Eustreptospondylus (/juːˌstrɛptoʊspɒnˈdaɪləs/ yoo-STREPT-o-spon-DY-ləs; meaning "true Streptospondylus") is a genus of megalosaurid theropod dinosaur, from the Oxfordian stage of the Late Jurassic period (some time between 163 and 154 million years ago) in southern England, at a time when Europe was a series of scattered islands (due to tectonic movement at the time which raised the sea-bed and flooded the lowland).
|Mounted holotype skeleton|
Magnosaurus oxoniensis (Walker, 1964) Rauhut 2003
The main specimen of Eustreptospondylus was not fully grown, and according to an estimate by Paul in 1988 was about 4.63 metres (15.2 ft) long and weighed about 218 kilograms (481 lb). Various estimates suggest that Eustreptospondylus was an "average-sized" theropod, with a hypothetical adult length of around 6 metres (20 ft), and a mass of 0.5 tonnes (0.49 long tons; 0.55 short tons).
The skull of Eustreptospondylus has a rather pointed snout in side view, with a large horizontally oriented nostril. There is no lacrimal horn. The skull roof is relatively thick. Oblique grooves in the jaw joints caused the gape of the mouth to be widened when the lower jaws were opened. These jaws at the front are rather tall and wide. No teeth have been preserved in either the upper or lower jaws, but the size of its toothsockets proves that the third tooth of the lower jaw was enlarged. Though not keeled, the front dorsal vertebrae have paired hypapophyses at their undersides, just as with Streptospondylus altdorfensis.
Sadleir et al. (2008) established several traits that distinguish Eustreptospondylus from its direct relatives. In the corner of the lacrimal a shallow depression is present, which is pierced by a smaller foramen. The descending branch of the postorbital has a groove in its outer rear corner. The outer side of the squamosal has a well-developed drooping flange covering, in side view, the upper rear part of the lateral temporal fenestra. The tenth neck vertebra has a clear depression on its front underside. The neck and dorsal vertebrae are not keeled. In 2012 Matthew Carrano added to these traits. The peduncle of the ilium to which the pubic bone is attached, is as transversely wide as it is long from front to rear. With the rear blade of the ilium, the lower edge of the outer blade side is turned upwards to an almost horizontal position, creating and denuding over its total length a bone surface, the "brevis shelf", forming the internal face of the inner blade side — this shelf with dinosaurs functions as an attachment area for a tail muscle, the Musculus caudofemoralis brevis.
Sadleir also found additional traits proving that Eustreptospondylus differed from Magnosaurus nethercombensis in more than a single detail. The interdental plates reinforcing the back of the teeth are longer from front to rear than they are tall; with M. nethercombensis the opposite is true. Seen from above, the pubic bone forms transversely a more narrow part of the lower rim of the hip joint. Seen from behind, the upper part of the inner side of the thighbone is straight. The cnemial crest of the upper shinbone has no ridge running to the front and below, on its outer side.
In 1870, workers at the Summertown Brick Pit, just north of Oxford, England, found the skeleton of a theropod. The remains were acquired by the local bookseller James Parker, who brought them to the attention of Oxford Professor John Phillips. Phillips described the bones in 1871, but did not name them. At the time, the remains represented the most complete skeleton of a large theropod ever found. Eustreptospondylus is still the most complete of any large Jurassic European theropod. In 1890, the skeleton was bought by Oxford University, and Arthur Smith Woodward examined it and referred it to Megalosaurus bucklandi. In 1905 and 1906 Baron Franz Nopcsa reassigned the skeleton to the species, Streptospondylus cuvieri, which had been first described by Sir Richard Owen in 1842, based on a now lost vertebra from the Bathonian stage of the Jurassic period. The reason for this assignment was that the type species Streptospondylus altdorfensis from France, was a clearly related form, and Nopcsa decided to subsume all British material of this nature under a single Streptospondylus species, for which then the name S. cuvieri could not be avoided. The assignment of a rather complete find to a species based on very poor remains was troublesome. This was compounded by German palaeontologist Friedrich von Huene, who sometime referred to the specimen as Streptospondylus cuvieri and at other times considered it a species of Megalosaurus: Megalosaurus cuvieri.
In 1964, Alick Donald Walker clarified matters by erecting a separate genus and species for the Oxford specimen: Eustreptospondylus oxoniensis. The genus name Eustreptospondylus, was intended to mean "true Streptospondylus". Streptospondylus means "turned vertebra", and is derived from the Greek words streptos (στρεπτος) meaning "reversed" and spondylus (σπονδυλος), a reference to the fact that its dorsal vertebrae were opisthocoelous, in contrast to the typical procoelous vertebrae of crocodiles. The specific name "oxoniensis", refers to its provenance from Oxford.
The holotype, OUM J13558, was recovered by W. Parker from claystone in a marine layer of the Stewartby Member of the Oxford Clay Formation, which dates to the Callovian stage of the Jurassic period, approximately 162 million years ago. It consists of a rather complete skeleton, with a skull which is missing elements including the nasal bones, the jugals, the rear ends of the lower jaws, the lower arms and the end of the tail. It represents a subadult individual. The only other specimen ever referred to Eustreptospondylus oxoniensis is OUMNH J.29775, a left ilium. The holotype was fully prepared and exhibited in 1924, in a rather erect position. In the early twenty-first century a new display changed this to a horizontal position of the body.
In 2000, Oliver Walter Mischa Rauhut found that only minor differences in the hip bones — a more upward extending fusion of the "feet" of the pubic bones — make Eustreptospondylus different from a previously known megalosaurid called Magnosaurus, and in 2003 he proposed that they should be the same genus, which would make the full species name Magnosaurus oxoniensis. In 2010, Gregory S. Paul considered the species identical to Streptospondylus altdorfensis.
The first detailed description of the Eustreptospondylus material was in 1906 by Nopcsa. A modern description was published in 2008 by Rudyard Sadleir e.a. In 1964, Walker also named a second species of Eustreptospondylus: Eustreptospondylus divesensis, based on a French find. In 1977 this became the separate genus Piveteausaurus.
In 1964, Walker assigned Eustreptrospondylus to the Megalosauridae, which was historically included in a paraphyletic "Carnosauria", though sometimes a separate Eustreptospondylidae was recognised. Today Eustreptospondylus is commonly considered a member of the Eustreptospondylinae, clade within the Megalosauridae.
Eustreptospondylus, like many other theropods, fed on smaller dinosaurs and pterosaurs, or scavenged the carcasses of fishes, marine reptiles, and other dinosaurs. It might have foraged on shorelines for carcasses and marine life.
Eustreptospondylus is known from a fossil from on an island, at a time when Europe consisted mostly of archipelagos. This suggests that it might have been able to swim short distances. Eustreptospondylus has been considered a good swimmer, strong enough to swim from island to island like the modern day Komodo dragon. Not all palaeontologists agree with the swimming hypothesis. The opposing theories hold that the fossil of Eustreptospondylus was either swept out to sea during a flood after the animal died on the mainland, or it was carried to the ocean after it died in a river.
Eustreptospondylus has been portrayed as a genus that suffered from insular dwarfism. In 2000, David Martill and Darren Naish pointed out that the portrayal of the animal as an island-dwelling dwarf species was caused by not realizing that the holotype specimen represented a subadult.
The year 1870 in science and technology involved some significant events, listed below.1964 in paleontology
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1964.Afrovenator
Afrovenator (; "African hunter") is a genus of megalosaurid theropod dinosaur from the middle Jurassic Period of northern Africa.Alick Walker
Alick Donald Walker (26 October 1925 – 4 December 1999) was a British palaeontologist, after whom the Alwalkeria genus of dinosaur is named.
He was born in Skirpenbeck, near York and attended Pocklington School from 1936 to 1943. He began a degree course in engineering at Cambridge, but dropped out in 1944. In 1948 he returned to university after national service, reading Geology at the University of Bristol. On graduation, he join the research group of Professor Stanley Westoll at the University of Newcastle upon Tyne, working on the fossil reptiles of the Late Triassic found in Elgin. He was appointed Lecturer in Geology in 1954, while working on his PhD.
The bony remains of the Elgin reptile fossils were poor, sometimes just indentations in rocks. Walker devised a new casting method to capture the anatomical information in these fossils, using PVC; many of the resulting casts are now in the National Museum of Scotland and the Natural History Museum. His early work was also notable for reclassifying and naming the English theropod dinosaurs Eustreptospondylus and Metriacanthosaurus.
In the late 1960s Walker studied the origin of crocodilians and of birds, which became controversial in 1972 with his publication of a paper in Nature arguing for a close relationship between sphenosuchian crocodylomorphs and birds. He later accepted that this hypothesis might be incorrect in a 1985 paper on Archaeopteryx.Callovian
In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 166.1 ± 4.0 Ma (million years ago) and 163.5 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian.Cetiosauriscus
Cetiosauriscus ( SEE-tee-oh-SOR-iss-kəs) is a genus of sauropod dinosaur that lived between 166 and 164 million years ago during the Callovian (Middle Jurassic Period) in what is now England. A herbivore, Cetiosauriscus had—for sauropod standards—a moderately long tail, and longer forelimbs, making them as long as its hindlimbs. It has been estimated as about 15 m (49 ft) long and between 4 and 10 t (3.9 and 9.8 long tons; 4.4 and 11.0 short tons) in weight.
The only known fossil that was later named Cetiosauriscus includes most of the rear half of a skeleton as well as a hindlimb (NHMUK R3078). Found in Cambridgeshire in the 1890s, it was described by Arthur Smith Woodward in 1905 as a new specimen of the species Cetiosaurus leedsi. This was changed in 1927, when Friedrich von Huene found NHMUK R3078 and the C. leedsi type specimen to be too different from Cetiosaurus, warranting its own genus, which he named Cetiosauriscus, meaning "Cetiosaurus-like". Cetiosauriscus leedsi was referred to the sauropod family Diplodocidae because of similarities in the tail and foot, and had the dubious or intermediate species "Cetiosauriscus" greppini, "C." longus, and "C." glymptonensis assigned to it. In 1980, Alan Charig named a new species of Cetiosauriscus for NHMUK R3078 because of the lack of comparable material to the type of C. leedsi; this species was named Cetiosauriscus stewarti. Because of the poor state of preservation of the Cetiosauriscus leedsi fossil, Charig sent a petition to the International Commission on Zoological Nomenclature to instead make C. stewarti the type species. Cetiosauriscus stewarti became the oldest confirmed diplodocid until a phylogenetic analysis published in 2003 instead found the species to belong to Mamenchisauridae, and followed by studies in 2005 and 2015 that found it outside Neosauropoda, while not a mamenchisaurid proper.
Cetiosauriscus was found in the marine deposits of the Oxford Clay Formation alongside many different invertebrate groups, marine ichthyosaurs, plesiosaurs and crocodylians, a single pterosaur, and various dinosaurs: the ankylosaur Sarcolestes, the stegosaurs Lexovisaurus and Loricatosaurus, the ornithopod Callovosaurus, as well as some unnamed taxa. The theropods Eustreptospondylus, Metriacanthosaurus and Megalosaurus are known from the formation, although probably not from the same level as Cetiosauriscus.Dubreuillosaurus
Dubreuillosaurus is a genus of carnivorous dinosaur from the middle Jurassic Period. It is a megalosaurid theropod. Its fossils were found in France. The only named species, Dubreuillosaurus valesdunensis, was originally described as a species of Poekilopleuron, Poekilopleuron? valesdunensis, which is still formally the type species of the genus. It was later renamed Dubreuillosaurus valesdunensis when, in 2005, Allain came to the conclusion that it was not part of the genus Poekilopleuron. Its type specimen, MNHN 1998-13, is only rivalled in the number of preserved elements in this group by that of Eustreptospondylus. Dubreuillosaurus is considered to be the sister species of Magnosaurus. It did not show signs of insular dwarfism even though it was uncovered on an island.Leshansaurus
Leshansaurus is a genus of theropod dinosaur from the Mid to Late Jurassic Dashanpu Formation of what is now China. It was described in 2009 by a team of Chinese paleontologists. The type species is Leshansaurus qianweiensis. Fossils of Leshansaurus were discovered in strata from the Shangshaximiao Formation, a formation rich in dinosaur fossils. Li et al. referred this taxon to Sinraptoridae – a group of carnosaurian theropods, but it may it belong to Megalosauridae instead.List of creatures in Primeval
The following is a complete list of creatures from the universe of ITV science fiction television series Primeval and also any spin-off media, including Primeval: New World ("PNW"). The series includes various imaginary species which are not native to the series setting, with some being prehistoric and others being futuristic. Various creatures were designed with some artistic license, for dramatic effect. A number of creatures from the Walking with... series were also reimagined for dramatic effect.
In 2007 Character Options announced they would create Primeval action figures, including both a flying Rex and a large plush toy Rex, Future Predators, Hesperornis and dodos.Magnosaurus
Magnosaurus (meaning 'large lizard') was a genus of basal tetanuran theropod dinosaur from the Middle Jurassic of England. It is based on fragmentary remains and has often been confused with or included in Megalosaurus.Megalosauridae
Megalosauridae is a monophyletic family of carnivorous theropod dinosaurs within the order Megalosauroidea, closely related to the family Spinosauridae. Some members of this family include Megalosaurus, Torvosaurus, Eustreptospondylus, and Afrovenator. Appearing in the Middle Jurassic, megalosaurids were among the first major radiation of large theropod dinosaurs, although they became extinct by the end of the Jurassic period. They were a relatively primitive group of basal tetanurans containing two main subfamilies, Megalosaurinae and Afrovenatorinae, along with the basal genus Eustreptospondylus, an unresolved taxon which differs from both subfamilies.The defining megalosaurid is Megalosaurus bucklandii, first named and described in 1824 by William Buckland after multiple finds in Stonesfield, Oxfordshire, UK. Megalosaurus was the first formally described dinosaur and was the basis for the establishment of the clade Dinosauria. It is also one of the largest known Middle Jurassic carnivorous dinosaurs, with the best-preserved femur at 805 mm and a proposed body mass of around 943 kg. Megalosauridae is recognized as a mainly European group of dinosaurs, based on fossils found in France and the UK. However, recent discoveries in Niger have led some to consider the range of the family. Megalosaurids appeared right before the split of the supercontinent Pangaea into Gondwana and Laurasia. These large theropods therefore may have dominated both halves of the world during the Jurassic.The family Megalosauridae was first defined by Thomas Huxley in 1869, yet it has been contested throughout history due to its role as a ‘waste-basket’ for many partially described dinosaurs or unidentified remains. In the early years of paleontology, most large theropods were grouped together and up to 48 species were included in the clade Megalosauria, the basal clade of Megalosauridae. Over time, most of these taxa were placed in other clades and the parameters of Megalosauridae were narrowed significantly. However, some controversy remains over whether Megalosauridae should be considered its own distinct group, and dinosaurs in this family remain some of the most problematic taxa in all Dinosauria. Some paleontologists, such as Paul Sereno in 2005, have disregarded the group due to its shaky foundation and lack of clarified phylogeny. However, recent research by Carrano, Benson, and Sampson has systematically analyzed all basal tetanurans and determined that Megalosauridae should exist as its own family.Megalosauroidea
Megalosauroidea (meaning 'great/big lizard forms') is a superfamily (or clade) of tetanuran theropod dinosaurs that lived from the Middle Jurassic to the Late Cretaceous period. The group is defined as Megalosaurus bucklandii and all taxa sharing a more recent common ancestor with it than with Allosaurus fragilis or Passer domesticus. Members of the group include Spinosaurus, Megalosaurus, and Torvosaurus.Metriacanthosauridae
Metriacanthosauridae is an extinct family of theropod dinosaurs that lived from the Middle Jurassic to the Early Cretaceous. When broken down into its Greek roots, it means "moderately-spined lizards". The family is split into two subgroups: Metriacanthosaurinae, which includes dinosaurs closely related to Metriacanthosaurus, and another group composed of the close relatives of Yangchuanosaurus. Metriacanthosaurids are considered carnosaurs, belonging to the Allosauroidea superfamily. The group includes species of large range in body size. Of their physical traits, most notable are their neural spines. Their fossils can be found mostly in the Northern hemisphere. Metriacanthosauridae is used as a senior synonym of Sinraptoridae.Oxford Clay
The Oxford Clay is a Jurassic marine sedimentary rock formation underlying much of southeast England, from as far west as Dorset and as far north as Yorkshire. The Oxford Clay Formation dates to the Jurassic, specifically, the Callovian and Oxfordian ages, and comprises two main facies. The lower facies comprises the Peterborough Member, a fossiliferous organic-rich mudstone. This facies and its rocks are commonly known as lower Oxford Clay. The upper facies comprises the middle Oxford Clay, the Stewartby Member, and the upper Oxford Clay, the Weymouth Member. The upper facies is a fossil poor assemblage of calcareous mudstones.
Oxford Clay appears at the surface around Oxford, Peterborough and Weymouth and is exposed in many quarries around these areas. The top of the Lower Oxford Clay shows a lithological change, where fissile shale changes to grey mudstone. The Middle and Upper Oxford Clays differ slightly, as they are separated by an argillaceous limestone in the South Midlands.
The Callovo-Oxfordian Clay also occurs in the Paris Basin (France) and it is a potential host formation to dispose of high-level radioactive waste in France.Piatnitzkysauridae
Piatnitzkysauridae is an extinct family of megalosauroid dinosaurs. It consists of three known dinosaur genera: Condorraptor, Marshosaurus, and Piatnitzkysaurus. The most complete and well known member of this family is Piatnitzkysaurus, which also gives the family its name.Piveteausaurus
Piveteausaurus (meaning "Jean Piveteau's lizard") is a genus of theropod dinosaur known from a partial skull discovered in the Middle Jurassic Marnes de Dives formation of Calvados, in northern France.Streptospondylus
Streptospondylus (meaning "reversed vertebra") is a genus of tetanuran theropod dinosaur known from the Late Jurassic period of France, 161 million years ago. It was a medium-sized predator.Walking with Dinosaurs
Walking with Dinosaurs is a six-part documentary television miniseries created by Tim Haines and produced by BBC Natural History Unit. The series first aired on the BBC in the United Kingdom in 1999 with narration by Kenneth Branagh. The series was subsequently aired in North America on the Discovery Channel in 2000, with Avery Brooks replacing Branagh. The programme explores ancient life of the Mesozoic Era, portraying dinosaurs and their contemporaries in the style of a traditional nature documentary.
Developed by Haines and producer Jasper James, Walking with Dinosaurs recreated extinct species through the combined use of computer-generated imagery and animatronics that were incorporated with live action footage shot at various locations. The Guinness Book of World Records reported that the series was the most expensive documentary series per minute ever produced. A re-edited version of Walking with Dinosaurs aired on Discovery Kids for the first season of Prehistoric Planet. It was made more appropriate for children by removing most of the graphic content and trimming down some footage to fit the run time.
The series received critical acclaim, winning two BAFTA Awards, three Emmy Awards and a Peabody Award in 2000. Walking with Dinosaurs began a franchise that was followed by two additional miniseries, several television specials, spin-offs, a live-theatrical show, and a feature film of the same name.Wiehenvenator
Wiehenvenator is a genus of predatory megalosaurid theropod dinosaur from the Middle Jurassic (Callovian) of Germany.