The Jurassic Period

BY

Paul Iacovella

Paul Iacovella/OLMC/yr4/2009

Plants • Horsetails were an important source of nutrition for plant-eating

dinosaurs. These primitive vascular plants were fast-growing and resilient (they could propagate using underground runners which a grazing dinosaur wouldn't eat). This meant that a hungry dinosaur could eat the plant without killing it, since the plant would regrow from the rhizome (the underground stem).Some other Jurassic plants included: Williamsonia (a cycadeoidphyte), Williamsoniella (a cycadeoid), and Caytonia (a Caytoniale, which led to the flowering plants)

Williamsonia sewardiana was a cycadeoidphyte (a bennettitalean). It had a long, thin, woody stem and simple leaves.

Leptocycas was a cycad, a primitive seed plant from the late Triassic period. It was a palm-like tree with a long, woody trunk and tough leaves. It lived in warm climates. This tree was about 4.8 ft (1.5 m) tall.

Pteridophytes are a group of primitive vascular plants that include Lycopods (club mosses), Sphenopsids (horsetails, shown left), and ferns (shown, right). These plants reproduce with spores that germinate only in moist areas; they also reproduce using rhizomes (underground stems). Pteridophytes evolved during the Devonian and were mostly low-growing during the Mesozoic Era. These fast-growing, resilient plants were a source of food for plant-eating dinosaurs that lived in moist areas.

Paul Iacovella/OLMC/yr4/2009

JURASSIC DINOSAURS

Allosaurus

This fierce two legged carnivore lived in the late Jurassic period. It inhabited the plants, and normally hunted alone . It would hunt in groups to tackle the largest prey. It was approximately 12 meters long, five meters high and up to three tonnes.

Here is a list of dinosaurs for you.

AllosaurusBrachiosaurusCamptosaurusDicraeosaurusJinfengopteryxKentrosaurusLamplughsauraMassopondylusNanosaurusOmiesaurusPanoplosaurusRazanandrongobeStegosaurusTazoudasaurusWallnhoferiaZigongosaurus

Brachiosaurus lived in the middle to late Jurassic period, about 156-145 million years ago, near the middle of the Mesozoic Era, the Age of Reptiles. Some dating estimates have Brachiosaurus surviving until 140 million years ago, during the dawn of the Cretaceous period.

Camptosaurus (meaning "bent lizard") was a plant-eater from the late Jurassic period (about 156 to 145 million years ago) that looked a lot like Iguanodon. It was a heavy ornithischian dinosaur that was about 16-23 feet (5-7 m) long and 3-4 feet (1 m) high at the hips, weighing roughly 2,200 pounds (1000 kg). It had a long snout, hundreds of teeth and a horny beak. Its legs were longer than its arms; it had four-toed feet and five-fingered arms, all with hooves. It could walk on two or four legs, it probably went on all four to graze for low-lying plants.

Dicraeosaurus had a large head with a relatively short and wide neck. It also lacked the whiplash tail that other diplodocids had. It was smaller, at only reached 41 feet (12 m) in length. It gets its name, which means two-forked lizard, from the spines that came from the vertebrae. They were not straight as in some members of the family. Each one was “Y” shaped, like a fork. These spines also provided muscle attachment points it lived in the late Jurassic period.

Eustreptospondylus ("well-curved vertebra", in reference to the arrangement of the spine in the original fossil) was a genus of megalosaurid dinosaurs from the Callovian stage of the Middle Jurassic period (165 to 161 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). The only known specimen of Eustreptospondylus may not be fully grown, and was about 4.63 metres (15.2 ft) long. It was carnivorous, bipedal and had a stiffened tail. It was a typical theropod, with powerful hind limbs, erect posture and small forelimbs.

Fruitadens is a genus of heterodontosaurid dinosaur . The name means "Fruita tooth", in reference to Fruita, Colorado (USA), where its fossils were first found. It is known from partial skulls and skeletons from at least four individuals of differing biological ages, found in Tithonian (Late Jurassic) rocks of the Morrison formation in Colorado. Fruitadens is the smallest known ornithischian dinosaur, with young adults estimated at 65 to 75 cm (26 to 30 in) in length and 0.5 to 0.75 kg (1.1 to 1.7 lb) in weight. It is interpreted as an omnivore and represents one of the latest-surviving heterodontosaurids

Paul Iacovella/OLMC/yr4/2009

Giraffatitan, meaning “giraffe titan", is a genus of sauropod dinosaur that lived during the late Jurassic (kimmeridgian-Tithonian stages). It was originally named as an African species of Brachiosaurus (B. brancai). One of the largest animals known to have walked the earth, it has become one of the most famous of all dinosaurs.

Heterodontosaurus (meaning "different toothed lizard") is a genus of small herbivorous dinosaur with prominent canine teeth which lived in the Early Jurassic of South Africa. It was similar to a hypsilophodont in shape, and ate plants, despite its canines.Heterodontosaurus is currently known from specimens of the SAFM (South African Museum) from South Africa. There are two known morphologies of this genus, the second of which is thought by some to represent a different species. The type species, H. tucki, is from the Upper Elliot Formation of the Hettangian age, around 199-196 million years ago.

Iguanodon (pronounced meaning "Iguana tooth") is a genus of ornithopod dinosaur that lived roughly halfway between the first of the swift bipedal hypsilophodontids and the ornithopods' culmination in the duck-billed dinosaurs. Many species of Iguanodon have been named, dating from the Kimmeridgian age of the Late Jurassic Period to the Cenomanian age of the Late Cretaceous Period from Asia, Europe, and North America. However, research in the first decade of the 2000s suggests that there is only one well-substantiated species: I. bernissartensis, that lived from the Barremian to the early Aptian (Early Cretaceous) in Europe, between about 130 and 120 million years ago. Iguanodon's most distinctive features were its large thumb spikes, which were possibly used for defence against predators and foraging for food.Discovered in 1822 and described three years later by English geologist Gideon Mantell, Iguanodon was the second dinosaur formally named, after Megalosaurus. Together with Megalosaurus and Hylaeosaurus, it was one of the three genera originally used to define Dinosauria. A large, bulky herbivore, Iguanodon is a member of Iguanodontia, along with the duck-billed hadrosaurs. The taxonomy of this genus continues to be a topic of study as new species are named or long-standing ones reassigned to other genera.

• Jinfengopteryx (from Jinfeng, 'golden phoenix', the queen of birds in Chinese folklore, and Ancient Greek πτερυξ pteryx, meaning 'feather') is a genus of 55 cm (2 ft) long maniraptoran dinosaur. It was found in the Qiaotou member of the Huajiying Formation of Hebei Province, China, and is therefore of uncertain age. The Huajiying Formation underlies the more well-known Early Cretaceous Yixian Formation, so the Formation is either Early Cretaceous or Late Jurassic. Jinfengopteryx was preserved with extensive impressions of pennaceous feathers, but it lacks flight feathers on its hind legs, which are present in related dinosaurs such as Pedopenna.[1]

• Size compared in with a human• Artist's impression• Jinfengopteryx is known from one specimen (number CAGS-IG-04-0801), a nearly complete articulated skeleton

with feather impressions. It also preserves several small, oval structures that are reddish yellow in color. These may be the remains of eggs, or nuts/seeds that the dinosaur had eaten.

Paul Iacovella/OLMC/yr4/2009

Kentrosaurus (meaning "pointed lizard"; pronounced /ˌkɛtrɵˈsɔrəs/ KEN-tro-SAWR-əs, from the Greek kentron/κεντρον, meaning "point" or "prickle", and sauros/σαυρος meaning 'lizard',[1] is a genus of stegosaurid dinosaur from the Late Jurassic of Tanzania, related to the better-known Stegosaurus of North America. Its fossils have been found in the Tendaguru Formation, dated to the Kimmeridgian stage, between about 155.7 ± 4 Ma and 150.8 ± 4 Ma (million years ago).This 4 meter long stegosaurian was described by in 1915. Like Stegosaurus, Kentrosaurus had a double row of plates running down its spine. The two differed in size, in the shape of their armour plating, and in their bodily flexibility, however. The bony plates gave way to spikes about mid-way along the spine. It also had spikes on its flanks.The ceratopsid dinosaur Centrosaurus from the late Cretaceous period derives its name from the same Ancient Greek words, but the initial letter has changed to a 'C' and is pronounced as a soft C to avoid confusion.

Lamplughsaura is a genus of saurischian dinosaur from the Sinemurian-age (Early Jurassic) Dharmaram Formation of India, between 196 to 190 million years ago. The type species is L. dharmaramensis. It is known from several partial skeletons of a large quadrupedal animal up to 10 meters (33 ft) long, and was either a basal sauropod or, less likely, a more basal sauropodomorph.[1]

• Massospondylus were one of the strangest dinosaurs to ever exist. They were herbivores. The word Massospondylus is pronounced like mas-o-spon-di-lus. Massospondylus was known to be lived in North America and Southern Africa during the late Triassic period to the Early Jurassic period which is about 200 million years ago. It is said to be a strange dinosaur because of the shape of its limbs and the body.

• The Nanosaurus (pronounced NAN-uh-SAWR-us) was one of the smaller dinosaurs to ever exist, standing just under two feet tall and four feet long. If these dinosaurs were around today, they would be about the size of an average dog, except the fact the were pretty much a giant lizard walking on their hind legs. Discovered by Othniel Charles Marsh in the 1877, not much information is known about them but they are very similar to what is now called the Othnielosaurus or Othnielia. Most people think of them as "The Tiny Dinosaur" because that is what they are referred to in most popular books. Believed to be a herbivore and also bipedal, they survived mostly on plants and shrubs and possibly bugs and small animals as well. Most of the fossils have been found in the Colorado area and parts of Wyoming which is not a huge area, where they actually all inhabited is unknown but it seems mostly around the western central North America . It is believed that the Nanosaurus lived 155 to 148 million years ago during the late Jurassic period.

Paul Iacovella/OLMC/yr4/2009

Omeisaurus is of the Sauropoda group. Partial fossils including a head have been found in Mount Emei , China . Even though the fossils have been in very good shape there seems to be a fair bit of identity problems with the dinosaur. Many are thinking that it is made from existing dinosaurs. Through a study in 1996 two scientists claim the Omeisaurus is actually from the family of Mamenchisaurus and particularly a Zigongosaurus. Also another issue with the identity problem is their was a major rumor that Omeisaurus had a club at the end of its tail despite Paleontologists never even found a fossil that showed evidence of this. Apparently one was found near the area that the Omeisaurus was found and they figured it belonged. Changes are a club would've been too heavy ended for this dinosaur and make it very off balance.The Omeisaurus long neck and round body just like many Sauropods. The only really unique feature was that its nostrils faced forward as opposed to other dinosaurs of the same group such as the Brachiosaurus.The Supersaurus was discovered/recognized in 1985 by Dr. Jim Jenson. The fossils were located in a rock formation in Colorado in 1972 alongside a Brachiosaurus, so at first it was believed to be the same dinosaur but years later the scientists found out it was two different dino's. The only parts of the fossils found are

the shoulder blade and some of the neck vertebrae, but the shoulder blade itself stood over six feet tall. It is estimated that the Supersaurus stood over 80 feet tall and 130 feet long. This dinosaur was part of the diplodocus family and lived during the late Jurassic period. It is also thought to be the biggest dinosaur of the diplodocus family. It also was a herbivore meaning it ate plants. Just recently a new Supersaurus fossil set has been found and is currently being excavated out of a rock bed in Wyoming . This dino was indigenous to North America. Oviraptor philoceratops was a little Mongolian theropod dinosaur named by Henry Fairfield Osborn in 1924. Its name is Latin for "egg thief", as it was fossilized on a pile of presumed Protoceratops eggs. However, it is now supposed that the eggs belonged to this genus itself, and that it was actually brooding its eggs, based on discoveries of a related animal called Citipati, named by Clark, Makovicky, and Barsbold in 2000. Oviraptor forms the basis of a collection called Oviraptoridae, named by Barsbold Rinchen in 1976. Barsbold then used the name to coin a group called Oviraptorosauria.   Oviraptor may have eaten eggs; however Barsbold R. in 1977 argued that the strength of its beak indicates that it could break the shells of mollusks such as clams, which are found in the same formation as Oviraptor. The idea of a crushing jaw was first proposed by H. F. Osborn, who noticed both a toothless beak in the original skull and the extension of several bones below the jaw from the palate would have made an "egg-piercing" tool. These bones, ectopterygoids, are not actually part of the egg-piercing structure, and what Osborn found was incorrect.  In the 1950s and 60s, however, and described in the 70s and 80s, several skulls of oviraptorids have been found which show that they really are egg-piercing bones, as part of the main upper jaw bone or maxilla, which converge in the center to form a pair of prongs. The rest of the bony palate, unlike all other dinosaurs, is extended below the jaw line and would have pressed into the space between the toothless lower jaws. A rhamphotheca, or the keratin forming the beaks of birds, enclosed the edges of upper and lower beaks and probably the palate, as proposed by Barsbold and Osborn.

Paul Iacovella/OLMC/yr4/2009

Panoplosaurus means armoured lizard and was one of the last known nodosaurids. Nodosaurs were herbivores that survived for 120 million years. They belonged to the armored ankylosaurian dinosaur group. The earliest nodosaurs originally appeared 185 million years ago in what was the Middle Jurassic period. Panoplosaurus arrived 100 million years later in the Late Cretaceous.Panoplosaurus lived in what is now North America; fossils have been located in Montana and Alberta. It was 5.5 to 7.5 metres (18 to 25 ft) long, around 2 metres (6.6 ft) tall, and would have weighed approximately 3.5 tonnes (3.9 short tons). It was heavily armoured, even by the standards of other nodosaurs, with bands of studded plates covering its back and tail, although the tail lacked the club found in the later ankylosaurs. Heavier, squares of bony armour covered the shoulders. The armour on the head was fused into a single helmet-like shield. []The animal had a relatively narrow snout, perhaps to aid in rooting about for low growing plants to eat. The forelegs were particularly heavy, and had attachments for large muscles, which may suggest that the animal would have been surprisingly maneuverable in life, possibly being able to make defensive charges like a modern rhinoceros

Paul Iacovella/OLMC/yr4/2009

Razanandrongobe (meaning "large ancestor lizard" in Malagasy) is a genus of carnivorous archosaurian reptile of uncertain affinities from the Middle Jurassic of Madagascar. It is based on MSNM V5770, a fragment of maxilla, the main tooth-bearing bone of the upper jaw, and several isolated teeth have also been assigned to it. The remains come from the Bathonian-age Isalo Illb rock unit of Mahajanga. The jaw fragment and teeth are similar to the representative bones of theropod dinosaurs and some types of crocodylomorphs, and the authors refrained from assigning the genus to either group. They interpreted the stout teeth as having been used for crushing bones.[1] The fragment suggests a considerable size for the species, comparable to that of Tyrannosaurus.

• Stegosaurus (pronounced /ˌstɛɡɵˈsɔrəs/) is a genus of stegosaurid armored dinosaur from the Late Jurassic period (late Kimmeridgian to Early Tithonian) in what is now western North America. In 2006, a specimen of Stegosaurus was announced from Portugal, showing that they were present in Europe as well. [1] Due to its distinctive tail spikes and plates, Stegosaurus is one of the most recognizable dinosaurs, along with Tyrannosaurus, Triceratops, and Apatosaurus. The name Stegosaurus means "roof-lizard" and is derived from the Greek στέγος-, stegos- ("roof") and σαῦρος, -sauros ("lizard").[2] At least three species have been identified in the upper Morrison Formation and are known from the remains of about 80 individuals. They lived some 150 to 145 million years ago, in an environment and time dominated by the giant sauropods Diplodocus, Camarasaurus, and Apatosaurus.A large, heavily built, herbivorous quadruped, Stegosaurus had a distinctive and unusual posture, with a heavily arched back, short forelimbs, head held low to the ground and a stiffened tail held high in the air. Its array of plates and spikes has been the subject of much speculation. The spikes were most likely used for defense, while the plates have also been proposed as a defensive mechanism, as well as having display and thermoregulatory (heat control) functions. Stegosaurus was the largest of all the stegosaurians (bigger than genera such as Kentrosaurus and Huayangosaurus) and, although roughly bus-sized, it nonetheless shared many anatomical features (including the tail spines and plates) with the other stegosaurian genera

Paul Iacovella/OLMC/yr4/2009

Tazoudasaurus is a genus of vulcanodontid sauropod dinosaur hailing from the Early Jurassic Toundoute overthrust beds located in the High Moroccan Atlas Mountains. The remains, consisting of a partial adult skeleton and associated partial juvenile skeleton found in continental detrital sediments, were described by Ronan Allain et al. in early 2004. The generic name derives from one of the localities, Tazouda, while the specific descriptor is a latinization of the Arabic term for slender due to the animal’s small size for a sauropod.Tazoudasaurus, a small sauropod at 9 meters long (30 ft), is characterized by rather primitive features such as the prosauropod-like mandible with spatulate and denticle-bearing teeth, lack of an U-shaped mandibular symphysis as other more derived sauropods. Teeth wear in V-shaped marks indicates tooth occlusion, suggesting that vulcanodontids processed food orally when feeding. The neck is flexible with elongate vertebrae that lack true pleurocoels while dorsal and caudal vertebrae series tend to be more rigid. T. naimi bears the most complete fossil skeleton for Early Jurassic sauropod remains found to date due to the scarcity of exposed strata of that age. This sauropod is most closely related to Vulcanodon differing only in caudal vertebrae features while it also possesses characters that place it outside Eusauropoda.

• Vulcanodon (meaning "volcano tooth") was a relatively small, early sauropod dinosaur genus from the Early Jurassic. It was about 6.5 meters (20 ft) long. Vulcanodon ate plants and lived in southern Africa. The type species, V. karibaensis, was formally described by Michael A. Raath of the University of the Witwatersrand, Johannesburg, in 1972. It was originally believed to be a prosauropod because of the knife shaped teeth found near its fossils, which fit in with the idea that prosauropods were omnivorous, but scientists now know that the teeth belonged to an unidentified theropod that scavenged on the Vulcanodon's carcass. The first fossils of Vulcanodon were found with the tooth sandwiched between volcanic flows, giving it its name.

Paul Iacovella/OLMC/yr4/2009

Wellnhoferia is a genus of early prehistoric bird closely related to Archaeopteryx. It lived in what is now Germany, during the Late Jurassic. While Wellnhoferia was similar to Archaeopteryx, it had a shorter tail and its fourth toe was shorter than in Archaeopteryx. Andrzej Elżanowski (2001) of the Institute of Zoology of the University of Wrocław, Poland, determined the differences resulted from a "phylogenetic reduction rather than individual variation.” Wellnhoferia (orange) and seven specimens of Archaeopteryx compared to a human foot in scaleThe type specimen is the Solnhofen Specimen of Archaeopteryx (BSP 1999). Discovered in the 1960s near Eichstätt, Germany and described in 1988 by Wellnhofer (as a specimen of Archaeopteryx) it is currently located at the Bürgermeister-Müller-Museum in Solnhofen. It was originally classified as a Compsognathus by an amateur collector.Although Elżanowski found significant differences between Wellnhoferia and Archaeopteryx, one later study (Mayr et al. (2007)) found Wellnhoferia was a specimen of Archaeopteryx lithographica. Senter and Robins (2003), however, supported Elżanowski's naming of a new genus.

• The Zigongosaurus got its name from where it was found, like most dinosaurs. The first finding was in Shaximiao Formation of Ziging, Sichuan, China. There have only been fragmentary remains found. This dinosaur was very similar to the Omeisaurus which also is in the same dinosaur group. Some are saying that the Zigongosaurus is actually a Mamenchisaurus because neural spines of the vertebrae of both dinosaurs have a unique distinctive weak bifurcation, or splitting. The Omeisaurus simply did not. Due to this information there is a great chance that this dinosaur may have this identity problem. It was estimated at 60feet in length and 25feet in height, and probably moved in herds as a herbivore.

Paul Iacovella/OLMC/yr4/2009

Environment

Paul Iacovella/OLMC/yr4/2009

Palaeoceanography: methane release in the Early Jurassic period.. Dramatic global warming, triggered by release of methane from clathrates, has been postulated to have occurred during the early Toarcian age in the Early Jurassic period. Kemp et al. claim that this methane was released at three points, as recorded by three sharp excursions of delta13C(org) of up to 3 per thousand magnitude. But they discount another explanation for the excursions: namely that some, perhaps all, of the rapid excursions could be a local signature of a euxinic basin caused by recycling of isotopically light carbon from the lower water column. This idea has been proposed previously (see ref. 3, for example) and is supported by the lack evidence for negative delta13C excursions in coeval belemnite rostra. Kemp et al. dismiss this alternative, claiming that each abrupt shift would have required the recycling of about double the amount of organic carbon that is currently present in the modern ocean; however, their measurements are not from an ocean but from a restricted, epicontinental seaway and so would not require whole-ocean mixing to achieve the excursions.