The Cretaceous
Cretaceous
The Cretaceous, derived from the Latin "creta" (chalk), usually abbreviated K for its German translation Kreide (chalk), is a geologic period and system from 145 ± 4 to 66 million years (Ma) ago. In the geologic timescale, the Cretaceous follows the Jurassic Period and is followed by the Paleogene Period of the Cenozoic Era.
What was the Cretaceous period known for?
Cretaceous Period. The lengthy Cretaceous Period constitutes a major portion of the interval between ancient life-forms and those that dominate Earth today. Dinosaurs were the dominant group of land animals, especially “duck-billed” dinosaurs (hadrosaurs), such as Shantungosaurus, and horned forms, such as Triceratops.
What happened to the dinosaurs in the Cretaceous period?
Dinosaurs, pterosaurs, mosasaurs, and ammonoids, to name a few, were among the groups lost at this time. The Cretaceous extinction event is marked by the famous K-T boundary and asteroid impact on what is now the Yucatan peninsula.
What was the most important insect to evolve in the Cretaceous?
Aphids, grasshoppers, and gall wasps appear in the Cretaceous, as well as termites and ants in the later part of this period. Another important insect to evolve was the eusocial bee, which was integral to the ecology and evolution of flowering plants.
How did the Cretaceous affect the earth's surface?
By the beginning of the Cretaceous, the supercontinent Pangea was already rifting apart, and by the mid-Cretaceous, it had split into several smaller continents. This created large-scale geographic isolation, causing a divergence in evolution of all land-based life for the two new land masses.
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How did the Cretaceous Period affect life on Earth?
During this period, oceans formed as land shifted and broke out of one big supercontinent into smaller ones. Continents were on the move in the Cretaceous, busy remodeling the shape and tone of life on Earth.
What is interesting in Cretaceous Period?
The Cretaceous Period started around 145.5 million years ago and ended around 65.5 million years ago. During this period, land on Earth was breaking up into separate continents the way it is today. Flowering plants appeared for the first time, and dinosaurs lived all over the Earth.
What are 3 facts about Cretaceous Period?
The Cretaceous Period was the longest period of the Mesozoic Era. The Cretaceous Period lasted roughly 79 million years. The Cretaceous Period occurred between 145 and 66 million years ago. The Cretaceous Period had two epochs, the Early Cretaceous and Late Cretaceous.
What was the best period for dinosaurs?
The Jurassic Period was a golden time for dinosaurs, which flourished for 180 million years.
What is unique about the Jurassic period?
The Jurassic period (199.6 million to 145.5 million years ago) was characterized by a warm, wet climate that gave rise to lush vegetation and abundant life. Many new dinosaurs emerged—in great numbers. Among them were stegosaurs, brachiosaurs, allosaurs, and many others. Artwork by Publiphoto/Photo Researchers Inc.
Why was the Cretaceous period so warm?
Earth was warmer during the Cretaceous era because the atmosphere contained 3-6 times more carbon dioxide than the current era. Carbon dioxide formed from the decay of large amounts of dead plants.
What was the dinosaur's role in the Pangaea period?
At the start of the period, dinosaurs ruled the loosening remnants of the supercontinent Pangaea as rodents scurried at their feet through forests of ferns, cycads, and conifers. At the end of the period, about 80 million years later, oceans filled yawning gaps between isolated continents shaped much as they are today.
What is the name of the dinosaur that went extinct?
Unauthorized use is prohibited. 1 / 10. 1 / 10. <p><i>Tyrannosaurus rex</i> arose during the Cretaceous period about 85 million years ago, and thrived as a top land predator until the dinosaurs went extinct 20 million years later. This skeleton, on display in Chicago's Field Museum, is a cast of perhaps the world's most famous fossil: "Sue," ...
How did oceans form during the Cretaceous?
During this period, oceans formed as land shifted and broke out of one big supercontinent into smaller ones. Continents were on the move in the Cretaceous, busy remodeling the shape and tone of life on Earth. At the start of the period, dinosaurs ruled the loosening remnants of the supercontinent Pangaea as rodents scurried at their feet ...
What animals fought for scraps?
Smaller carnivores likely battled for the scraps. Other creatures, such as frogs, salamanders, turtles, crocodiles, and snakes, proliferated on the expanded coasts. Shrewlike mammals scurried about the forests.
What is the core of Mars?
Core of Mars is shockingly big, NASA mission reveals. Looking inside the red planet will help scientists better understand how Mars formed and became the hostile, rusty desert we see today. Chunk of an ancient supercontinent discovered under New Zealand. Science.
When did the Tyrannosaurus rex go extinct?
Tyrannosaurus rex arose during the Cretaceous period about 85 million years ago, and thrived as a top land predator until the dinosaurs went extinct 20 million years later.
Which dinosaurs ruled the southern continents?
Though dinosaurs ruled throughout the Cretaceous, the dominant groups shifted and many new types evolved. Sauropods dominated the southern continents but became rare in the north. Herd-dwelling ornithischians like Iguanodon spread everywhere but Antarctica.
What was the end of the Cretaceous?
The Cretaceous Period ends with one of the greatest known extinction events, so severe it also marks the end of the Mesozoic Era . Dinosaurs, pterosaurs, mosasaurs, and ammonoids, to name a few, were among the groups lost at this time.
What was the largest land predator in the mollusk period?
Rudist mollusks build new reefs rivaling today's coral reefs. This Period saw the emergence of the largest of all known land predators, such as Tyrannosaurus Rex, and the largest flying animal, Quetzalcoatlus.
What was the first plant to emerge in the Cretaceous?
The Cretaceous* saw the first appearance and initial diversification of flowering plants (Angiosperms ). Insects and other organisms soon evolve to take advantage of the new food sources and opportunities these plants provide. Conifers continued replacing seed ferns, ginkgos and cycads. Marine life flourished, with many groups achieving their peak abundances and diversity. Rudist mollusks build new reefs rivaling today's coral reefs. This Period saw the emergence of the largest of all known land predators, such as Tyrannosaurus Rex, and the largest flying animal, Quetzalcoatlus. Reptiles dominated the land (dinosaurs), the sea (mososaurs and the giant turtle, archelon) and the air (pterosaurs). Duck-billed dinosaurs are the commonest ornithischians.
What was the backdrop for the Paleozoic era?
Massive Volcanism at the end of the Paleozoic Era forms a backdrop for a scene including Hadrosaurs, a Tyrannosaur, Quezalcoatlus, Tricerotops, and an Ankylosaur. Plants include firs, cycads and an early magnolia tree in flower.
What is a Mosasaur egg?
reptile egg. Mosasaur (Mosasauridae<Squamata<Reptilia) A museum-quality model of a Tylosaurus, a huge predatory marine lizard, chasing a large ammonite, sits on top of the case . Tylosaurus was one of the largest of the mosasaurs , reaching lengths of 50 ft or more.
What is a ray-finned fish?
Ray-finned fish. Ray-finned fish (Actinopterigii), The teleost fish (teleosti), for example Rhacholepis buccalis, which dominate modern groups, appeared first in the Jurassic. In the Cretaceous they first outnumber the earlier fish types. Rhacholepis buccalis.
What caused the Cretaceous Extinction?
The Cretaceous extinction event is marked by the famous K-T boundary and asteroid impact on what is now the Yucatan peninsula. Many believe this impact caused dinosaur and other extinctions. Other possible causes, including extensive volcanic eruptions (the Deccan Traps in India) occur at this time.
Previous period
The Jurassic Period began 201 million years ago and ended 145 million years ago.
Cretaceous Period Division
The Lower Cretaceous begins after the end of the Jurassic, 145 million years ago.
Geological characteristics of the Cretaceous
During the Cretaceous there was a significant increase in the level of the waters , which at its maximum point left out only 18% of the planet ‘s surface . On the other hand, important mountain ranges such as the North American mountain range , the Andes and the Himalayas originated.
Characteristics of the Cretaceous flora
In the Early Cretaceous, a revolutionary event took place in the botanical world: angiosperms, that is, plants with flowers, seeds and fruits, appeared . And their evolutionary success was such that in just 20 million years the pollen levels of these plants increased from 1% to 40%.
Formation of oil fields
Another important feature is that in the Cretaceous the material was formed that later constituted the large oil reserves of the entire world, more than 50% of what we know today. Especially the reserves of the Persian Gulf, the Gulf of Mexico and the coasts of Venezuela were formed throughout this period.
Importance of the end of the dinosaurs
The disappearance of the dinosaurs allowed the flourishing of mammals.
The Cenozoic era
After the end of the Cretaceous, the Mesozoic Era closes and the Cenozoic Era opens, formerly known as the Tertiary. Significant cooling of the planet occurred which then led to future ice ages.
What was the end of the Cretaceous?
Globally, the end of the Cretaceous saw one of the greatest continental magmatism on earth--the Deccan flood basalts, tremendous outpourings within a span of some five million years. The KT boundary is an important marker in geological history. There may have been large asteroid impact (s) during the Late Cretaceous. The dinosaurs disappeared with the end of the Cretaceous. Cretaceous is also very important In the context of Himalayan geology, A series of island arcs (Chagai, Kohistan, Ladakh, southern Tibet) developed in the Neotethys during the Cretaceous. The Kohistan (and Ladakh) arc became an Andean type margin in the Late Cretaceous (90-100 Ma) after collision with the Karakoram plate. I think earliest contact between NW India and Kohistan arc may have taken place at Creto-Paleocene boundary. Many of our ophiolites were emplaced in Paleocene.
What were the major events of the Cretaceous?
There were a lot of great events in Cretaceous, for example opening of Arctic ocean, Mesozoic folding at the North East Asia. In addition most of porphyric deposits were formed in Crtaceous etc.
What animals moved through the forest?
In some ways, things went on as they had. Dinosaurs both great and small moved through forests of ferns, cycads, and conifers. Ammonites, belemnites, other molluscs, and fish were hunted by great "marine reptiles," and pterosaurs and birds flapped and soared in the air above.
What organisms sailed through the Cretaceous-Tertiary boundary?
But many groups of organisms, such as flowering plants, gastropods and pelecypods (snails and clams), amphibians, lizards and snakes, crocodilians, and mammals "sailed through" the Cretaceous-Tertiary boundary, with few or no apparent extinctions at all.
What was the most famous mass extinction?
The most famous of all mass extinctions marks the end of the Cretaceous Period, about 65 million years ago. As everyone knows, this was the great extinction in which the dinosaurs died out, except for the birds, of course. The other lineages of "marine reptiles" — the ichthyosaurs, plesiosaurs, and mosasaurs — also were extinct by the end ...
What insects were found in the Cretaceous?
At about the same time, many modern groups of insects were beginning to diversify, and we find the oldest known ants and butterflies. Aphids, grasshoppers, and gall wasps appear in the Cretaceous, as well as termites and ants in the later part of this period.
What are the environments that angiosperms thrive in?
The angiosperms thrived in a variety of environments such as areas with damper climates, habitats favored by cycads and cycadeoids, and riparian zones. High southern latitudes were not invaded by angiosperms until the end of the Cretaceous. Ferns dominated open, dry and/or low-nutrient lands.
What was the end of the Cretaceous?
The end of the Cretaceous brought the end of many previously successful and diverse groups of organisms, such as non-avian dinosaurs and ammonites. This laid open the stage for those groups which had previously taken secondary roles to come to the forefront.
What is the Cretaceous period?
The Cretaceous Period. Online exhibits : Geologic time scale : Mesozoic Era. The Cretaceous Period. The Cretaceous is usually noted for being the last portion of the "Age of Dinosaurs", but that does not mean that new kinds of dinosaurs did not appear then. It is during the Cretaceous that the first ceratopsian and pachycepalosaurid dinosaurs ...
Previous Period
Cretaceous Period Division
Geological Characteristics of The Cretaceous
Climatic Characteristics of The Cretaceous
Characteristics of The Cretaceous Flora
Characteristics of The Cretaceous Fauna
Mass Extinction Or Kt Or K/Pg Event
Formation of Oil Fields
- Another important feature is that in the Cretaceous the material was formed that later constituted the large oil reserves of the entire world, more than 50% of what we know today. Especially the reserves of the Persian Gulf, the Gulf of Mexico and the coasts of Venezuela were formed throughout this period.
Importance of The End of The Dinosaurs
The Cenozoic Era