Dinosaurs with Pictures Trivia Quiz

Answer: Mixosaurus

Mixosaurus fossils are now considered to be a transitional form between the earlier eel-shaped ichthyosaurs and the later dolphin-shaped ones. They were decreed to be a separate genus in 1887 by George H. Baur, based on the structure of their forefins. They had five toes, not the three of later ichthyosaurs, but shared with them a larger number of bones in the limbs than is common for reptiles.

Mixosaurinae are fairly small (75-100 cm long, 2-6 kg in mass), with an elongated snout and sharp of teeth, excellent for catching the fish which seem to have been the basis of their diet. They are currently grouped into three species - a number which has varied over the years as some species have been reallocated to another genus. Specimens of M. cornalianus, including some complete specimens, have been found in Italy and Switzerland. Unfortunately, compaction during fossilization makes it hard to study them systematically.

Answer: North America

This genus of herbivores lived in North America during the late Jurassic period, something around 150 million years ago. The first one identified, A. ajax, was classified by Othniel Charles Marsh in 1877, using specimens dug up by Arthur Lakes in Morrison CO. Most Apatosaurus fossils have been found in the Morrison Formation, a rock sequence formation located in the US states of Colorado, New Mexico, Oklahoma, Utah which is a rich source of dinosaur bones, and was the site of the famous Bone Wars, a competition between Marsh and fellow paleontologist Edward Drinker Cope to establish who was the Dinosaur Supremo (my term, not theirs).

The average length of an Apatosaurus was about 22 m, and its mass would have been between 16 and 22 tonnes; some, however, were significantly larger than that. Although its forelimbs were shorter than its hindlimbs, it is thought to have been quadrupedal (locomoting on all four limbs). The genus name, which means 'deceptive reptile', was given because the specimen's chevron (a structure on the vertebrae in the tail) looked more like that of a mosasaur (another group of marine reptiles) than a dinosaur.

Answer: Allosaurus

The Allosaurus name comes from the fact that, at the time of its discovery, it was the only dinosaur with concave vertebrae. Identified by Charles Othniel Marsh in 1877, it became one of the first well-known theropods, dinosaurs with hollow bones and three clawed toes on each limb. It was probably an apex predator in the Morrison formation from which most specimens originate, although some have been found in Portugal.

Their forelimbs are distinctly shortened, showing that they were bipedal, running on two legs as they chased their quarry. Juveniles had relatively longer and thinner limbs than adults, leading scientists to hypothesize that youngsters chased smaller prey, while adults were more likely ambush predators. It has also been speculated that they may have hunted in packs, to facilitate the capture of larger prey.

Answer: Brachiosaurus

Brachiosaurus was discovered in Colorado and described by Elmer S. Riggs. The name means 'arm lizard', a reference to the fact that its forelimbs are longer than the rear, which is unusual for dinosaurs found in that region. The specimen he first identified was allocated a species name of altithorax (deep chest) because it had (you guessed it) an unusually deep and wide chest.

With a length of around 20 metres and a weight between 30 and 45 tonnes, Brachiosaurs were long thought to be semiaquatic, living in water to help support their weight. However, since the middle of the 20th century paleontologists have come to agree that they were terrestrial, although they may also have entered the water at times. They were herbivores, probably browsing from tree foliage - their long necks would have let them reach leaves up to 10 metres above the ground.

All current members of the genus lived in the Morrison Formation of North America. The closely related Giraffatitan, found in Tanzania, has been moved to its own genus.

Gallimimus was found in Mongolia, Argentinosaurus was discovered, as the name implies, in Argentina and Nigersaurus in the Republic of Niger.

Answer: True

The classification of this genus is actually somewhat problematic, with paleontologists arguing whether the type specimen was actually a new genus, or an immature specimen of another genus. In any case, Othniel Charles Marsh identified the specimen found by William Harlow Reed in Wyoming as Camptonotus dispar. The genus name meant flexible or bent back; when he discovered that the genus name had already been assigned to a cricket, he changed the dinosaur's name to Camptosaurus. The reference is to the flexibility of the vertebrae at the lower end of the spinal column.

Because so many fragments have been considered to belong to this genus, then moved elsewhere for various reasons, it is hard to find consistent descriptions of its appearance and behavior. Estimates of length vary from 5 to 8 metres, and weight from 500 to 850 kg. Much smaller than some of the others in the quiz, in any case. The original author of this quiz had a source to say that they were quadrupedal, but the reconstructions I can find all indicate that their forelimbs were too short for that to be viable. One thing that is clear is that they were herbivorous - the teeth of older specimens are extremely worn, showing a probable diet of tough leaves.

Answer: many thorns

The image used here is probably not in line with current understanding of the appearance of Polacanthus, but it does show the spikes that earned its name. Currently, only a single species is still classified in the genus. P. foxii was discovered on the Isle of Wight by William Fox in 1865. Since the specimen was not complete, a lot of time has since been spent trying to determine exactly how the spikes along back were arranged (did they extend as far as the tail?), and whether the rows of osteoderms (bony structures that form scales) were in fact fused to make flat plates, or arranged in rows to provide a series of projections.

The current description of the genus states that its length was 4-5 metres (with a height of around 1.5 metres when standing with all four legs on the ground) and its weight was between 250 kg and 2 tonnes - that's a pretty big range! The problem, of course, is that the original type specimen was fragmentary, as are most of the subsequent specimens being analysed.

Answer: Stegoceras

The Stego- part of the name indicates a roof, while -ceras comes from the Greek -keras, for horn. You might recognise the same root involved in keratin, the protein which is key to the formation of nails, claws, horns, feathers and hair. The picture used here is not terribly accurate, but it does show the high-domed bony structure on the head which is the source of the name. It was originally known only from the dome of its skull, but complete skulls have since been found. Even just a skull can provide the ardent paleontologist with a lot of information.

Stegoceras was a small (roughly the size of a goat, but almost 2 metres long with tail) bipedal dinosaur, characterized by a short snout and a really thick dome on top of the skull. The skull also featured lots of small bony outgrowths, some in rows, including some that formed small horns on the back of the skull. It had a lot of small teeth, of a type that suggest it was probably herbivorous.

Answer: Triceratops

Here's a favorite from everyone's first book of dinosaurs. The three horns referred to in its name were two large ones located above its head (located like bovine horns), and a smaller one on the nose, resembling that of a rhinoceros. The large bony frill has been compared in function to a deer's antlers. One of the latest dinosaurs, it is often given as an example of convergent evolution - different species developing similar structures in response to similar environmental pressures.

Triceratops was a gentle giant, a herbivore with a length of up to 9 metres and a weight of up to 9 tonnes. Given the weight of their large heads, they probably grazed on grass. Most specimens have been found as individuals, leading to speculation that they were not herd animals - the only multiple-specimen site involved three juveniles, which may just have meant they were not yet ready to head off on their own.

Answer: Ankylosaurus

These are the largest of the armoured dinosaurs, up to 8 metres long with a mass of 8 tonnes. Its wide muzzle suggests that it grazed on a wide range of foliage, both grasses and leaves. The armour offered a good defense against predators, since it was not a very rapid mover. The spiked tail is thought to have been used in intraspecific combat - fights with other ankylosaurs. There is only one definite member of the genus, A. magniventrix (so named for a large belly). This particular armoured dinosaur also had a lot of its bones fused (providing extra strength), which is the source of its name - ankylosis is the medical term for fusion of bones or stiffness caused by adhesion between the bones in a joint.

The spikes shown in the picture, which is a replica in the Royal Alberta Museum of the model displayed in the 1964 World's Fair are not now considered accurate. It is also thought that the tail was probably carried off the ground, and the posture was more upright, with the legs held in a straighter position.

Velociraptor means 'quick plunderer', Diplodocus means 'double beam lizard', and Iguanodon means 'iguana tooth'.

Answer: Rex

This is the one of the largest carnivores that walked the earth 65 million years ago. This 12-metre long, 6-metre high king of the meat-eaters weighed up to 8 tonnes. Debate rages over whether they were the apex predator of their environment, or a scavenger; it was probably both, but the public imagination definitely pictures T. rex engaged in mortal combat with others - including the Triceratops that lived at the same time. Evidence in fossils of both species indicates that they engaged in battles, but it is not really clear that they fought each other. Still, it makes a good movie scene.

The most complete specimen of T. rex, named Sue, was discovered in 1990, and reconstructed at the Field Museum of Natural History in Chicago. Her dimensions were used in the generic description above. She is estimated to have died at the age of 28, a long life for a Tyrannosaur.