When was the Cretaceous period?
Geology of Saskatchewan
The Cretaceous 144-66 Ma to Miocene periods deposited clastic sediments from the Cordilleran orogeny. This period saw 40% of the region now called North America below sea level under the Rocky Mountain Seaway which comprised the Western Interior Seaway and the Hudson Seaway, and Labrador Seaway. The Cretaceous period rocks produce medium and heavy gravity oil in the Lloydminster region, and of the western province. The Laramide orogeny episode near the end of the Cretacsous and early Tertiary period caused larger gravels to be deposited from the newly formed Rocky Mountains when the Kula and Farallon Plates subducted below the North American plate. In the Cypress Hills area and southern Saskatchewan, lignite deposits developed from the marshes of these Tertiary rivers. The sea waters have retreated from the areas known as Saskatchewan. The Ravenscrag formation, Cypress Hills, and Wood Mountain Formations were notable gravel deposits from the Tertiary period. The Williston Basin affects this region at the southern edge. Tectonic movements and global changes in the sea level have given rise to a source of oil, natural gas, and coal.
History of Crete
Because of a lack of written records, estimates of Cretan chronology are based on well-established Aegean and Ancient Near Eastern pottery styles, so that Cretan timelines have been made by seeking Cretan artifacts traded with other civilizations (such as the Egyptians) – a well established occurrence. For the earlier times, radiocarbon dating of organic remains and charcoal offers independent dates. Based on this, it is thought that Crete was inhabited from the 7th millennium BC onwards.
Beetle
Many fossil sites worldwide contain beetles from the Cretaceous. Most are in Europe and Asia and belong to the temperate climate zone during the Cretaceous. Lower Cretaceous sites include the Crato fossil beds in the Araripe basin in the Ceará, North Brazil, as well as overlying Santana formation; the latter was near the equator at that time. In Spain, important sites are near Montsec and Las Hoyas. In Australia, the Koonwarra fossil beds of the Korumburra group, South Gippsland, Victoria, are noteworthy. Major sites from the Upper Cretaceous include Kzyl-Dzhar in South Kazakhstan and Arkagala in Russia.
Cretaceous
The Cretaceous is divided into Early and Late Cretaceous epochs, or Lower and Upper Cretaceous series. In older literature the Cretaceous is sometimes divided into three series: Neocomian (lower/early), Gallic (middle) and Senonian (upper/late). A subdivision in eleven stages, all originating from European stratigraphy, is now used worldwide. In many parts of the world, alternative local subdivisions are still in use.
Bagaceratopidae
Bagaceratopids existed during the late Cretaceous period, between about 85.8 and 70.6 million years ago.
South Polar region of the Cretaceous
In the Early Cretaceous, East Gondwana (Australia, Antarctica and Zealandia) had started to split away from South America, and India and Madagascar also began to separate at around the same time. The tropical zone may have extended, during the Cretaceous, to 32°S, allowing year-round tree growth in the Antarctic in polar forests. The discovery of several mature evergreen and deciduous trees indicate a warm-to-cool temperature with moderate seasons lacking widespread freezing, at least between the latitudes 70 and 85°S. However, it is also possible that the plant life may only be representative of the warm summer months. Much of what is known of the plant life of East Gondwana during the Cretaceous consists of pollen remains and leaf compressions from the northern Antarctic Peninsula. Depending on the latitude, the polar winters may have lasted from six weeks to four and a half months.
However, rocks from the Early Cretaceous Wonthaggi Formation in southeastern Australia evidence seasonally frozen ground. Its geographical positioning in the Early Cretaceous at around 78°S indicates this area experienced one to three months of darkness in winters, and this area is representative of a glacial-fed floodplain. Evidence of Early Cretaceous glaciation and cold climates was discovered in sediments in the Eromanga Basin in modern-day central Australia, or 60 to 80°S in the Early Cretaceous. This basin was a large inland sea in the Cretaceous. Nonetheless, similar formations could have been created by simply debris flow, and so it is possible that glaciation did not ever occur there. The total polar ice coverage during the Mesozoic may have been a third of the size as it is in modern times, though cold snaps of subfreezing temperatures possibly occurred throughout the Early Cretaceous.
Phanerozoic
The Early Cretaceous Epoch spans from 145 million to 100 million years ago. The Early Cretaceous saw the expansion of seaways, and as a result, the decline and extinction of sauropods (except in South America). Many coastal shallows were created, and that caused ichthyosaurs to die out. Mosasaurs evolved to replace them as apex species of the seas. Some island-hopping dinosaurs, like "Eustreptospondylus", evolved to cope with the coastal shallows and small islands of ancient Europe. Other dinosaurs, such as "Carcharodontosaurus" and "Spinosaurus", rose to fill the empty space that the Jurassic-Cretaceous extinction had created. Of the most successful would be the "Iguanodon" which spread to every continent. Seasons came back into effect and the poles grew seasonally colder. Dinosaurs such as the "Leaellynasaura" inhabited the polar forests year-round, while many dinosaurs, such as the "Muttaburrasaurus", migrated there during summer . Since it was too cold for crocodiles, it was the last stronghold for large amphibians, such as the "Koolasuchus". In this epoch Pterosaurs reached their maximum diversity and grew larger, as species like "Tapejara" and "Ornithocheirus" took to the skies. The first true birds evolved, possibly sparking competition between them and the pterosaurs.
Geologic temperature record
The Phanerozoic eon, encompassing the last 542 million years and almost the entire time since the origination of complex multi-cellular life, has more generally been a period of fluctuating temperature between ice ages, such as the current age, and "climate optima", similar to what occurred in the Cretaceous. Roughly 4 such cycles have occurred during this time with an approximately 140 million year separation between climate optima. In addition to the present, ice ages have occurred during the Permian-Carboniferous interval and the late Ordovician-early Silurian. There is also a "cooler" interval during the Jurassic and early Cretaceous, with evidence of increased sea ice, but the lack of continents at either pole during this interval prevented the formation of continental ice sheets and consequently this is usually not regarded as a full-fledged ice age. In between these cold period, warmer conditions were present and often referred to as climate optima. However, it has been difficult to determine whether these warmer intervals were actually hotter or colder than occurred during the Cretaceous optima.
Geology of the southern North Sea
The break up of Pangea occurs during the Kimmerian tectonic phase for most of the Mesozoic, until the early-mid Cretaceous, this marks the start of creating the present position of our continents today. During the Jurassic, rifting activity reaches its maximum and North America starts to move apart from Eurasia following that event in the Cretaceous the southern part of North America starts to open up the Atlantic Ocean with the separation of South America and Africa. At the end of the Mesozoic the North Sea reached its final position where it lies in present day. Throughout the Cretaceous rifting eventually slowed down and came to a halt which later created the North Sea failed rift system because the regional stresses had shifted on to North America. The Jurassic is probably the most important geological time for hydrocarbon exploration in the North Sea. Many accumulations are in Jurassic reservoir, the Kimmeridge clay is considered the most important source rock and structures formed during rifting form excellent traps. In the first place rifting was responsible for the deposition of organic rich source rock due to anoxic conditions in the deep isolated rift basins. Possibly the most important phase to create structures and traps for the natural resources we try to collect today.
South Polar region of the Cretaceous
Evidence of flowering plants dating to around 80 Ma in the Late Cretaceous suggests the existence of temperate forests–similar to those in present-day Australia, New Zealand, and southern South America. Some flower remains were discovered near 60°S, and it is possible at such a low latitude that this area was subject to polar winters and seasonal weather, though the flowers suggest an annual temperature range of and a rainy climate.
Climate across Cretaceous–Paleogene boundary
The Paleocene (the first epoch of the Paleogene) immediately followed the asteroid impact that destroyed the dinosaurs and the Cretaceous world. It marks the transition between the dinosaurs of the Mesozoic and the emergence of the larger mammals of the Eocene (Cenozoic). The early part of the period experienced cooler temperatures and a more arid climate than existed before the asteroid. This is most likely due to atmospheric dust reflecting sunlight for an extended time. But in the latter part of the epoch, the temperatures warmed significantly, resulting in the absence of glaciated poles and the presence of verdant, tropical forests. The warmer climate increased ocean temperatures leading to a proliferation of species such as coral and other invertebrates.
Cretaceous
Late Cretaceous
Prehistoric Planet
220,000,000 BC, Late Triassic (Arizona) − This episode follows the evolution of the first dinosaurs and other prehistoric creatures in the late Triassic period.152,000,000 BC, Late Jurassic (Colorado) − This episode follows the story of a young female "Diplodocus" and her brothers and sisters in the late Jurassic period.149,000,000 BC, Late Jurassic (Oxfordshire) − This episode follows the life of several baby "Ophthalmosaurus" and a bull "Liopleurodon" in the late Jurassic period.127,000,000 BC, Early Cretaceous (Brazil) − This episode follows a male "Ornithocheirus" on his long journey to the mating grounds in the early Cretaceous period.106,000,000 BC, Early Cretaceous (Antarctica) − This episode follows the hardships of an Antarctican "Leaellynasaura" clan in the early Cretaceous period.65,500,000 BC, Late Cretaceous (Montana) − This episode follows the final years of the dinosaurs and a mother "Tyrannosaurus rex" and her babies in the late Cretaceous period.49,000,000 BC, Early Eocene (Germany) − This episode follows the life of a mother "Leptictidium" and her babies in the dense forests of Germany in the early Eocene epoch.36,000,000 BC, Late Eocene (Pakistan) − This episode follows the sea journey of a pregnant female "Basilosaurus" search for food in the late Eocene epoch.25,000,000 BC, Late Oligocene (Mongolia) − This episode follows the life of a young "Paraceratherium" and his mother from his birth in the late Oligocene epoch.3,200,000 BC, Late Pliocene (Ethiopia) − This episode follows the hardships of an "Australopithecus" group and a young called Blue in the late Pliocene epoch.1,000,000 BC, Early Pleistocene (Paraguay) − This episode follows a male "Smilodon" called Half-Tooth after he lost his territory in the early Pleistocene epoch.30,000 BC, Late Pleistocene (North Sea, Belgium, and Swiss Alps) − This episode follows a herd of woolly mammoth journey to the Alps in the last Ice Age of the late Pleistocene epoch.This episode details a list of animals from the first season that the developers thought were the most impressive creatures on Earth.
Geologic time scale
Evidence from radiometric dating indicates that Earth is about 4.54 billion years old. The geology or "deep time" of Earth's past has been organized into various units according to events which took place. Different spans of time on the GTS are usually marked by corresponding changes in the composition of strata which indicate major geological or paleontological events, such as mass extinctions. For example, the boundary between the Cretaceous period and the Paleogene period is defined by the Cretaceous–Paleogene extinction event, which marked the demise of the non-avian dinosaurs and many other groups of life. Older time spans, which predate the reliable fossil record (before the Proterozoic eon), are defined by their absolute age.
Evolution of dinosaurs
The Cretaceous sauropods form two groups. The Diplodocoidea lived from 121 to 66 Ma. The Titanosauriformes lived from 132 to 66 Ma. The latter clade consists of series of nested subgroups, the Titanosauria, the Titanosauridae and Saltasauridae. Both the Diplodocoidea and Titanosauriformes are descended from the Neosauropoda, the earliest of which lived in about 169 Ma.
Cretaceous Terrestrial Revolution
Before the paper described the KTR, it had been widely accepted in paleontology that new families of dinosaurs evolved during Mid to Late Cretaceous, including the euhadrosaurs, neoceratopsians, ankylosaurids, pachycephalosaurs, caracharodontosaurines, troodontids, dromaeosaurs, and ornithomimosaurs. However, the authors of the paper have suggested that the apparent "new diversification" of dinosaurs during this time is due to sampling biases in the fossil record, and better preserved fossils in Cretaceous age sediments than in earlier Triassic or Jurassic sediments.
Holocene
The Holocene climatic optimum (HCO) was a period of warming in which the global climate became warmer. However, the warming was probably not uniform across the world. This period of warmth ended about 5,500 years ago with the descent into the Neoglacial and concomitant Neopluvial. At that time, the climate was not unlike today's, but there was a slightly warmer period from the 10th–14th centuries known as the Medieval Warm Period. This was followed by the Little Ice Age, from the 13th or 14th century to the mid-19th century, which was a period of cooling.
Timeline of Cretaceous–Paleogene extinction event research
Paleontologists have recognized that a significant transition occurred between the Mesozoic and Cenozoic eras at least since the . Around this time dinosaur fossils were first being described in the scientific literature. Nevertheless, so few dinosaurs were known that the significance of their passing went unrecognized and little scientific effort was exerted toward finding an explanation. As more and more different kinds of dinosaurs were discovered, their extinction and replacement by mammals was recognized as significant but dismissed with little examination as a natural consequence of the mammals' supposed innate superiority. Consequently, paleontologist Michael J. Benton has called the years up to 1920 as the "Nonquestion Phase" of Cretaceous–Paleogene extinction research.
Polar forests of the Cretaceous
During the Cretaceous, temperate forests thrived at polar latitudes, as there was a notable difference from current conditions at high latitudes during the Cretaceous polar seasons. The duration of summer sunlight and winter darkness lasted for approximately 5 months each. This variation in light is thought to have played a critical role in the composition and evolution of polar forests. Fossilized flora evidence suggests the presence of paleoforests up to latitudes of 85° in both Northern and Southern hemispheres. The dominant forms of vegetation at these high latitudes during the previous 100 million years were rapidly evolving and ultimately being replaced during a time known as the Cretaceous Terrestrial Revolution. During the Cretaceous Terrestrial Revolution, conifers, cycads and ferns were selectively replaced by angiosperms and gymnosperms, becoming the main species dominating the high paleolatitudes. In this Cretaceous greenhouse world, Arctic conifer forests were considered predominantly deciduous, while those that grew on Antarctica contained a significantly greater proportion of evergreens.
List of North American dinosaurs
Finally, the Late Cretaceous Period, the greatest abundance and diversity of dinosaurs of all time lived in North America. During the early part of the Late Cretaceous, the therizinosaur "Nothronychus" and the ceratopsian "Zuniceratops" lived. During the Campanian stage of the Late Cretaceous, an enormous diversity of dinosaurs is known. Theropods included the tyrannosaurs "Albertosaurus", "Gorgosaurus", "Daspletosaurus", "Teratophoneus", "Bistahieversor", and "Appalachiosaurus", and the dromaeosaurids "Dromaeosaurus", "Saurornitholestes", "Atrociraptor", and "Bambiraptor". Ceratopsians, such as "Pachyrhinosaurus", "Styracosaurus", "Centrosaurus", "Monoclonius", "Brachyceratops" and "Pentaceratops" also existed. Among hadrosaurs," Hypacrosaurus, Gryposaurus, Kritosaurus, Parasaurolophus", "Corythosaurus", "Lambeosaurus" and "Prosaurolophus" existed. During the latest Cretaceous, the Maastrichtian age, the diversity of dinosaurs saw a decline from the preceding Campanian stage. North American herbivorous dinosaurs from this time period include the titanosaur sauropod "Alamosaurus", the ceratopsians "Bravoceratops", "Regaliceratops", "Triceratops", "Leptoceratops", "Torosaurus", "Nedoceratops", "Tatankaceratops" (the latter two possible species of "Triceratops"), and "Ojoceratops", the pachycephalosaurs "Pachycephalosaurus", "Stygimoloch", "Dracorex", and "Sphaerotholus", the hadrosaurs "Augustynolophus", "Saurolophus" and "Edmontosaurus", the ornithopod "Thescelosaurus" the ankylosaur "Ankylosaurus" and the nodosaurs "Denversaurus", "Glyptodontopelta" and "Edmontonia". Predatory dinosaurs from this time period included the tyrannosaurids "Tyrannosaurus", "Nanotyrannus" (which may just be a juvenile of the former) and "Dryptosaurus", the ornithomimids "Ornithomimus" and "Struthiomimus," the oviraptorids "Anzu", "Leptorhynchos" and "Ojoraptorsaurus", the troodontids "Pectinodon", "Paronychodon" and "Troodon", the coelurosaur "Richardoestesia" and the dromaeosaurs "Acheroraptor" and "Dakotaraptor".
Cretaceous
The Cretaceous is justly famous for its chalk; indeed, more chalk formed in the Cretaceous than in any other period in the Phanerozoic. Mid-ocean ridge activity—or rather, the circulation of seawater through the enlarged ridges—enriched the oceans in calcium; this made the oceans more saturated, as well as increased the bioavailability of the element for calcareous nanoplankton. These widespread carbonates and other sedimentary deposits make the Cretaceous rock record especially fine. Famous formations from North America include the rich marine fossils of Kansas's Smoky Hill Chalk Member and the terrestrial fauna of the late Cretaceous Hell Creek Formation. Other important Cretaceous exposures occur in Europe (e.g., the Weald) and China (the Yixian Formation). In the area that is now India, massive lava beds called the Deccan Traps were erupted in the very late Cretaceous and early Paleocene.
Late Cretaceous
The Cretaceous–Paleogene extinction event was a large-scale mass extinction of animal and plant species in a geologically short period of time, approximately (Ma). It is widely known as the "K–T extinction event" and is associated with a geological signature, usually a thin band dated to that time and found in various parts of the world, known as the Cretaceous–Paleogene boundary (K–T boundary). "K" is the traditional abbreviation for the Cretaceous Period derived from the German name "Kreidezeit", and "T" is the abbreviation for the Tertiary Period (a historical term for the period of time now covered by the Paleogene and Neogene periods). The event marks the end of the Mesozoic Era and the beginning of the Cenozoic Era. "Tertiary" being no longer recognized as a formal time or rock unit by the International Commission on Stratigraphy, the K-T event is now called the Cretaceous—Paleogene (or K-Pg) extinction event by many researchers.
Late Cretaceous
Near the end of the Cretaceous Period, flowering plants diversified. In temperate regions, familiar plants like magnolias, sassafras, roses, redwoods, and willows could be found in abundance.
Mesoamerican Archaic period
The Archaic period, also known as the preceramic period, is a period in Mesoamerican chronology that begins around 8000 BCE and ends around 2000 BCE and is generally divided into Early, Middle, and Late Archaic periods. The period is preceded by the Paleoindian (or Lithic) period and followed by the Preclassic period. Scholars have found it difficult to determine exactly when the Paleoindian period ends and the Archaic begins, but it is generally linked with changing climate associated with the transition from the Pleistocene to the Holocene epochs, and absence of extinct Pleistocene animals. It is also generally unclear when the Archaic period ends and the Preclassic period begins, though the appearance of pottery, large-scale agriculture, and villages signal the transition.
Pleistocene
In 2009 the International Union of Geological Sciences (IUGS) confirmed a change in time period for the Pleistocene, changing the start date from 1.806 to 2.588 million years BP, and accepted the base of the Gelasian as the base of the Pleistocene, namely the base of the Monte San Nicola GSSP. The IUGS has yet to approve a type section, Global Boundary Stratotype Section and Point (GSSP), for the upper Pleistocene/Holocene boundary ("i.e." the upper boundary). The proposed section is the "North Greenland Ice Core Project" ice core 75° 06' N 42° 18' W. The lower boundary of the Pleistocene Series is formally defined magnetostratigraphically as the base of the Matuyama (C2r) chronozone, isotopic stage 103. Above this point there are notable extinctions of the calcareous nanofossils: "Discoaster pentaradiatus" and "Discoaster surculus".
Timeline of Cretaceous–Paleogene extinction event research
Since the 19th century, a significant amount of research has been conducted on the Cretaceous–Paleogene extinction event, the mass extinction that ended the dinosaur-dominated Mesozoic Era and set the stage for the Age of Mammals, or Cenozoic Era. A chronology of this research is presented here.
Cycladic culture
Cycladic culture (also known as Cycladic civilisation or, chronologically, as Cycladic chronology) was a Bronze Age culture (c. 3200–c. 1050 BC) found throughout the islands of the Cyclades in the Aegean Sea. In chronological terms, it is a relative dating system for artefacts which broadly complements Helladic chronology (mainland Greece) and Minoan chronology (Crete) during the same period of time.
Geologic temperature record
During the later portion of the Cretaceous, from , average global temperatures reached their highest level during the last ~200 million years. This is likely to be the result of a favorable configuration of the continents during this period that allowed for improved circulation in the oceans and discouraged the formation of large scale ice sheet. Perhaps the visible anecdotal evidence of high temperatures during this period was the occurrence of deciduous forests extending all the way to the poles.
Cretaceous Thermal Maximum
The Cretaceous Thermal Maximum (CTM), also known as Cretaceous Thermal Optimum, was a period of climatic warming that reached its peak approximately 90 million years ago (90 Ma) during the Turonian age of the Late Cretaceous epoch. The CTM is notable for its dramatic increase in global temperatures characterized by high carbon dioxide levels.
During the Cretaceous Thermal Maximum (CTM), atmospheric carbon dioxide levels rose to over 1000 parts per million compared to the pre-industrial average of 280 ppm. Rising carbon dioxide resulted in a significant increase in the greenhouse effect, leading to elevated global temperatures. In the seas, crystalline or "glassy" foraminifera predominated, a key indicator of higher temperatures. The CTM began during the Cenomanian/Turonian transition and was associated with a major disruption in global climate as well as global anoxia during Oceanic Anoxic Event 2 (OAE-2). The CTM was the most extreme disruption of the carbon cycle in the past 100 million years.
Rebbachisauridae
So far, rebbachisaurids are known only from the middle and early part of the Late Cretaceous. Unless the nemegtosaurids are in fact diplodocoids (rather than titanosaurs), then the rebbachisaurids represent the last known representatives of this clade, and lived alongside the titanosaurs until fairly late in the Cretaceous. So far, no rebbachisaurids are known from the very end of the Cretaceous period.
Utahceratops
The only known specimen of "Utahceratops" was recovered at the Kaiparowits Formation, in Utah. Argon-argon radiometric dating indicates that the Kaiparowits Formation was deposited between 76.6 and 74.5 million years ago, during the Campanian stage of the Late Cretaceous period. During the Late Cretaceous period, the site of the Kaiparowits Formation was located near the western shore of the Western Interior Seaway, a large inland sea that split North America into two landmasses, Laramidia to the west and Appalachia to the east. The plateau where dinosaurs lived was an ancient floodplain dominated by large channels and abundant wetland peat swamps, ponds and lakes, and was bordered by highlands. The climate was wet and humid, and supported an abundant and diverse range of organisms. This formation contains one of the best and most continuous records of Late Cretaceous terrestrial life in the world.
Phanerozoic
The Late Cretaceous Epoch spans from 100 million to 66 million years ago. The Late Cretaceous featured a cooling trend that would continue into the Cenozoic Era. Eventually, tropical ecology was restricted to the equator and areas beyond the tropic lines featured extreme seasonal changes of weather. Dinosaurs still thrived as new species such as "Tyrannosaurus", "Ankylosaurus", "Triceratops" and Hadrosaurs dominated the food web. Whether or not Pterosaurs went into a decline as birds radiated is debated, however many families survived until the end of the Cretaceous, alongside new species such as the gigantic "Quetzalcoatlus". Marsupials evolved within the large conifer forests as scavengers. In the oceans, Mosasaurs ruled the seas to fill the role of the ichthyosaurs, and huge plesiosaurs, such as "Elasmosaurus", evolved. Also, the first flowering plants evolved. At the end of the Cretaceous, the Deccan Traps and other volcanic eruptions were poisoning the atmosphere. As this was continued, it is thought that a large meteor smashed into Earth, creating the Chicxulub Crater creating the event known as the K-T Extinction, the fifth and most recent mass extinction event, during which 75% of life on Earth became extinct, including all non-avian dinosaurs. Every living thing with a body mass over 10 kilograms became extinct, and the age of the dinosaurs came to an end.
Maastrichtian (disambiguation)
The Maastrichtian is the last stage of the Cretaceous period, and therefore of the Mesozoic era.
Prehistory of the United States
The Cretaceous ended with another mass extinction. This one was the second most devastating in geologic history. Roughly half of all animal families became extinct. Ammonoids and belemnoids were among the marine invertebrates extinguished. Planktonic foraminiferans barely survived. Two thirds of coral species became extinct. About half of sponge families became extinct. Bivalves, bryozoans, and gastropods also sustained heavy losses. The major Mesozoic marine reptile groups became extinct. On land, the non-avian dinosaurs and pterosaurs became extinct. The most popular explanation for the mass extinction at the end of the Cretaceous is that it resulted from a meteorite impact. This impact would explain the presence of high levels of the heavy element iridium in sediments from the time. Iridium is very rare in earth's crust but much more common in meteors. Dinosaurs were widespread within the regions now composing the modern United States. Dinosaur fossils are known to have been preserved in Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Georgia, Idaho, Iowa, Kansas, Louisiana, Maryland, Massachusetts, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, North Dakota, Oklahoma, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, D.C., and Wyoming, but not in Florida, Hawaii, Illinois, Indiana, Kentucky, Maine, Michigan, New Hampshire, Ohio, Oregon, Rhode Island, Vermont, Washington, West Virginia, or Wisconsin.
Cretolamna
These sharks lived from the Aptian of the Cretaceous period to the Ypresian stage of the early Eocene epoch (115 to 48 million years ago). It is considered by many to be the ancestor of many of the famous shark genera, such as the mako, great white, "Carcharocles angustidens", and "Carcharocles megalodon" sharks.
Cretaceous
The apex predators were archosaurian reptiles, especially dinosaurs, which were at their most diverse stage. Pterosaurs were common in the early and middle Cretaceous, but as the Cretaceous proceeded they declined for poorly understood reasons (once thought to be due to competition with early birds, but now it is understood avian adaptive radiation is not consistent with pterosaur decline), and by the end of the period only two highly specialized families remained.
Outline of dinosaurs
Dinosaurs – diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period (about 230 million years ago) until the end of the Cretaceous (66 million years ago), when the Cretaceous–Paleogene extinction event led to the extinction of all non-avian dinosaurs at the close of the Mesozoic era. The fossil record indicates that birds evolved within theropod dinosaurs during the Jurassic period. Some of them survived the Cretaceous–Paleogene extinction event, including the ancestors of all modern birds. Consequently, in modern classification systems, birds are considered dinosaurs—the only group which survived to the present day.
Art of Europe
The Minoan culture is regarded as the oldest civilization in Europe. The Minoan culture existed in Crete and consisted of four periods: Prepalatial, Protopalatial, Neopalatial, and the Postpalatial period between 3650 BC and 1100 BC. Not much of the art remained from the Prepalatial times, and most of artefacts still existing today are Cycladic statuettes and pottery fragments. The most prosperous period of the Cretan civilization was Neopalatial period and most of the artefacts are from this era. A large number of artefacts from the Protopalatial can be seen today in Cretan museums.
Pottery – most popular in the Protopalatial period (1900-1700 BC) – was characterized by thin walled vessels, subtle, symmetrical shapes, elegant spouts, and decorations, and dynamic lines. Dark and light values were often contrasted in Minoan pottery. The spontaneity and fluidity of the Protopalatial period later were transformed to a more stylized form of art with dissociation of naturalism in the Neopalatial period.The palaces served as organizational, commercial, artistic, worshipping, and agricultural centres in the Cretan civilization. Cretan palaces were built without defensive walls and exhibited a central courtyard which was embraced by a number of buildings. The central courtyard served as the main meeting place of the people. The palaces had throne rooms, cult chambers, and theatres where people could gather at special events. Columns and staircases were part of the artistic expression and it is believed that they served as metaphorical elements.The Minoan palaces are richly painted with paintings. Minoan painting was unique in that it used wet fresco techniques; it was characterized by small waists, fluidity, and vitality of the figures and was seasoned with elasticity, spontaneity, vitality, and high-contrasting colours.Not much of the sculpture survived from the Minoan civilization. The best known example of sculptures is the Snake Goddess figurine. The sculpture depicts a goddess or a high priestess holding a snake in both hands, dressed in traditional Minoan attire, cloth covering the whole body and leaving the breasts exposed. Exquisite metal work was also a characteristic of the Minoan art. Minoan metal masters worked with imported gold and copper and mastered techniques of wax casting, embossing, gilding, nielo, and granulation.
Climate across Cretaceous–Paleogene boundary
The K–Pg (formerly K–T) boundary is a thin band of sediment that dates back to 66 million years ago, and is found as a consistent layer all over the planet in over 100 known different locations. K and T are the abbreviations for the Cretaceous and Tertiary periods, respectively, but the name Tertiary has been replaced by "Paleogene" as a formal time or rock unit by the International Commission on Stratigraphy, and Pg is now the abbreviation. This boundary marks the start of the Cenozoic Era. Non-avian dinosaur fossils are found only below the K–Pg boundary which indicates that they became extinct at this event. In addition, mosasaurs, plesiosaurs, pterosaurs and many species of plants and invertebrates do not occur above this boundary, indicating extinction. The boundary was found to be enriched in iridium many times greater than normal (30 times background in Italy and 160 times at Stevns, Denmark), most likely indicating an extraterrestrial event or volcanic activity associated with this interval. Rates of extinction and radiation varied across different clades of organisms.
Catastrophism
Over the past 25 years, a scientifically based catastrophism has gained wide acceptance with regard to certain events in the distant past. One impetus for this change came from the publication of a historic paper by Walter and Luis Alvarez in 1980. This paper suggested that a asteroid struck Earth 66 million years ago at the end of the Cretaceous period. The impact wiped out about 70% of all species, including the dinosaurs, leaving behind the Cretaceous–Paleogene boundary (K–T boundary). In 1990, a candidate crater marking the impact was identified at Chicxulub in the Yucatán Peninsula of Mexico.
Cretaceous–Paleogene extinction event
At present the most informative sequence of dinosaur-bearing rocks in the world from the K–Pg boundary is found in western North America, particularly the late Maastrichtian-age Hell Creek Formation of Montana. Comparison with the older Judith River Formation (Montana) and Dinosaur Park Formation (Alberta), which both date from approximately 75 Ma, provides information on the changes in dinosaur populations over the last 10 million years of the Cretaceous. However, these fossil beds are geographically limited, covering only part of one continent.
Jurassic
During the early Jurassic period, the supercontinent Pangaea broke up into the northern supercontinent Laurasia and the southern supercontinent Gondwana; the Gulf of Mexico opened in the new rift between North America and what is now Mexico's Yucatan Peninsula. The Jurassic North Atlantic Ocean was relatively narrow, while the South Atlantic did not open until the following Cretaceous period, when Gondwana itself rifted apart. The Tethys Sea closed, and the Neotethys basin appeared. Climates were warm, with no evidence of glaciation. As in the Triassic, there was apparently no land over either pole, and no extensive ice caps existed.
Rosids
Fossil rosids are known from the Cretaceous period. Molecular clock estimates indicate that the rosids originated in the Aptian or Albian stages of the Cretaceous, between 125 and 99.6 million years ago.
Timeline of Cretaceous–Paleogene extinction event research
Ideas that evolution might proceed along pre-ordained patterns or that evolutionary lineages might age, deteriorate, and die like individual animals became popular starting in the late , but were superseded by the Neo-Darwinian synthesis. The aftermath of this transition brought renewed interest to the extinction at the end of the Cretaceous. Paleontologists began dabbling in the subject, proposing environmental changes during the Cretaceous like mountain-building, dropping temperatures or volcanic eruptions as explanation for the extinction of the dinosaurs. Nevertheless, much of the research occurring during this period lacked rigor, evidential support or depended on tenuous assumptions. Michael J. Benton called the years between 1920 and 1970 the "Dilettante Phase" of Cretaceous–Paleogene extinction research.
Cretaceous
"Baculites", an ammonite genus with a straight shell, flourished in the seas along with reef-building rudist clams. The Hesperornithiformes were flightless, marine diving birds that swam like grebes. Globotruncanid Foraminifera and echinoderms such as sea urchins and starfish (sea stars) thrived. The first radiation of the diatoms (generally siliceous shelled, rather than calcareous) in the oceans occurred during the Cretaceous; freshwater diatoms did not appear until the Miocene. The Cretaceous was also an important interval in the evolution of bioerosion, the production of borings and scrapings in rocks, hardgrounds and shells.
Paleontology in Minnesota
The gap in the fossil record that began in the late Paleozoic spans the entire Triassic period of the ensuing Mesozoic era. However, during the ensuing Jurassic a sea once more intruded into the state. No fossils are known from sediments deposited by this sea. Minnesota played host to the northeastern corner of yet another sea during the ensuing Cretaceous period. Ammonites, clams, and oysters lived here. Ammonites and oysters were preserved in the Coleraine area. Contemporary gastropods and pelecypods left behind abundant fossils in what is now the Mesabi Range. Fish teeth and bones were preserved in Big Stone County. Sawfish lived in the state during the Cretaceous.
Atacama Fault
The AFZ has gone through periods of inactivity and reactivation since its inception in the Cretaceous. The fault series was formed through a complex series of tectonic regimes dating back to the Early Jurassic, when the Andean back-arc basin separated from the Pacific Ocean. Intra-arc ductile deformation occurred in the Late Jurassic, creating north-striking mylonitic shear zones. A belt formed through a compressive regime in the early Cretaceous, followed by a compression of the Andean basement in the mid-Cretaceous. There was a regime of extension from the Oligocene to Miocene, and finally large brittle reactivations took place from the Miocene to Present.
Cretaceous Research
Cretaceous Research is a bimonthly peer-reviewed scientific journal published by Elsevier. The journal focuses on topics dealing with the Cretaceous period and the Cretaceous–Paleogene boundary.
Cretaceous Terrestrial Revolution
The Cretaceous Terrestrial Revolution (abbreviated KTR) describes the intense diversification of angiosperms, insects, reptiles, birds, and mammals during the Middle to Late Cretaceous (125-80 mya).
Craterosaurus
Craterosaurus (meaning "krater reptile" or "bowl reptile") was a genus of stegosaurid dinosaur. It lived during the Early Cretaceous (Valanginian to Barremian stages) around 145-136 million years ago. Its fossils were found in England. "Craterosaurus" may actually be a junior synonym of "Regnosaurus", but only one fossil, a partial vertebra, was recovered.
Crete
The first human settlement in Crete dates before 130,000 years ago, during the Paleolithic age. Settlements dating to the aceramic Neolithic in the 7th millennium BC, used cattle, sheep, goats, pigs and dogs as well as domesticated cereals and legumes; ancient Knossos was the site of one of these major Neolithic (then later Minoan) sites. Other neolithic settlements include those at Kephala, Magasa, and Trapeza.
History of Earth
The Cenozoic ("new life") era began at  Ma, and is subdivided into the Paleogene, Neogene, and Quaternary periods. These three periods are further split into seven sub-divisions, with the Paleogene composed of The Paleocene, Eocene, and Oligocene, the Neogene divided into the Miocene, Pliocene, and the Quaternary composed of the Pleistocene, and Holocene. Mammals, birds, amphibians, crocodilians, turtles, and lepidosaurs survived the Cretaceous–Paleogene extinction event that killed off the non-avian dinosaurs and many other forms of life, and this is the era during which they diversified into their modern forms.
Bagaceratops
"Bagaceratops" belonged to the Ceratopsia, a group of herbivorous dinosaurs with parrot-like beaks which thrived in North America and Asia during the Cretaceous Period, which ended roughly 66 million years ago.
Prehistory of the United States
During the Late Cretaceous the Gulf of Mexico had expanded through North America until reaching Alaska. Up to half of the continent's modern surface area may have been submerged by this sea. This is called the Western Interior Seaway. It covered the majority of states like Texas, New Mexico, Oklahoma, Colorado, Kansas, Nebraska, the Dakotas, and Wyoming. The seafloor was smooth and probably never submerged by more than 600 feet of water. A great diversity of invertebrates flourished both on the bottom and in the water column. Examples include ammonites, giant clams, crinoids, rudists, and squid. Vertebrate life included bony fishes, mosasaurs, plesiosaurs, sharks, and turtles. Areas now occupied by the plains of the east coast from New Jersey southward as well as the Gulf coast region were covered in seawater during the Cretaceous. Sea levels reached their highest level in all of geologic history during the Cretaceous, although they declined before the period ended. Scleractinian corals were more diverse during the Cretaceous than they are today. Back then coral reefs formed along the Gulf coast. Rudist bivalves also constructed reefs in the Gulf coast region. Another bivalve, Exogyra, was so common its fossils are found in almost every Cretaceous marine deposit. During the Cretaceous, the dominant group of living fishes, the teleosts, first achieved ascendency over their holostean forebears. The aquatic toothed bird Hesperornis is the only known Cretaceous bird whose remains are found with any frequency in North America.
Cretaceous–Paleogene boundary
The Cretaceous–Paleogene (K–Pg) boundary, formerly known as the Cretaceous–Tertiary (K-T) boundary, is a geological signature, usually a thin band of rock. "K", the first letter of the German word "Kreide" (chalk), is the traditional abbreviation for the Cretaceous Period and "Pg" is the abbreviation for the Paleogene Period.
Cretaceous
The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites and rudists, while dinosaurs continued to dominate on land. During this time, new groups of mammals and birds, as well as flowering plants, appeared.
Tarfaya Basin
As sea levels began to rise again during the early Cretaceous, the exposed Jurassic shelf was flooded. Increased temperatures during the Cretaceous, along with increased erosion inland, resulted in the transport of large amounts of clastic materials. Fine-grained clastics formed the basis of deltaic complexes along the coastal margin. Increased accommodation space during highstands allowed for the deposition of silty material over the carbonates of the former Jurassic shelf. These silty materials eventually buried the carbonates as prograding deltas developed in the Early Cretaceous. Within these deltaic sequeneces, a number of shale units were deposited.
San Juan Basin
The Cretaceous was a time of three major transgressive-regressive cycles, as eustatic changes in sea-level caused fluctuations on the Western Interior Seaway's shoreline. The San Juan Basin was conveniently located in the western margin of the seaway and recorded these cycles in the stratigraphy (see "Stratigraphy" below). The western-most extent of the seaway (a.k.a. maximum transgression) was recorded by the "Lewis Shale", which eventually graded into the "Pictured Cliffs" and the "Fruitland Formation" as the shoreline made its final retreat.
Primate
The primate lineage is thought to go back at least near the Cretaceous–Paleogene boundary or around 63–74 (mya), even though the oldest known primates from the fossil record date to the Late Paleocene of Africa ("Altiatlasius") or the Paleocene-Eocene transition in the northern continents, c. 55 mya ("Cantius", "Donrussellia", "Altanius", "Plesiadapis" and "Teilhardina"). Other studies, including molecular clock studies, have estimated the origin of the primate branch to have been in the mid-Cretaceous period, around 85 mya.
Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch (or, in chronostratigraphy: the fifth of six stages in the Upper Cretaceous series). The Campanian spans the time from 83.6 ± 0.7 Ma to 72.1 ± 0.6 Ma (million years ago). It is preceded by the Santonian and it is followed by the Maastrichtian.
Lancian
The Lancian was a North American faunal stage of the Late Cretaceous. It was the final stage of the Cretaceous period in North America, lasting from approximately 68 to 66 million years ago.
Dinosaur
The Cretaceous–Paleogene extinction event, which occurred approximately 66 million years ago at the end of the Cretaceous period, caused the extinction of all dinosaur groups except for the neornithine birds. Some other diapsid groups, such as crocodilians, sebecosuchians, turtles, lizards, snakes, sphenodontians, and choristoderans, also survived the event.
Coniacian
The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous epoch or Upper Cretaceous series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded by the Turonian and followed by the Santonian.
Dromaeosaurinae
Most dromaeosaurines lived during the Cretaceous period, from the Barremian to the Maastrichtian stages. However, as stated previously, at least one taxon must have lived much earlier, during the Jurassic Period.
Geology of England
The Mesozoic comprises the Triassic, Jurassic and Cretaceous periods (251–66 Ma).
Ceratopsia
Ceratopsia or Ceratopia ( or ; Greek: "horned faces", Κερατόψια) is a group of herbivorous, beaked dinosaurs that thrived in what are now North America, Europe, and Asia, during the Cretaceous Period, although ancestral forms lived earlier, in the Jurassic. The earliest known ceratopsian, "Yinlong downsi", lived between 161.2 and 155.7 million years ago. The last ceratopsian species, "Triceratops prorsus", became extinct during the Cretaceous–Paleogene extinction event, .
Phanerozoic
The Miocene spans from 23.03 to 5.333 million years ago and is a period in which grass spread further across, effectively dominating a large portion of the world, diminishing forests in the process. Kelp forests evolved, leading to the evolution of new species, such as sea otters. During this time, perissodactyla thrived, and evolved into many different varieties. Alongside them were the apes, which evolved into a 30 species. Overall, arid and mountainous land dominated most of the world, as did grazers. The Tethys Sea finally closed with the creation of the Arabian Peninsula and in its wake left the Black, Red, Mediterranean and Caspian Seas. This only increased aridity. Many new plants evolved, and 95% of modern seed plants evolved in the mid-Miocene.
Japan Trench
During the Cretaceous (145.5-66 million years ago) to early Paleogene (66-23.03 ma), evidence of andesitic volcanism along with the development of a large syncline and a thickened sediment sequence indicate the possible development of a forearc basin. Activity during the Cretaceous included subduction events as well as extensive accretion of sediment to the Northeastern Japan Arc that continues today. Volcanism decreased during the early Paleogene (66 ma), exposing the thickened Cretaceous-Paleogene 160-km thick sediment sequence. Once this sediment sequence subsided, volcanism once again resumed.
Cretaceous
The Cretaceous as a separate period was first defined by Belgian geologist Jean d'Omalius d'Halloy in 1822, using strata in the Paris Basin and named for the extensive beds of chalk (calcium carbonate deposited by the shells of marine invertebrates, principally coccoliths), found in the upper Cretaceous of Western Europe. The name Cretaceous was derived from Latin "creta", meaning "chalk".
Cretaceous Dawn
Cretaceous Dawn is a science-fiction novel by sibling scientists Lisa M. Graziano and Michael S. A. Graziano, published in 2008 by Leapfrog Press (initially published as 'Hell Creek: 65 Million Years in the Past, the Journey Begins' under Trafford Publishing in 2006. The book contains 304 pages. Its story is set to a modern time and also to the prehistory of 65 million years ago (at the end of the Cretaceous era). It starts in the physics laboratory, where long-extinct beetles start to appear. Four people and a dog are then hurled 65 million years through the deep geologic time, to the ending era of the dinosaurs (Hell Creek formation), and the main character - paleontologist Julian Whitney and his companions - have only one chance for their own rescue.
Cretaceous
A 140 Ma age for the Jurassic-Cretaceous boundary instead of the usually accepted 145 Ma was proposed in 2014 based on a stratigraphic study of Vaca Muerta Formation in Neuquén Basin, Argentina. Víctor Ramos, one of the authors of the study proposing the 140 Ma boundary age sees the study as a "first step" toward formally changing the age in the International Union of Geological Sciences.
Iridium
The [Cretaceous–Paleogene boundary] of 66 million years ago, marking the temporal border between the Cretaceous and Paleogene periods of geological time, was identified by a thin stratum of iridium-rich clay. A team led by Luis Alvarez proposed in 1980 an extraterrestrial origin for this iridium, attributing it to an asteroid or comet impact. Their theory, known as the Alvarez hypothesis, is now widely accepted to explain the extinction of the non-avian dinosaurs. A large buried impact crater structure with an estimated age of about 66 million years was later identified under what is now the Yucatán Peninsula (the Chicxulub crater). Dewey M. McLean and others argue that the iridium may have been of volcanic origin instead, because Earth's core is rich in iridium, and active volcanoes such as Piton de la Fournaise, in the island of Réunion, are still releasing iridium.
Silverpit crater
The position of the crater within the layers of rock and sediment on the sea floor could in theory be used to constrain its age: sediments laid down before the crater's formation might conceivably be disturbed by the impact, while those laid down afterwards will not. In their discovery paper, Allen and Stewart stated that Silverpit was formed in Cretaceous chalk and Jurassic shale, but is covered by an undisturbed layer of Paleogene sediment. The Cretaceous Period ended about 66 million years ago, but, on the evidence of nearby boreholes, the lowermost Paleogene sediments appear to be absent. Thus the age of the Silverpit event was initially stated to lie somewhere between 66 and 60 million years before present. However, after a more detailed apprasial of the seismic data, Allen and Stewart gave a more cautious estimate of the age as between 74 – 45 million years (Late Cretaceous – Eocene).
Calabrian (stage)
The end of the stage is defined by the last magnetic pole reversal (781 ± 5 Ka) and plunge into an ice age and global drying possibly colder and drier than the late Miocene (Messinian) through early Pliocene (Zanclean) cold period. Originally the Calabrian was a European faunal stage primarily based on mollusk fossils. It has become the second geologic age in the Early Pleistocene. Many of the mammalian faunal assemblages of the Early Pleistocene start in the Gelasian. For example, the Platygonus and other Blancan fauna appear first in the Gelasian.
Berriasian
In the geological timescale, the Berriasian is an age or stage of the Early Cretaceous. It is the oldest, or lowest, subdivision in the entire Cretaceous. It spanned the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago). The Berriasian succeeds the Tithonian (part of the Jurassic) and precedes the Valanginian.
Geological history of Earth
The Cretaceous Period extends from circa to .
Mesozoic
The Cretaceous is the longest period of the Mesozoic, but has only two epochs: Early and Late Cretaceous.
Neogene
The International Commission on Stratigraphy (ICS) once proposed that the Quaternary be considered a sub-era (sub-erathem) of the Neogene, with a beginning date of 2.58 Ma, namely the start of the Gelasian Stage. In the 2004 proposal of the ICS, the Neogene would have consisted of the Miocene and Pliocene epochs. The International Union for Quaternary Research (INQUA) counterproposed that the Neogene and the Pliocene end at 2.58 Ma, that the Gelasian be transferred to the Pleistocene, and the Quaternary be recognized as the third period in the Cenozoic, citing key changes in Earth's climate, oceans, and biota that occurred 2.58 Ma and its correspondence to the Gauss-Matuyama magnetostratigraphic boundary. In 2006 ICS and INQUA reached a compromise that made Quaternary a subera, subdividing Cenozoic into the old classical Tertiary and Quaternary, a compromise that was rejected by International Union of Geological Sciences because it split both Neogene and Pliocene in two.
Tertiary
Tertiary is the former term for the geologic period from 66 million to 2.58 million years ago, a timespan that occurs between the superseded Secondary period and the Quaternary. The Tertiary is no longer recognized as a formal unit by the International Commission on Stratigraphy, but the word is still widely used. The traditional span of the Tertiary has been divided between the Paleogene and Neogene periods and extends to the first stage of the Pleistocene Epoch, the Gelasian stage. 
The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start of the Cenozoic Era, and extended to the beginning of the Quaternary glaciation at the end of the Pliocene Epoch.
Geology of the United States
Once again, during the Cretaceous Period (144-65 million years ago), record high sea levels flooded the continental interior with shallow seas.
Yanshanian
The Yanshanian movement were first recognized by Weng WH (1927,1929) in the Yansan area of China (116°-119.5°N, 40°-42°E). Since then, the Yanshanian has been used as a local term in China for tectonic events which occurred mainly during the Jurassic Period. Later, Ding WJ (1929), Huang JQ (1945,1960) and Zhao ZF (1959) extended the term to cover tectonic events which occurred throughout China during the Jurassic and Cretaceous tectonic periods. However, it was soon realized that tectonic and magmatic events in the Jurassic and Cretaceous were very different. In the Jurassic there are NNE-NE trending folds and thrusts related to transpressional tectonics, and WNW trending normal faults with some strike-slip movement and widespread calc-alkaline magmatism, while the Cretaceous is characterized predominantly by extensional tectonics with NE-NNE trending normal faults, WNW trending folds and thrusts and highly alkaline acid magmatism located along faults, or at fault intersection.
Geology of the Bryce Canyon area
The exposed geology of the Bryce Canyon area in Utah shows a record of deposition that covers the last part of the Cretaceous Period and the first half of the Cenozoic era in that part of North America. The ancient depositional environment of the region around what is now Bryce Canyon National Park varied from the warm shallow sea (called the Cretaceous Seaway) in which the Dakota Sandstone and the Tropic Shale were deposited to the cool streams and lakes that contributed sediment to the colorful Claron Formation that dominates the park's amphitheaters.
Geology of Scotland
In the Cretaceous (145–66 Ma), Laurasia split into the continents of North America and Eurasia. Sea levels rose globally during this period and much of low-lying Scotland was covered in a layer of chalk. Although large deposits of Cretaceous rocks were laid down over Scotland, these have not survived erosion except in a few places on the west coast such as Loch Aline in Morvern where they form a part of the Inner Hebrides Group. At the end of this period the Cretaceous–Paleogene extinction event brought the age of dinosaurs to a close.
Cretaceous
Insects diversified during the Cretaceous, and the oldest known ants, termites and some lepidopterans, akin to butterflies and moths, appeared. Aphids, grasshoppers and gall wasps appeared.
Cretan wildcat
Crete has been isolated from the continent for about 6 million years. Palaeontological data indicate that the island was colonised during the Pleistocene by those mammalian taxa that were able to swim across the sea. Crete’s Pleistocene endemic mammalian fauna comprised rodents and herbivores, but remains of predators were not found. Pleistocene mammals died out before the Holocene.
More than 9,000 animal bones were excavated at the archaeological site Kavousi Kastro in eastern Crete in the late 1980s that date to the Late Geometric period at about 8th century BC. These faunal remains also included one cat that was identified as domestic cat.
Fragments of a domestic cat were also found at the archaeological site Gortyn dating to the 6th to 7th century AD.
Gallic epoch
The Gallic epoch is an obsolete epoch of the Mesozoic Era's Cretaceous, the latter being a geologic period and system that spans 79 million years from the end of the Jurassic Period million years ago (mya) to the beginning of the Paleogene Period mya. The Gallic epoch encompasses the Barremian, Aptian, Albian, Cenomanian and Turonian faunal stages.
Cymatoceratidae
Six genera are restricted to the Cretaceous; "Eucymatoceras" and "Heminautilus" from the Lower Cretaceous; "Anglonautilus" from both the Lower and Upper Cretaceous; "Deltocymatoceras", "Epicymatoceras",and "Syrionautilus". "Neocymatoceras" from the Oligocene from the Oligocene is synonymous with "Cymatoceras". 
Of the Cymatoceratidae, "Cymatoceras" has the longest temporal range, extending from the Late Jurassic to the Tertiary Oligocene. The only other to cross a period boundary is "Paracymatoceras" which lived during both the Late Jurassic and Early Cretaceous. The others are restricted to a simple period, sometimes to a single epoch.
Climate across Cretaceous–Paleogene boundary
The Cretaceous Period (145–66 Ma), overall, had a relatively warm climate which resulted in high eustatic sea levels and created numerous shallow inland seas. In the Late Cretaceous, the climate was much warmer than present; however, throughout most of the period, a cooling trend is apparent. The tropics were much warmer in the early Cretaceous and became much cooler toward the end of the Cretaceous.
Phanerozoic
The Cretaceous is the longest period in the Mesozoic, spans from 145 million to 66 million years ago, and is divided into two epochs: Early Cretaceous, and Late Cretaceous.
Late Pleistocene
The Late Pleistocene is a geochronological age of the Pleistocene Epoch and is associated with Upper Pleistocene (or Tarantian) stage rocks. The beginning of the stage is defined by the base of the Eemian interglacial phase before the final glacial episode of the Pleistocene 126,000 ± 5,000 years ago. Its end is defined at the end of the Younger Dryas, some 11,700 years ago. The age represents the end of the Pleistocene epoch and is followed by the Holocene epoch.
Lyelliceratidae
These cephalopods were fast-moving nektonic carnivores. They lived in the Cretaceous period (109.0 to 94.3 Ma).
Paleontology in Arkansas
Northern and central Arkansas was a terrestrial environment during the Triassic. However, by the early Jurassic seawater covered the southern region of the state. Southern and northeastern Arkansas were likewise covered by the sea into the Cretaceous. Local life left behind many fossils. During the Early Cretaceous, the region of Arkansas southeast of the Ouachita Mountains was submerged by the Gulf of Mexico. The invertebrates of Arkansas's Cretaceous sea included clams, echinoids, oysters, and snails. During the Cretaceous, Arkansas was home to "Belemnitella", "Exogyra", "Ostrea", "Turritella", and other marine invertebrates in the Arkadelphia area of Clark County. Fish of the same age left behind teeth in the area near Saratoga in Hempstead County. Other fossils in this area are similar to those of the preserved in contemporary deposits near Arkadelphia. During the Cretaceous Arkansas was home to the sea turtle "Bothremys", which may have fed on ancient snails. During the Late Cretaceous the region now occupied by the Quachita Mountains of Arkansas may have attracted long necked plesiosaurs from hundreds of miles away as a source of gastroliths. Other vertebrates included sharks.
Southwestern Arkansas was part of the coastline to the Western Interior Seaway during the Cretaceous. Dinosaurs roamed the ancient shorelines here both as individuals and in groups. Many footprints left by coastal sauropods have been preserved in the southwestern part of the state. The theropod "Arkansaurus fridayi" lived at this time, known only from remains of its foot. Since the preserved foot bones of Arkansaurus provide so little direct evidence about what the creature was like in life, much of what is known about "Arkansaurus" has to be inferred by analogy from other dinosaurs with similar anatomy.
Phanerozoic
The Mesozoic ranges from 252 million to 66 million years ago. Also known as "the Age of the dinosaurs", the Mesozoic features the rise of reptiles on their 150 million year conquest of the Earth on the land, in the seas, and in the air. There are three periods in the Mesozoic: Triassic, Jurassic, and Cretaceous.
Geomagnetic reversal
The "Cretaceous Normal" (also called the "Cretaceous Superchron" or C34) lasted for almost 40million years, from about , including stages of the Cretaceous period from the Aptian through the Santonian. The frequency of magnetic reversals steadily decreased prior to the period, reaching its low point (no reversals) during the period. Between the Cretaceous Normal and the present, the frequency has generally increased slowly.
Hauterivian
The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous epoch or a stage in the Lower Cretaceous series. It spans the time between 132.9 ± 2 Ma and 129.4 ± 1.5 Ma (million years ago). The Hauterivian is preceded by the Valanginian and succeeded by the Barremian.
Timeline of ceratosaur research
This timeline of ceratosaur research is a chronological listing of events in the history of paleontology focused on the ceratosaurs, a group of relatively primitive, often horned, predatory theropod dinosaurs that became the apex predators of the southern hemisphere during the Late Cretaceous. The nature and taxonomic composition of the Ceratosauria has been controversial since the group was first distinguished in the late . In 1884 Othniel Charles Marsh described the new genus and species "Ceratosaurus nasicornis" from the Late Jurassic Morrison Formation of the western United States. He felt that it belonged in a new family that he called the Ceratosauridae. He created the new taxon Ceratosauria to include both the Ceratosauridae and the ostrich-like ornithomimids. The idea of the Ceratosauria was soon contested, however. Later that same decade both Lydekker and Marsh's hated rival Edward Drinker Cope argued that the taxon was invalid.
Hațeg
Hațeg Island was an island during the Cretaceous Period where a dwarf species of sauropod dinosaur, "Magyarosaurus dacus", lived until their extinction at the end of the Cretaceous. Baron Franz Nopcsa published articles about these Mesozoic-era archosaurs on Hațeg Island. His studies led to his theory of insular dwarfism, the notion that "limited resources" on small islands can lead to a down-sizing of the indigenous vertebrate animals.
Cretaceous
Early Cretaceous
Alternatives to evolution by natural selection
Catastrophism has found a place in modern biology with the Cretaceous–Paleogene extinction event at the end of the Cretaceous period, as proposed in a paper by 
Walter and Luis Alvarez in 1980. It argued that a asteroid struck Earth 66 million years ago at the end of the Cretaceous period. The event, whatever it was, made about 70% of all species extinct, including the dinosaurs, leaving behind the Cretaceous–Paleogene boundary. In 1990, a candidate crater marking the impact was identified at Chicxulub in the Yucatán Peninsula of Mexico.
Crete
Hominids settled in Crete at least 130,000 years ago. In the later Neolithic and Bronze Age periods, under the Minoans, Crete had a highly developed, literate civilisation. It has been ruled by various ancient Greek entities, the Roman Empire, the Byzantine Empire, the Emirate of Crete, the Republic of Venice and the Ottoman Empire. After a brief period of independence (1897–1913) under a provisional Cretan government, it joined the Kingdom of Greece. It was occupied by Nazi Germany during the Second World War.
The Age of Reptiles
Cretaceous