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History/Origins/Future
of Energy, Matter, Space, Time, and Life (4 of 7) ~~~~~~~~~~~~~~~~~~~ From ~145 Million Years Ago to ~23 Million Years Ago ~~~~~~~~~~~~~~~~~~~ (updated August 16, 2009) Years Ago Event ------------------------------------------ ~145 million to ~65 million .... Cretaceous Period 145 Million to 65 Million Years Ago http://science.nationalgeographic.com/science/prehistoric-world/cretaceous.html "... At the start of the period, dinosaurs ruled the loosening remnants of the supercontinent Pangaea ... At the end of the period, about 80 million years later, oceans filled yawning gaps between isolated continents shaped much as they are today. Flowering plants were spreading across the land- scape. And mammals sat poised to fill the void that soon would be left by the vanished dinosaurs. A giant crater smoldered on what would become known as the Yucatán Peninsula. Whether or not the asteroid or comet that carved the Chicxulub crater caused the extinction of more than half the planet's species at the end of the Creta- ceous remains a matter of scientific debate. ... ... the Cretaceous picked up where the Jurassic left off: Gigantic sauropods led parades of dinosaurs through the forests, over the plains, and along the coasts; long-necked and toothy marine reptiles ter- rorized fish, ammonites, and mollusks in the seas; pterosaurs and hairy-feathered birds filled the skies.
But as the continents spread, the ocean currents churned with ever more vigor. After a temperature spike in the mid-Cretaceous, the climate began to cool ...
Though dinosaurs ruled throughout the Cretaceous, the dominant groups shifted and many new types evolved. Sauropods dominated the southern con- tinents but became rare in the north. Herd-dwelling ornithischians like Iguanodon spread everywhere but Antarctica. Toward the close of the Cretaceous, vast herds of horned beasts such as Triceratops munched cycads and other low-lying plants on the northern continents. The carnivore Tyrannosaurus rex dominated the late Cretaceous in the north while monstrous meat-eaters like Spinosaurus, which had a huge sail-like fin on its back, thrived in the south. 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. The largest pterosaur known soared overhead though the group as a whole faced ever stiffening competition from fast diversifying birds: Ancestors to modern grebes, cormorants, pelicans, and sandpipers all show up in the Cretaceous. In the warm, shallow seas that spilled onto the continents, the long-necked plesiosaurs gave way to the giant, snake- like mosasaurs. Rays and modern sharks became com- mon. Sea urchins and sea stars (starfish) thrived; coral reefs continued to grow. Diatoms, a type of shelled plank- ton, made their first radiation into the ocean. But it was the rapid dispersal of flowering plants that stole the show—a spread enhanced with the help of insects from bees and wasps to ants and beetles. Magnolia, ficus, and sassafras quickly outnumbered ferns, conifers, gingkoes, and cycads. Much of this rich life—including all dinosaurs, pterosaurs, pliosaurs, and ammonites—perished in the extinction event at the end of the period 65 million years ago. ... ~130 million to ~125 million .... Amargasaurus http://ngm.nationalgeographic.com/2007/12/bizarre-dinosaurs/dinosaur-photography "... X-FACTOR: Double row of spines on neck and back WHEN: 130-125 million years ago WHERE: Argentina Like the tail fins on a 1959 Cadillac, a bizarre double row of spines extending from the vertebrae of Amar- gasaurus may have served little purpose other than to turn heads. Since the discovery of the sauropod was announced in 1991, paleontologists have pondered the function of the delicate bony rods, which would have offered limited defense at best against predators."
~127 million .... Giants of the Skies - the Early Cretaceous Earth http://www.bbc.co.uk/sn/prehistoric_life/dinosaurs/chronology/127mya1.shtml Walking With Dinosaurs -- Giants of the Sky http://en.wikipedia.org/wiki/Walking_With_Dinosaqrs#.22Giant_of_the_Skies.22 "... 127 million years ago — Early Cretaceous — Young Atlantic Ocean Filming locations: New Zealand, Tasmania Conditions: Sea and coastlands. [featured in this episode]
Plants with flowers evolve; dinosaurs evolving in this period (Cretaceous) include Iguanodon, Tyrannosaurus rex, Diplodocus, Triceratops, Protoceratops, Hypsilophodon, Polocanthus, Baryonyx, Styracosaurus, Brachyceratops, Centrosaurus, Chasmosaurus, Gallimimus, Saltasaurus, Alamosaurus, Corythosaurus, Ankylosaurus. ~110 million year old dinosaur, the largest ever discovered; weighed 60 tonnes and stood 18 metres (60 feet) tall - Sauroposeidon: http://news.bbc.co.uk/hi/english/sci/tech/newsid_503000/503682.stm ~106 million .... Spirits of the Ice Forest - Dinosaurs at the Poles http://www.bbc.co.uk/sn/prehistoric_life/dinosaurs/chronology/106mya1.shtml Walking With Dinosaurs -- Spirits of the Ice Forest http://en.wikipedia.org/wiki/Walking_With_Dinosaurs#.22Spirits_of_the_Ice_Forest.22 "... 106 million years ago — Mid Cretaceous, in the rift valley where Australia is beginning to separate from Antarctica. Conditions: Forest dominated by podocarps, very near South Pole (the sun did not rise for 5 months in the winter). The lopsided arrangement of the continents keeps ocean currents and strong monsoon winds blowing across the polar area, keeping it free of icecap and warm enough for forests to grow. Filming location: New Zealand [featured in this episode]
~100 million .... Marsupials (including kangaroos, koalas, and opossums) evolve; insectivores (the first placental mammals) evolve; almost all are small and nocturnal or crepuscular (active at dusk or dawn). ~100 million year old dinosaur, the largest meat ever discovered (45 feet long), on the eastern slopes of the Argentinian Andes: http://news.bbc.co.uk/hi/english/sci/tech/newsid_675000/675939.stm Click-drag virtual reality display of continental drift in the Caribbean Sea, with Cuba moving from south of Mexico to its current position from ~100 million years ago to the present day: http://www.scotese.com/caribanim.htm ~94 million .... View of the earth in the late Cretaceous: http://www.scotese.com/cretaceo.htm ~90 million .... Click-drag virtual reality display of continental drift resulting in the merger of India with Asia from ~90 million years ago to the present day: http://www.scotese.com/indianim.htm ~82 million to ~67 million .... Carnotaurus http://ngm.nationalgeographic.com/2007/12/bizarre-dinosaurs/dinosaur-photography "... X-FACTOR: Bull horns, tiny arms WHEN: 82-67 million years ago WHERE: Argentina Consider the evolutionary hand dealt to Carnotaurus, or 'meat-eating bull': a big, bad, but seemingly under- equipped predator, as if nature had set out to design a perfect killing machine but ran out of funding. Powerful jaws and long, agile legs suggest a highly mobile hunter prowling the lakeshores of what is now Patagonia. "
~80 million .... Scientists have unearthed a remarkable dinosaur nesting ground strewn with thousands of ~80 million year old fossilised eggs, in Argentina: http://news.bbc.co.uk/hi/english/sci/tech/newsid_216000/216105.stm ~70 million to ~65 million .... Masiakasaurus http://ngm.nationalgeographic.com/2007/12/bizarre-dinosaurs/dinosaur-photography "... X-FACTOR: Inscrutable teeth WHEN: 70-65 million years ago WHERE: Madagascar The mouth of Masiakasaurus speaks to how this German shepherd-size meat-eater survived in the river basins of northwestern Madagascar, near the end of the dinosaurs’ reign. But what is it saying?"
~66 million .... ~66 million year old dinosaur heart discovered: http://news.bbc.co.uk/hi/english/sci/tech/newsid_720000/720871.stm View of the earth at the K/T boundary: http://www.scotese.com/K/t.htm ~65 million to ~23 million .... Paleogene Period 65 Million to 23 Million Years Ago http://science.nationalgeographic.com/science/prehistoric-world/paleogene.html "... At the dawn of the Paleogene—the beginning of the Cenozoic era—dinosaurs, pterosaurs, and giant marine reptiles were conspicuously absent from the face of the Earth. Rodent-size (and perhaps larger) mammals emerged from the shadow of the night, suddenly free to fill the void. Over the next 42 million years, they grew in size, number, and diversity. As the period came to a close, life-forms still common today filled the seas, dominated the land, and had taken to the air. During the Paleogene the continents drifted farther apart, heading toward their modern positions. Oceans widened the gaps, Europe severed its last ties with North America, and Australia and Antarctica finally parted ways. As the climate significantly cooled and dried, sea levels continued to drop from late Creta- ceous levels, draining most interior seaways. ... the biggest development in the seas was the appear- ance of whales in the mid- to late Paleogene. The huge animals evolved from land mammals that took to the seas. Meanwhile, smaller reptiles that survived the Creta- ceous, such as turtles, snakes, crocodiles, and lizards, basked in the tropical warmth along the coasts. Birds, the holdouts of the dinosaur age, diversified and flour- ished in the skies. But the rapidly evolving mammals stole the show. Starting from a fairly humble position 65 million years ago, primates, horses, bats, pigs, cats, and dogs had all evolved by the close of the period, 23 million years ago. What Killed the Dinosaurs? http://science.nationalgeographic.com/science/prehistoric-world/dinosaur-extinction.html Asteroid impacts discussed, with details on the likelihood the Chicxulub impact was the cause of the Cretaceous mass extinction event as well as the theory that since the antipodal point for the impact (i.e., the opposite side of the earth at the time of the impact) was India, the impact was the cause of the Deccan Traps flood basalt lava flows: http://www.space.com/scienceastronomy/astronomy/asteroid_paine_october.html K/T impact Chicxulub Crater, Yucatan Peninsula, 124-186 miles wide: http://www.agu.org/sci_soc/sharpton.html Dinosaurs were not going extinct before they were wiped out: http://news.bbc.co.uk/hi/english/sci/tech/newsid%5F863000/863320.stm Were dinosaurs done in by gas? http://www.msnbc.msn.com/id/30833535/ "... When a giant asteroid slammed into the Yucatan Peninsula 65 million years ago, the results were devas- tating: rock and ocean water vaporized, searing debris flung into outer space, and a smoldering hole in the Earth almost 75 miles wide. Scientists debate whether the cataclysm was enough to wipe out the dinosaurs. But a new set of experi- ments shows the impact produced a huge amount of carbon monoxide, a compound commonly found in car exhaust. The sudden pulse of gas may have been enough to cause a large spike in global temperatures, and trigger a mass extinction. ..." More than 170 Humongous Holes Scientists still counting impacts found across all continents and sea floor http://www.msnbc.msn.com/id/24110485/ "... At last count, there were more than 170 known mpact craters on our planet, according to the Earth Impact Database maintained by the University of New Brunswick in Canada. These puncture wounds are littered over every continent, as well as the seafloor. There would be countless more if it weren't for Earth's constant remodeling. Plates shift, mountains form, vol- canoes erupt and erosion washes over the planet's sur- face, continually hiding the evidence of most craters. ... One of Earth's most recently-formed holes is Ari- zona's Barringer Meteor Crater, created around 50,000 years ago. Though this crater, one of the most famous, awes tourists with its roughly three- quarters of a mile diameter, it is considered quite dinky on the geological scale. ... A major heavyweight is South Africa's Vredefort crater, which at 186 miles wide, is said to be Earth's largest verified impact crater. At more than 2 billion years old, it is also one of the most ancient. Other contenders are the 155 mile-wide Sudbury Basin in Ontario, Canada, and the roughly 110 mile- wide Chicxulub crater, half submerged off the coast of the Yucatán Peninsula in Mexico. ... If it weren't for erosion and other geological pro- cesses that erase evidence of craters, there would likely be hundreds of thousands of impact craters on the Earth ..." Volcanoes could have caused dinosaur deaths http://www.msnbc.msn.com/id/21755313/?GT1=10547 Death of a Dynasty - The End of the Cretaceaous http://www.bbc.co.uk/sn/prehistoric_life/dinosaurs/chronology/65mya1.shtml Walking With Dinosaurs -- Death of a Dynasty http://en.wikipedia.org/wiki/Walking_With_Dinosaurs#.22Death_of_a_Dynasty.22 "... 65 million years ago — Late Cretaceous — Montana Conditions: Areas of low herbaceous plant cover, and forest, affected by volcanism. The episode shows some effects of volcanic activity Filming location: Chile (Conguillío National Park) [featured in this episode]
Earliest-known rodents evolve, resembling small squirrels - rodents are the largest order of mammals in the present day, by far, with about 2,000 species in 35 families; first armadillos evolve; creodonts, the dominant flesh-eating mammals for 30 million years, appear on the scene. ~55 million .... Mammals begin to thrive; earliest lagomorph (ancestor to pikas, rabbits, hares) evolves. ~50 million .... Fossil record shows a diversification of ancestral primates resulting in around 6,000 species of the subsequent millennia, of which there are about 200 species alive today. Bear-dogs, a varied and successful group of hunting animals, originate and spread through Europe and North America. View of the earth in the middle Eocene: http://www.scotese.com/newpage9.htm ~49 million .... Walking With Beasts -- New Dawn http://en.wikipedia.org/wiki/Walking_With_Beasts#.22New_Dawn.22 "... Film location: Java 49,000,000 years ago — Early Eocene — Germany [featured in this episode]
~47 million .... Ida, 'Missing Link' in Human Family Tree? http://prohuman.net/science/ida_missinglink_humanfamilytree.htm ~45 million .... First anteaters evolve. Shallow seas retreat in North America; continents appear fairly modern in form; quite a large sea area still separates Africa from Europe and Asia; India is now north of the equator on its journey towards its eventual landfall in Asia. ~40 million .... Life thrives and expands in cold but nutrient- rich Antarctic bottom waters; toothed whales' land-roving mammalian ancestors return to the sea; canids (including the modern foxes, jackals, coyotes, wolves, and dogs) originate at this time; camels make their debut. ~36 million .... Walking With Beasts -- Whale Killer http://en.wikipedia.org/wiki/Walking_With_Beasts#.22Whale_Killer.22 "... Filming Location: Florida 36,000,000 years ago — Late Eocene — Pakistan - Egypt [featured in this episode]
~35 million .... Beavers evolve - the early beaver was small and lived on and near freshwater lakes; creodonts evolve to a large size in Mongolia with one of the largest, Sarkastodon, bigger than the biggest bear; modern raccoons and pandas first appear; earliest cats evolve; rhinoceroses evolve; deerlike animals evolve. ~33 million .... New world monkeys evolve in South America (Bolivia). ~30 million .... Grassland and trees with fruits spread; mammals help pollinate and fertilize as they graze and swallow fruits; earth grows cooler and extinction overtakes animals requiring steamy climates; seals first appear; pigs make their debut. ~25 million .... Onset of Antarctic ice shelf. Walking With Beasts -- Land of Giants http://en.wikipedia.org/wiki/Walking_With_Beasts#.22Land_of_Giants.22 "... Filming Location: Mexico and Arizona (Grand Canyon) 25,000,000 years ago — Late Oligocene — Mongolia [featured in this episode]
Ancestors of modern apes appear. --- end 4 of 7 --- |
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