What are the smallest dinosaur fossils found to date?
There is some disagreement as to the smallest dinosaur fossil yet found. To date, the best contender for the smallest is the Microraptor (little plunderer), a bird-like
(crow-sized) dinosaur from China, a coelurosaurid theropod about 16 inches (40 centimeters) long. Another vote for the smallest adult dinosaur fossil found to date is the Compsognathus (pretty jaw). This animal was slightly larger than a turkey, with a total length of approximately 3 feet (1 meter), and weighed approximately 6.5 pounds (2.9 kilograms). This small carnivore, nicknamed Compy, lived during the Jurassic period and was a fast-running, agile predator that probably subsisted on insects, frogs, and small lizards.
There was once another claim for smallest dinosaur fossil: the Mussaurus, or mouse lizard, was found in 1979 in South America. Once thought to be the smallest dinosaur, it is now known that the Mussaurus fossils were actually hatchlings of Coloradisaurus, which, when fully grown, would be larger than a Compsognathus. Their eggs were only 1 inch (2.54 centimeters) long; the fossil hatchlings were only 7.8 to 16 inches (20 to 40 centimeters) long.
Where have dwarf dinosaur fossils been found?
Dwarf dinosaur fossils have been found in Hateg, Romania. During the Late Cretaceous period, much of the land area of eastern Europe was inundated by the waters of the Tethys Sea. Thus, the land existed in the form of islands.
Dinosaurs, along with other animals and plants, were isolated on these islands, cutting the flora and fauna off from other larger landmasses. Over time, the dinosaurs on these islands became smaller in response to the limited ecological environment. For example, the Telmatosaurus, a primitive hadrosaur found in Hateg, was about 15 feet (5 meters) long, and weighed approximately 1,10 pounds, or just over a half ton (450 kilograms). This is about one-third the length and one- tenth the weight of other Telmatosaurus fossils found in other parts of the world. The larger dinosaurs were able to take advantage of greater territories and habitats, growing much more than their smaller, island-bound cousins.
Which dinosaur had the longest neck of any animal known?
Although the true longest neck is highly debated, it is thought that the Barosaurus, or heavy lizard, had the longest neck of any known dinosaur. The reason for the debate is that fossils of the Barosaurus are some of the rarest known. Because there are not many other specimens to back up the longest-neck claim, many scientists do not believe this animal is the winner. Even though there is still debate, the Barosaurus, which was related to the Diplodocus, did have an enormously long neck that was thought to be longer than the Brachiosaurus. Fossil remains of the Barosaurus have been found in the western United States and in Africa. The only mounted skeleton in the world of Barosaurus is found in New York City at the American Museum of Natural History; it is depicted rearing up on its hind legs, as if confronting a predator.
Most of the longest necks belonged to the sauropod (herbivore) dinosaurs, creatures that probably needed the longer necks to reach food in high tree branches.
Other major contenders include the Brachiosaurus, a sauropod that reached a height of 40 feet (12.2 meters), with much of that height a combination of its long neck and front legs. Still another is the Mamenchisaurus, a sauropod with a 33- foot- (10-meter-) long neck.
To date, the longest neck in relation to its body belongs to the Erketu ellisoni, a sauropod with a neck more than 24 feet (8 meters) long. It lived in what is now Mongolias Gobi Desert about 120 to 100 million years ago.
What was possibly the longest predatory dinosaur?
Scientists believe that a predatory dinosaur called Spinosaurus aegypticus may have been 52 to 59 feet (16 to 18 meters) long, making it one of the largest predators, if not the largest. The animals long spine evolved during the Early Cretaceous period. (In fact, one vertebra of a Spinosaurus is taller than the average human.) The tall spines formed a skin-encased, sail-like structure; some scientists suggest that the long spine was needed to hold the sails. No one knows the function of the structure, but there are some theories. One states that, because the animals lived in the tropics close to sea level, the sails may have been used to cool off the animals. Another idea is that the sails were used for attracting potential mates, or for scaring off potential rivals or other dinosaur predators.