What was dinosaurs habitat

The vast, windswept plains of the Cretaceous period were very similar to those of today, with one major exception: million years ago, grass had yet to evolve, so these ecosystems were instead covered with ferns and other prehistoric plants.

These flatlands were traversed by herds of plant-eating dinosaurs including ceratopsians , hadrosaurs, and ornithopods , interspersed with a healthy assortment of hungry raptors and tyrannosaurs that kept these dimwitted herbivores on their toes.

Wetlands are soggy, low-lying plains that have been flooded with sediments from nearby hills and mountains. Paleontologically speaking, the most important wetlands were the ones that covered much of modern Europe during the early Cretaceous period, yielding numerous specimens of Iguanodon , Polacanthus and the tiny Hypsilophodon.

These dinosaurs fed not on grass which had yet to evolve but more primitive plants known as horsetails. A riparian forest consists of lush trees and vegetation growing alongside a river or marsh; this habitat provides ample food for its denizens but is also prone to periodic flooding. The most famous riparian forest of the Mesozoic Era was in the Morrison Formation of late Jurassic North America—a rich fossil bed that has yielded numerous specimens of sauropods, ornithopods, and theropods, including the giant Diplodocus and the fierce Allosaurus.

Swamp forests are very similar to riparian forests, with one important exception: The swamp forests of the late Cretaceous period were matted with flowers and other late-evolving plants, providing an important source of nutrition for huge herds of duck-billed dinosaurs. In turn, these "cows of the Cretaceous" were preyed on by smarter, more agile theropods, ranging from Troodon to Tyrannosaurus Rex.

Deserts present a harsh ecological challenge to all forms of life, and dinosaurs were no exception. In fact, the entwined fossils of a Protoceratops locked in combat with a Velociraptor were preserved by a sudden, violent sandstorm one unlucky day during the late Cretaceous period.

The world's largest desert—the Sahara—was a lush jungle during the age of the dinosaurs. Lagoons—large bodies of calm, tepid water trapped behind reefs—weren't necessarily more common in the Mesozoic Era than they are today, but they tend to be overrepresented in the fossil record because dead organisms that sink to the bottom of lagoons are easily preserved in silt.

The most famous prehistoric lagoons were located in Europe. For example, Solnhofen in Germany has yielded numerous specimens of Archaeopteryx , Compsognathus , and assorted pterosaurs. During the Mesozoic Era, the North and South Poles weren't nearly as cold as they are today—but they were still plunged in darkness for a significant portion of the year.

During the million years that dinosaurs walked the Earth, the break-up of the supercontinent Pangaea and the resulting major changes of climate produced many different habitats. Continental drift changed the world? Different dinosaurs evolved to live in different environments. Those that had existed on the dry Triassic supercontinent were quite different from those that lived on the scattered landmasses of the Cretaceous. During the Triassic, all the landmasses of the world were joined together, forming the single supercontinent, Pangaea.

Because the continent was so huge, most inland areas were a long way from the ocean and there were extensive deserts. Only around the edges of the continent was there enough moisture for any vegetation. This was the time of the first dinosaurs and they lived everywhere.

Plant and animal life was most common along the banks of rivers near the sea. The river banks were covered with ferns and the shallow water supported reed beds of horsetails. Early carnivorous dinosaurs such as Herrerasaurus hunted in these thickets. The semi-desert supported a scrubby growth of plants that could tolerate a lack of water.

Fossil photos can also be viewed as published plates within many online USGS publications. The best keywords for searches are author names, such as William Cobban, Norm Filter Total Items: Year Published: Divisions of geologic time Bookmark DescriptionThis bookmark presents information that is widely sought by educators and students. View Citation. Geological Survey, , Divisions of geologic time ver. Springer, Kathleen B.

Springer, K. Geological Survey Fact Sheet —, 4 p. Year Published: Why Study Paleoclimate? Why Study Paleoclimate? Year Published: Divisions of Geologic Time—Major Chronostratigraphic and Geochronologic Units Effective communication in the geosciences requires consistent uses of stratigraphic nomenclature, especially divisions of geologic time. Geological Survey Geologic Names Committee. Year Published: A tapestry of time and terrain Vigil, J.

A tapestry of time and terrain; ; I; ; Vigil, J. Year Published: Geologic age: using radioactive decay to determine geologic age At the close of the 18th century, the haze of fantasy and mysticism that tended to obscure the true nature of the Earth was being swept away. Geologic Survey. Year Published: Mud fossils At the close of the 18th century, the haze of fantasy and mysticism that tended to obscure the true nature of the Earth was being swept away.

Year Published: Chicxulub impact event; computer animations and paper models Alpha, T. Year Published: This dynamic earth: the story of plate tectonics In the early s, the emergence of the theory of plate tectonics started a revolution in the earth sciences.

Kious, W. Jacquelyne; Tilling, Robert I. Filter Total Items: 5. Date published: March 21, Date published: August 31, Date published: November 24, Attribution: Region 7: Upper Colorado Basin. Even unpromising chunks of rock will be pounded down to nuggets the size of sugar cubes; the team will check the bits for mammal jaws that are so small they could fit on a postage stamp. It was the prospect of finding ancient mammal bones—not dinosaurs—that drew Rich to Australia.

He was never a dinomaniac, not even as a child. What hooked his imagination, though, were the early mammals that scurried around at the same time as the dinosaurs. One illustration in a book he read as a boy portrayed the animals as snacking triumphantly on dinosaur eggs.

Rich went with the evolutionary winners and studied fossil hedgehogs for his doctorate at Columbia University. He landed in Australia in the early s with no job and no intention of looking for one. His wife, Patricia Vickers-Rich, also a paleontologist, was in the country to follow up on her PhD research on fossil birds. But while thumbing through a newspaper "to get an idea what this country was about" he saw a help wanted ad for a curator at the local museum.

He got the job and works there to this day. Rich and his wife—now a professor at Monash University in Melbourne and chief collaborator on the dinosaur research—stayed here because, he says, "the country was wide open" for studying the early evolution of mammals and birds.

In , Rich met some museum volunteers eager to get their hands dirty at a dinosaur dig, but he initially resisted their pleas. He knew of a site miles west of Flat Rocks that he had dubbed Dinosaur Cove after finding a few unidentifiable bone fragments there years earlier. Excavating there would require tunneling into cliffs—a dangerous proposition—with no guarantee of finding anything. But in he finally gave in, and within weeks the team found several dinosaur bones and a tooth. For ten years Rich and a mostly amateur crew blasted, bored, picked and chiseled into the steep hillside.

They dug two tunnels, each more than 60 feet long, and moved more than tons of rock, much of it by hand. Rich says that "you wouldn't have to work that hard in Montana," which is famous for its dinosaur deposits and where the tectonic movements that hoisted the Rockies exposed bone-harboring rock strata.

In contrast, Rich calls Australia, where dinosaur sediments are mostly buried deep, a "crappy country for dinosaur fossils. By weight, the haul from the decade-long Dinosaur Cove dig was relatively small, about pounds of fossils, and only traces of the mammals Rich covets—an arm bone and a shard of tooth. But the finds supplied clues about polar dinosaurs' metabolism and their strategies for weathering the long winters.

They even provided a rare glimpse of the creatures' brains. Poring over the skeletons made Rich one of the world's experts on polar dinos. At the time dinosaurs arose, around million years ago, the earth's continents were fused into a single supercontinent we now call Pangea. It began breaking up around million years ago, and Australia and Antarctica, which were still stuck together, stayed near the South Pole.

When the fossilized creatures Rich studies were scurrying around, about million years ago, southern Australia sat close to the bottom of the planet, and was just starting to pull away from Antarctica.

Australia's current position reflects that it has been inching northward "at the rate your fingernails grow," Rich says.

During the animals' heyday in the early Cretaceous period, the sun didn't rise in southern Australia for one and a half to four and a half months every year. At the North and South poles, the gloom lasted for six months. Plant growth in these areas would have periodically slowed or stopped, potentially creating a food crisis for any dinosaurs that lived there.

In more than 20 years of digging, Rich and his colleagues have found the remains of at least 15 species. For example, the knee-high hypsi Leaellynasaura amicagraphica named for Rich's daughter, Leaellyn once dodged predators at what is now Dinosaur Cove.

Rich's son, Tim, got his name attached to another Dinosaur Cove denizen, the six-foot-tall Timimus hermani , which probably looked and ran like an ostrich. Dinosaurs also thrived farther south. Antarctica hasn't moved much in the past million years, stalling over the South Pole.

Today, well-insulated animals and stubbly plants can survive the continent's brutal cold, at least close to the coast. But fossilized leaves and other plant remains suggest that during the dinosaurs' day Antarctica had a temperate climate.

Judd Case of Eastern Washington University in Cheney says that Antarctic dinosaurs from the late Cretaceous period around 70 million years ago resembled those that lived in other parts of the world some 60 million years earlier. Case says this suggests that some kinds of dinosaurs hung on in Antarctica long after they had died out elsewhere.