What were the smallest and largest dinosaurs known in the Cretaceous period?

It is difficult to determine the smallest dinosaurs known from the Cretaceous period. In general, the smallest herbivorous and carnivorous dinosaurs could be as small as a chicken. Most of the carnivorous ones ate insects as their main supply of food; and, of course, the smallest herbivores ate plants.

One contender for the smallest is the Microraptor (meaning little plunderer), a bird-like, crow-sized dinosaur from China. This coelurosaurid theropod was about 16 inches (40 centimeters) long. It may have lived in trees, as its feet were perfect for climbing. Another possibility is the Wannanosaurus (named after the Chinese province in which the incomplete skeleton was found). This tiny homalocephalid dinosaur, measuring about 2 feet (60 centimeters) long, was a very primitive pachycephalosaur (related to Pachycephalosaurus and Stegoceras).

Scientists probably have yet to uncover the largest dinosaurs of the Cretaceous period. One of the largest and most relatively complete skeletons comes from the Brachiosaurus of Tanzania, Africa, which measured up to 75 feet (23 meters) in length. But this sauropod didnt make it through the Cretaceous. It evolved around the Late Jurassic period and died out by the Early Cretaceous.

One of the largest carnivorous dinosaurs yet discovered is the Gigantosaurus, which lived in what is now South America and was well over 40 feet (13 meters) long (Big Stock Photo).

More recent fossil discoveries may lead to even larger sauropods. One includes a massive herbivorous dinosaur Argentinosaurus huinculensis, a South American sauropod of the Titanosauridae family, measuring between 130 and 140 feet (40 and 42 meters) long. Another contender is the second-largest sauropod so far found, the Paralititan (meaning tidal Titan), a titanosaurid sauropod found in Egypt that lived about 100 million years ago.

Currently, the largest carnivorous dinosaur from the Cretaceous period seems to be a toss-up between the perennial favorite and several newcomers. The favorite is the theropod Tyrannosaurus, found in North America and Asia and measured over 40 feet (12 meters) in length. The other challengers include: The longest meat-eating dinosaur yet discovered, the 44- to 46-foot- (13.5- to 14.3-meter-) long Giganotosaurus of South America; the Spinosaurus a bipedal carnivore that measured about 52 to 59 feet long (16 to 18 meters) from Africa; and the 26- to 44-feet- (8- to 14-meter-) long Carcharodontosaurus saharicus of North Africa. All of these huge, meat-eating theropods are thought to have been around the same size and maybe even heavier than the Tyrannosaurus.

What was the top predator among the Cretaceous dinosaurs?

This question is difficult to answer. The carnivorous dinosaurs were all vicious as they attacked their prey. Some, like Tyrannosaurus rex, used their size to catch their meals; while others were pack hunters, such as the Velociraptor, which trapped prey by working together as a unit. Or was it better to be fast or even agile,

such as the Utahraptor or Megaraptor? In other words, the top predator is a matter of opinion.

What is the oldest-known horned dinosaur?

The oldest-known horned dinosaur is the Zuniceratops christopheri. The fossil remains of this animal were recently discovered by Chris Wolfe, an eight-year-old third-grader from Phoenix, Arizona. This dinosaur lived some 90 to 92 million years ago, had three horns, and might have been 10 to 12 feet (3 to 4 meters) long, with a weight of approximately 200 to 250 pounds (100 to 150 kilograms). The remains were discovered in western New Mexico and include jaw parts, the brain case, teeth, a horn, and the brow.

Where did the last dinosaurs live?

The last dinosaurs apparently lived in the western regions of North America. Their remains have been found through Late Cretaceous period rocks, while in other regions of the world they disappeared well before the end of this period. Two of the last known species of dinosaurs to arise in the Late Cretaceous period were the Triceratops, a herbivore, and Tyrannosaurus rex, a carnivore.

Did any dinosaur species survive the extinction at the end of the Cretaceous period?

The general consensus among scientists is that no dinosaur species survived the mass extinction at the end of the Cretaceous period. There are a few paleontologists who dont believe that the dinosaurs died off at the end of the Cretaceous period, but actually lived on, dying out gradually into the Cenozoic era. This theory will continue to be highly debated until dinosaur fossils are proven to exist past the Cretaceous period in rocks. Some scientists claim they have found such evidence, but their findings are still controversial.

In addition, if the definition of dinosaurs includes the birds, then, yes, this family of dinosaurs did survive the extinction. After the Cretaceous period, birds greatly diversified into numerous species, and as we well know, these are species are living everywhere on the planet today.

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