Tarbosaurus

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Tarbosaurus at the Naturkundemuseum Münster in Münster, Germany.

Photo credit: Commons:User:Thomas Ihle

Daspletosaurus

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Daspletosaurus (meaning 'frightful lizard') was a genus of tyrannosauridtheropod dinosaur that lived in western North America between 80 and 73 million years ago, during the Late Cretaceous Period. Fossils of the only named species (D. torosus) were found in Alberta, although other possible species from Alberta, Montana and New Mexico await description. Including these undescribed species, Daspletosaurus is the most species-rich genus of tyrannosaur.

Daspletosaurus is closely related to the much larger and more recent Tyrannosaurus. Like most known tyrannosaurids, it was a multi-ton bipedal predator equipped with dozens of large, sharp teeth. Daspletosaurus had the small forelimbs typical of tyrannosaurids, although they were proportionately longer than in other genera. It was probably similar in weight to a modern white rhinoceros or a small elephant.

As an apex predator, Daspletosaurus was at the top of the food chain, probably preying on large dinosaurs like the ceratopsid Centrosaurus and the hadrosaur Hypacrosaurus. In some areas, Daspletosaurus coexisted with another tyrannosaurid, Gorgosaurus, though there is some evidence of niche differentiation between the two. While Daspletosaurus fossils are rarer than other tyrannosaurids, the available specimens allow some analysis of the biology of these animals, including social behavior, diet and life history.

Styracosaurus

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Styracosaurus (meaning 'spiked lizard') was a genus of herbivorousceratopsian dinosaur from the Cretaceous Period (Campanian stage), about 74 to 72 million years ago. It had four to six long horns extending from its neck frill, a smaller horn on each of its cheeks and a single horn protruding from its nose, which was around 60 centimeters (2 ft) long and 15 centimeters (6 in) wide. The function or functions of the horns and frills have been the subject of debate for many years. Styracosaurus was a large dinosaur, reaching lengths of 5.5 meters (18 ft) and weighing nearly 3 tons. It stood about 1.8 meters (6 ft) tall. Styracosaurus possessed four short legs and a bulky body. Its tail was rather short. It also had a beak and flat cheek teeth, indicating that its diet was herbivorous. Like other ceratopsians, this dinosaur may have been a herd animal, traveling in large groups, as suggested by bonebeds. Named by Lawrence Lambe in 1913, Styracosaurus is a member of the Centrosaurinae. Three species, S. albertensis, S. ovatus, and S. parksi are currently assigned to Styracosaurus, though the last species may be synonymous with S. albertensis. Other species assigned to the genus have since been reassigned elsewhere.

Thescelosaurus

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Thescelosaurus (meaning 'wondrous lizard') was a genus of small ornithopoddinosaur that appeared at the very end of the Late Cretaceous period in North America and was a member of the last dinosaurian fauna before the Cretaceous-Tertiary extinction event around 65.5 million years ago. The preservation and completeness of many of its specimens indicate that it may have preferred to live near stream channels.

This bipedal ornithopod is known from several partial skeletons and skulls that indicate it grew to between 2.5 and 4.0 meters (8.2 to 13.1 feet) in length on average. It had sturdy hind limbs, small wide hands, a head with an elongate pointed snout, and possibly small armor scutes along the midline of the back. This genus of dinosaur is regarded as a specialized hypsilophodont and a herbivore. Several species have been suggested for this genus, but only one, T. neglectus, is currently recognized; the others have been given their own genera, or are believed to be the same as T. neglectus.

The genus attracted media attention in 2000, when a specimen unearthed in 1993 in South Dakota was interpreted as including a fossilized heart. There was much discussion over whether the remains were actually of a heart. Many scientists now doubt the identification of the object and the implications of such an identification.

Archaeopteryx

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Archaeopteryx (meaning 'ancient feather') is the earliest and most primitive known avian to date. It lived in the late Jurassic Period around 155-150 million years ago in what is now southern Germany. At the time Archaeopteryx lived, Europe was an archipelago of islands in a shallow warm tropical sea, much closer to the equator than it is now. Archaeopteryx lived during the time of the dinosaurs, yet was set apart from them because of the inclusion of both avian and theropod dinosaur features. Similar in size and shape to a European Magpie, it bore broad, rounded wings and a long tail. Archaeopteryx could grow to about half a metre, or 1.6 feet in length. Its feathers resembled those of modern birds but Archaeopteryx was rather different from any bird known today, in that it had jaws lined with sharp teeth, three 'fingers' ending in curved claws and a long bony tail. These features, which are consistent with theropod dinosaurs, have made the Archaeopteryx a hot topic in the debate on evolution. Indeed, in 1862 the description of the first intact specimen of Archaeopteryx, just two years after Charles Darwin published The Origin of Species, set off a firestorm of debate about evolution and the role of transitional fossils that endures to this day. The eleven fossils currently classified as Archaeopteryx are the oldest evidence of feathers on the planet and the only ones dated from Jurassic times. Furthermore, their advanced nature and placement suggest their origins must have been even earlier. All remains have been regarded by most as a single species, though this has been debated

Psittacosaurus

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Psittacosaurus (meaning 'parrot lizard') was a genus of psittacosauridceratopsian dinosaur from the Early Cretaceous Period of what is now Asia, about 130 to 100 million years ago. It is notable for being the most species-rich dinosaur genus; At least eight extinct species are recognized from fossils found in different regions of China and Mongolia, with possible additional species from Thailand and Russia.

All species of Psittacosaurus were gazelle-sized bipedal herbivores characterized by a high, powerful beak on the upper jaw. At least one species had long, quill-like structures on its tail and lower back, possibly serving a display function. Psittacosaurs were extremely early ceratopsians and, while they developed many novel adaptations of their own, they also shared many anatomical features with later ceratopsians, such as Protoceratops and the elephant-sized Triceratops.

Psittacosaurus is not as familiar to the general public as its distant relative Triceratops but it is one of the most completely known dinosaur genera. Fossils of over 150 individuals have been collected so far, including many near-complete skeletons. Most different age classes are represented, from nestling through to adult, which has allowed several detailed studies of Psittacosaurus growth rates and reproductive biology. The abundance of this dinosaur in the fossil record has led to its use as an index fossil for Early Cretaceous sediments of

Albertosaurus

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Albertosaurus (meaning 'Alberta lizard') was a genus of tyrannosauridtheropod dinosaur that lived in western North America during the Late Cretaceous Period, more than 70 million years ago. The type species, A. sarcophagus, was restricted in range to the modern-day Canadian province of Alberta, after which the genus is named. Scientists disagree on the number of species represented in the genus, recognizing either one or two species. As a tyrannosaurid, Albertosaurus was a bipedal predator with a massive head, jaws lined with dozens of large teeth and tiny, two-fingered 'hands' and it may have been at the top of the food chain in its local ecosystem. Although relatively large for a theropod, Albertosaurus was much smaller than its more famous relative Tyrannosaurus, probably weighing only as much as a modern black rhinoceros. Fossils of more than twenty individuals have been recovered, providing scientists with a more detailed knowledge of Albertosaurus anatomy than is available for other tyrannosaurids. The discovery of ten individuals at one site provides evidence of pack behavior and allows studies of developmental biology which are impossible with lesser-known animals

Compsognathus

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Compsognathus (meaning 'elegant jaw') was a small, bipedal, carnivoroustheropod dinosaur. The animal was the size of a chicken and lived around 150 million years ago, during the early Tithonian stage of the late JurassicPeriod, in what is now Europe. Paleontologists have found two well-preserved fossils, one in Germany in the 1850s and the second in France more than a century later. Compsognathus is one of the few dinosaurs for which the diet is known with certainty: the remains of small, agile lizards are preserved in the bellies of both specimens. Teeth discovered in Portugal may be further fossil remains of the genus. Although not recognized as such at the time of its discovery, Compsognathus is the first dinosaur known from a reasonably complete skeleton. Today, C. longipes is the only recognized species, although the larger specimen discovered in France in the 1970s was once thought to belong to a separate species, C. corallestris. Until the 1980s and 1990s, Compsognathus was the smallest known dinosaur and the closest supposed relative of the early bird Archaeopteryx. Thus, the genus is one of the few dinosaur genera to be well known outside of paleontological circles

Velociraptor

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Velociraptor (meaning 'swift thief') was a genus of dromaeosaurid theropoddinosaur that existed approximately 83 to 70 million years ago during the later part of the Cretaceous Period. There is only one currently recognized species, V. mongoliensis, although others have been assigned in the past. Fossils of this species have been found in central Asia, from both Inner and Outer Mongolia.

Smaller than other dromaeosaurids like Deinonychus and Achillobator, the turkey-sized Velociraptor nevertheless shared many of the same anatomical features. It was a bipedal carnivore with a long, stiffened tail and had an enlarged, sickle-shaped claw on each hindfoot, which is thought to have been used to kill its prey. Velociraptor can be distinguished from other dromaeosaurids by its long and low skull, with an upturned snout.

Due in large part to its prominent role in Michael Crichton's novel Jurassic Park and the subsequent motion picture series, Velociraptor (commonly shortened to 'raptor') is one of the dinosaur genera most familiar to the general public. It is also well-known to paleontologists, with over a dozen recovered fossil skeletons — the most of any dromaeosaurid. One particularly famous specimen shows a Velociraptor locked in combat with a Protoceratops

Stegosaurus

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Stegosaurus (meaning 'roof-lizard') is a genus of stegosaurid armoureddinosaur from the Late Jurassic period (Kimmeridgian to Early Tithonian) in what is now western North America. However, in 2006 a specimen of Stegosaurus was announced from Portugal, suggesting that they were present in Europe as well. Due to its distinctive tail spikes and plates, Stegosaurus is one of the most recognisable dinosaurs, along with Tyrannosaurus, Triceratops and Apatosaurus. 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 155 to 145 million years ago, in an environment and time dominated by the giant sauropods Diplodocus, Camarasaurus and Apatosaurus. A large, heavily-built and 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 have been the subject of much speculation. The spikes were most likely used for defence, 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

Diplodocus

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Diplodocus whose fossilised skeleton was first discovered in 1878. The generic name refers to its double-beamed (meaning 'double bar') is a genus of diplodocid sauropod dinosaurchevron bones (Greek diplos/διπλος meaning 'double' and dokos/δοκος meaning 'wooden beam' or 'bar') located in the underside of the tail. They were initially believed to be unique to Diplodocus; however, they have since then been discovered in other diplodocids. It lived in what is now western North America at the end of the Jurassic Period. Diplodocus was one of the more common dinosaurs found in the Upper Morrison Formation, about 150 to 147 million years ago, in what is now termed the Kimmeridgian and Tithonian stages. This was an environment and time dominated by gigantic sauropod dinosaurs such as Camarasaurus, Barosaurus, Apatosaurus and Brachiosaurus. Diplodocus is among the most easily identifiable dinosaurs, with its classic dinosaur shape, long neck and tail and four sturdy legs. For many years, it was the longest dinosaur known. Its great size may have been a deterrent to the predators Allosaurus and Ceratosaurus: their remains have been found in the same strata, which suggests they coexisted with Diplodocus.

Triceratops

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Triceratops (meaning 'three-horned face') was a herbivorous genus of ceratopsid dinosaur that lived during the late Maastrichtian stage of the Late Cretaceous Period, around 68 to 65 million years ago (mya) in what is now North America. It was one of the last dinosaurs to appear before the great Cretaceous–Tertiary extinction event. Bearing a large bony frill and three horns on its large four-legged body and conjuring similarities with the modern rhinoceros, Triceratops is one of the most recognizable of all dinosaurs. Though it shared the landscape with, and was preyed upon by the fearsome Tyrannosaurus, it is unclear whether the two battled the way they are commonly depicted in movies and children's dinosaur books.

Although no complete skeleton has been found, Triceratops is well-known from numerous partial specimens collected since the introduction of the genus in 1887. The function of their frills and three distinctive facial horns has long inspired debate. Although traditionally viewed as defensive weapons against predators, the latest theories explain how these features were probably primarily used in display for courtship and dominance, much like the antlers and horns of modern reindeer, mountain goats or rhinoceros beetles.

Triceratops is the best-known of the ceratopsids, though the genus' exact placement within the group has been a point of contention amongst paleontologists. Two species, T. horridus and T. prorsus, are considered valid, although many other species have been named.

Iguanodon

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Iguanodon and the ornithopods' culmination in the (meaning "Iguana tooth") is a genus of ornithopod dinosaur that lived roughly halfway between the first of the swift bipedal hypsilophodontidsduck-billed dinosaurs. Most Iguanodon species lived between 140 to 120 million years ago, in the Valanginian to Barremian ages of the Early Cretaceous Period of Europe, although possible remains are known from North America, Asia, and Africa. Iguanodon's most distinctive features were its large thumb spikes, which were possibly used for defence against predators.

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.

Scientific understanding of Iguanodon has evolved over time as new information has been obtained from the fossils. The numerous specimens of this genus, including nearly complete skeletons from two well-known bonebeds, have allowed researchers to make informed hypotheses regarding many aspects of the living animal, including feeding, movement, and social behaviour. As one of the first scientifically well-known dinosaurs, Iguanodon has occupied a small but notable place in the public's perception of dinosaurs, its artistic representation changing significantly in response to new interpretations of its remains

Tyrannosaurus

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Tyrannosaurus (meaning 'tyrant lizard') is a genus of tyrannosauridtheropod dinosaur. The species Tyrannosaurus rex, commonly abbreviated to T. rex, is one of the dinosaurs most often featured in popular culture around the world. It hails from what is now western North America.

Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to the large and powerful hindlimbs, Tyrannosaurus forelimbs were small and retained only two digits. Although other theropods rivaled or exceeded T. rex in size, it was the largest known tyrannosaurid and one of the largest known land predators, measuring over 13 metres (43 feet) in length and up to 7.5 tons in weight.

Fossils of some T. rex have been found in North American rock formations dating to the very end of the Cretaceous Period (late Maastrichtian stage, 65 million years ago); it was among the last dinosaurs to exist prior to the Cretaceous-Tertiary extinction event. More than 30 specimens of T. rex have now been identified, some nearly complete, which has allowed significant research into many aspects of its biology, including its life history and biomechanics. The feeding habits and potential speed of T. rex remain controversial

Excalibosaurus

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Excalibosaurus Fossil range: Early Jurassic
Excalibosaurus costini
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Sauropsida Order: Ichthyosauria Suborder: Eurhinosauria Family: Leptonectidae Genus: Excalibosaurus McGowan, 1986
Binomial name
Excalibosaurus costini McGowan, 1986

Excalibosaurus (meaning "Excalibur's lizard") is a monotypic genus of marine prehistoric fish-like reptiles (ichthyosaurs) that lived during the Sinemurian stage (approximately 196.5 ± 2 Ma to 189.6 ± 1.5 Ma (million years ago)) of the Early Jurassic period in what is now England. It is characterized by the extreme elongation of the rostrum, with the lower jaw about three fourth of the length of the upper jaw, giving the animal a swordfish-like look. The only known species is Excalibosaurus costini.

Description

This relatively rare animal is known from two skeletons. The holotype, discovered in 1984 near a beach on the Somerset coast, consists of the skull, forefin, part of the pectoral girdle and some vertebrae and ribs. It has been described in 1986 by McGowan.^[1] The fossil is hosted in the City of Bristol Museum and Art Gallery. The second specimen is an almost complete skeleton collected in the same area in 1996, and was purchased by the Royal Ontario Museum. It was described again by McGowan in 2003.^[2]

Excalibosaurus is related to two other genera of ichthyosaurs, Leptonectes from the Rhaetian (Late Triassic) to the Sinemurian (Early Jurassic) of England and Eurhinosaurus from the Toarcian (Early Jurassic) of Germany. The three genera are grouped in the family Leptonectidae^[3] and the suborder Eurhinosauria.^[4] It was once thought that Excalibosaurus was a junior synonym of Eurhinosaurus,^[5] but the description of the 1996 specimen show many morphological differences such as the shape of the forefin (much shorter and broader in Excalibosaurus), the slender shape of the body, that clearly differenciate the two genera.^[2] The estimate body length of the 1996 specimen is 7 m with a 1.54 m long skull. The holotype specimen was much smaller, with a skull length of 0.785 m and an estimated body length of 4 m, indicating that it was a juvenile.