emperor of Ethiopia September 28 - Peter the Great defeats the Swedes at the Battle of Lesnaya Kandahar conquered by Mir Wais In Masuria one third of the population die during the plague J... This article is about great floods. ... For the US Federal Agent designation, see Special agent. ... Mary Anning (May 21, 1799 – March 9, 1847) was an early British fossil collector and paleontologist. ... , Lyme Regis (IPA: ) is a coastal town in West Dorset, England, situated 25 miles west of Dorchester and 25 miles east of Exeter. ... The Jurassic Coast is a World Heritage Site on the English Channel coast of southern England. ...

In 1905, the Saurian Expedition led by John C. Merriam of the University of California and financed by Annie Alexander, found 25 specimens in central Nevada, which during the Triassic was under a shallow ocean. Several of the specimens are now in the collection of the University of California Museum of Paleontology. Other specimens are embedded in the rock and visible at Berlin-Ichthyosaur State Park in Nye County. In 1977 the Triassic ichthyosaur Shonisaurus became the State Fossil of Nevada. Nevada is the only state to possess a complete skeleton, 55 ft (17 m) of this extinct marine reptile. In 1992, Canadian ichthyologist Dr. Elizabeth Nicholls (Curator of Marine Reptiles at the Royal Tyrrell {"tur ell"} Museum) uncovered the largest fossil specimen ever, a 23m (75')-long example. For other uses, see 1905 (disambiguation). ... The Saurian Expedition of 1905 was a noted paleontological research mission in northern Nevada in the United States. ... John Campbell Merriam (October 20, 1869 - October 30, 1945) was an American paleontologist. ... Berkeley Davis Irvine Los Angeles Merced Riverside San Diego Santa Barbara Santa Cruz UC Office of the President in Oakland The University of California (UC) is a public university system in the state of California. ... Annie Montague Alexander (1867-1950) was an American financier and paleontological collector. ... This article is about the U.S. State of Nevada. ... Berkeley Davis Irvine Los Angeles Merced Riverside San Diego Santa Barbara Santa Cruz UC Office of the President in Oakland The University of California (UC) is a public university system in the state of California. ... Berlin-Icthyosaur St. ... Nye County is a county located in the U.S. state of Nevada. ... Also: 1977 (album) by Ash. ... It has been suggested that List of U.S. state dinosaurs be merged into this article or section. ...

Evolutionary history

A skeleton at the American Museum of Natural HIstory.

The earliest ichthyosaurs, looking more like finned lizards than the familiar fish or dolphin forms, are known from the Early and Early-Middle (Olenekian and Anisian) Triassic strata of Canada, China, Japan, and Spitsbergen in Norway. These primitive forms included the genera Chaohusaurus, Grippia, and Utatsusaurus. There are many Museums of Natural History around the world, including: American Museum of Natural History, in New York City. ... Groups Utatsusaurus Parvinatator Eoichthyosauria Grippidae/Grippidia Ichthyosauria Ichthyopterygia (fish flippers) was a designation introduced by Sir Richard Owen in 1840 to designate the Jurassic Ichthyosaurs that were known at the time, but the term is now used more often for both true Ichthyosauria and their more primitive early and middle... The Olenekian (also known as the Yongningzhenian) is a stage of the Early Triassic epoch. ... In the geologic timescale, the Anisian is the age of the Middle Triassic epoch of the Triassic period of the Mesozoic era of the Fanerozoic eon that is comprehended between 245 million and 237 million years ago, approximatedly. ... The Triassic is a geologic period that extends from about 251 ± 0. ... Spitsbergen (formerly known as West Spitsbergen) is a Norwegian island, the largest island in the Svalbard archipelago, situated in the Arctic Ocean. ... Utatsusaurus is the earliest-known form of an icthyosaur, inhabiting the Scythian stage of the middle Triassic period. ...

Grippia longirostris from early Triassic of Spitsbergen

These very early proto-ichthyosaurs, which are now classified as Ichthyopterygia rather than as ichthyosaurs proper (Motani 1997, Motani et al. 1998), quickly gave rise to true ichthyosaurs sometime in the latest Early Triassic or earliest Middle Triassic. These later diversified into a variety of forms, including the sea-serpent like Cymbospondylus, which reached 10 meters, and smaller more typical forms like Mixosaurus. By the Late Triassic, ichthyosaurs consisted of both classic Shastasauria and more advanced, "dolphin"-like Euichthyosauria (Californosaurus, Toretocnemus) and Parvipelvia (Hudsonelpidia, Macgowania). Experts disagree over whether these represent an evolutionary continum, with the less specialised shastosaurs a paraphyletic grade that was evolving into the more advanced forms (Maisch and Matzke 2000), or whether the two were separate clades that evolved from a common ancestor earlier on (Nicholls and Manabe 2001). Groups Utatsusaurus Parvinatator Eoichthyosauria Grippidae/Grippidia Ichthyosauria Ichthyopterygia (fish flippers) was a designation introduced by Sir Richard Owen in 1840 to designate the Jurassic Ichthyosaurs that were known at the time, but the term is now used more often for both true Ichthyosauria and their more primitive early and middle... Cymbospondylus was an early Ichthyosaur that lived in the middle of the Triassic period. ... Mixosaurus is an extinct genus of diapsid reptile belonging to the ichthyosaur order. ... The Late Triassic (also known as Upper Triassic, or Keuper) is the third and final of three epochs of the Triassic period. ... Paraphyletic - Wikipedia /**/ @import /skins-1. ... A clade is a term belonging to the discipline of cladistics. ...

During the Carnian and Norian, shastosaurs reached huge sizes. Shonisaurus popularis, known from a number of specimens from the Carnian of Nevada, was 15 meters long. Norian shonisaurs are known from both sides of the Pacific. Himalayasaurus tibetensis and Tibetosaurus (probably a synonym) have been found in Tibet. These large (10 to 15 meters long) ichthyosaurs probably belong to the same genus as Shonisaurus (Motani et al, 1999; Lucas, 2001, pp.117-119). While the gigantic Shonisaurus sikanniensis, whose remains were found in the Pardonet formation of British Columbia by Elizabeth Nicholls, reached as much as 21 meters in length - the largest marine reptile known to date. The Carnian is a stage on the geologic time scale occuring from 228 +/- 2 to 216. ... The Norian Stage was a portion of the Triassic geological period. ... Shonisaurus popularis is the state fossil of Nevada. ... This article is about historical/cultural Tibet. ...

These giants (along with their smaller cousins) seemed to have disappeared at the end of the Norian. Rhaetian (latest Triassic) ichthyosaurs are known from England, and these are very similar to those of the Early Jurassic. Like the dinosaurs, the ichthyosaurs and their contemporaries the plesiosaurs survived the end-Triassic extinction event, and immediately diversified to fill the vacant ecological niches of the earliest Jurassic. The Rhaetian Stage is the most recent stage of the Late Triassic. ... Massive cliffs in Zion Canyon consist of Lower Jurassic formations, including (from bottom to top): the Wingate Sandstone, the Kayenta Formation, and the massive Navajo Sandstone. ...

A historical restoration of Ichthyosaurus by Heinrich Harder.

Platypterigius longmani

The Early Jurassic, like the Late Triassic, was the heyday of the ichthyosaurs, which are represented by four families and a variety of species, ranging from one to ten meters in length. Genera include Eurhinosaurus, Ichthyosaurus, Leptonectes, Stenopterygius, and the large predator Temnodontosaurus, along with the persistently primitive Suevoleviathan, which was little changed from its Norian ancestors. All these animals were streamlined, dolphin-like forms, although the more primitive animals were perhaps more elongated than the advanced and compact Stenopterygius and Ichthyosaurus. Image File history File links Download high-resolution version (826x448, 104 KB) Painting of the ichthyosaur Ichthyosaurus by Heinrich Harder. ... Image File history File links Download high-resolution version (826x448, 104 KB) Painting of the ichthyosaur Ichthyosaurus by Heinrich Harder. ... Image File history File linksMetadata Size of this preview: 763 × 599 pixelsFull resolution (900 × 707 pixel, file size: 59 KB, MIME type: image/jpeg) Platypterigius_longmani reconstruction autor - Bogdanov dmitrchel@mail. ... Image File history File linksMetadata Size of this preview: 763 × 599 pixelsFull resolution (900 × 707 pixel, file size: 59 KB, MIME type: image/jpeg) Platypterigius_longmani reconstruction autor - Bogdanov dmitrchel@mail. ... Groups Cymbospondylus Mixosauridae Merriamosauria Shastasauridae/Shastasauria Euichthyosauria Parvipelvia Leptonectidae Thunnosauria Stenopterygidae Ichthyosauridae Ichthyosaurs (Greek for fish lizards) were giant marine reptiles that resemble a dolphin with teeth (see convergent evolution). ... Temnodontosaurus was an ichthyosaur from the early Jurassic found in Europe (England & Germany) which grew to 9m. ... Stenopterygius is an extinct genus of diapsid reptile belonging to the ichthyosaur order of fish-like aquatic reptiles. ... Groups Cymbospondylus Mixosauridae Merriamosauria Shastasauridae/Shastasauria Euichthyosauria Parvipelvia Leptonectidae Thunnosauria Stenopterygidae Ichthyosauridae Ichthyosaurs (Greek for fish lizards) were giant marine reptiles that resemble a dolphin with teeth (see convergent evolution). ...

Ichthyosaurs were still common in the Middle Jurassic, but had now decreased in diversity. All belonged to the single clade Ophthalmosauria. Represented by the 4 meter long Ophthalmosaurus and related genera, they were very similar to Ichthyosaurus, and had attained a perfect "tear-drop" streamlined form. The eyes of Ophthalmosaurus were huge, and it is likely that these animals hunted in dim and deep water (Motani 2000). The Middle Jurassic, called the Dogger in the European system of classification, is the second epoch of the Jurassic period. ... Had extraordinarily large eyes. ...

Ichthyosaurs seemed to decrease in diversity even further with the Cretaceous. Only a single genus is known, Platypterygius, and although it had a worldwide distribution, there was little diversity species-wise. This last genus ichthyosaur became extinct during an extinction event early in the Late Cretaceous (Cenomanian-Turonian; as the pliosaurs). Interestingly, less hydrodynamically efficient animals like mosasaurs and long-necked plesiosaurs flourished. It could be that the ichthyosaurian over-specialisation was a contributing factor to their extinction, possibly being unable to 'keep up' with the fast swimming and highly evasive new teleost fishes, which had become dominant at this time, against which the sit-and-wait ambush strategies of the mosasaurs proved superior (Lingham-Soliar 1999). // The Cretaceous Period (pronounced ) is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... Subfamilies Mosasaurinae Plioplatecarpinae Tylosaurinae Mosasaurs (from Latin Mosa, the Meuse river where the fossils were first discovered + Greek sauros, lizard) were serpentine marine reptiles, more closely related to snakes than to monitor lizards (Lee 1997). ... Families Cimoliasauridae Cryptoclididae Elasmosauridae Plesiosauridae Polycotylidae Plesiosaurs (pronounced ) (Greek: plesios meaning near or close to and sauros meaning lizard) were carnivorous aquatic (mostly marine) reptiles. ... Superorders Osteoglossomorpha Elopomorpha Clupeomorpha Ostariophysi Protacanthopterygii Sternopterygii Cyclosquamata Scopelomorpha Lampridiomorpha Polymyxiomorpha Paracanthopterygii Polymyxiomorpha Acanthopterygii Teleostei is one of three infraclasses in class Actinopterygii, the ray-finned fishes. ...

Taxonomy of species

• Order ICHTHYOSAURIA
• Family Mixosauridae
• Suborder Merriamosauriformes
  • Guanlingsaurus
  • (unranked) Merriamosauria
    • Family Shastasauridae
    • Cymbospondylus
    • Infraorder Euichthyosauria ("true ichthyosaurs")
      • Family Teretocnemidae
      • (Unranked) Parvipelvia ("small pelves")
        • Macgovania
        • Hudsonelpidia
        • Suevoleviathan
        • Temnodontosaurus
        • Family Leptonectidae
        • Infraorder Thunnosauria ("tuna lizards")
          • Family Stenopterygiidae
          • Family Ichthyosauridae
          • Family Ophthalmosauridae

Genera ?Chaohusaurus Cymbospondylus Shonisaurus ?Himalayasaurus Shastasaurus The shastasaurs were an early group of ichthyosaurs, living 230-210 million years ago, in the Triassic period. ... Cymbospondylus was an early Ichthyosaur that lived in the middle of the Triassic period. ... Temnodontosaurus was an ichthyosaur from the early Jurassic found in Europe (England & Germany) which grew to 9m. ... Stenopterygius is an extinct genus of diapsid reptile belonging to the ichthyosaur order of fish-like aquatic reptiles. ... Groups Cymbospondylus Mixosauridae Merriamosauria Shastasauridae/Shastasauria Euichthyosauria Parvipelvia Leptonectidae Thunnosauria Stenopterygidae Ichthyosauridae Ichthyosaurs (Greek for fish lizards) were giant marine reptiles that resemble a dolphin with teeth (see convergent evolution). ...

In popular culture

• Ichthyosaurus is one of the prehistoric creatures mentioned in Jules Verne's book Journey to the Center of the Earth, in which it fights with a Plesiosaurus. However, in the book it is described as being much, much larger than it was in reality. Ironically, in the book the Ichthyosaurus wins the fight against the Plesiosaurus when the Plesiosaurus replaced the Ichthyosaurs as top marine predators in the Cretaceous period.

• The large aquatic monster from the video game Half-Life is named Ichthyosaur.

This article is about the French author. ... For other uses, see Journey to the Center of the Earth (disambiguation). ... Species (type)  ? (jr. ... // The Cretaceous Period (pronounced ) is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ...

References

Scientific American is a popular-science magazine, published (first weekly and later monthly) since August 28, 1845, making it the oldest continuously published magazine in the United States. ...

External links

Wikimedia Commons has media related to:

Ichthyosauria

• USMP Berkeley's ichthyosaur introduction
• Ryosuke Motani's detailed Ichthyosaur homepage, with vivid graphics
• Eureptilia: Ichthyosauria - Palaeos
• Ichthyosauria - cladogram (Mikko's Phylogeny Archive)
• Hauff Museum, Germany - exhibiting the finds of Holzmaden