Exam Review Part 2 Mesozoic, Cenozoic

Exam Review Part 2 Mesozoic, Cenozoic

BE SURE YOU CAN KNOW THE GEOLOGIC TIME LINE AND BE ABLE TOW LIST SEVERAL ORGANISMS THAT LIVED IN EACH Cenozoic Mesozoic- Holocene Pleistocene Pliocene Miocene Oligocene Eocene Paleocene Cretaceous Jurassic Triassic YOUNGEST Paleozoic- Proterozoic Archean Hadean Permian Pennsylvanian Mississippian Devonian Silurian Ordovician Cambrian OLDEST

The Mesozoic Era Mesozoic means "middle life Also = The Age of Reptiles Mesozoic Era consists of three periods: Triassic - Oldest. Lasted about 51 million years Jurassic - Lasted about 55 million years Cretaceous - Youngest. Lasted about 80 million years

Pangea At the beginning of the Mesozoic, the continents were assembled into a supercontinent, Pangaea. Pangaea formed in the Late Paleozoic = a single landmass surrounded by a vast ocean.

The Breakup of Pangea Pangaea began to break up in the Mesozoic. It broke in 4 stages

The Mesozoic Era is the "Age of Reptiles". Dinosaurs appeared in the Triassic Period, At the beginning of the Mesozoic Era, diversity was low following the Permian extinctions. However, by the late Triassic, the seas had abundant invertebrates

Triassic During the Triassic reptiles flourished New groups appeared = crocodiles, turtles Placodonts, Plesiosaurs, Ichthyosaurs, Nothosaurs,, Mammal-like reptiles survived from the Permian period. Early dinosaurs appeared by the middle of the Triassic period, and the first true mammals, small and rodent like had evolved by the end of the period. Plants = ferns, cycads, and seed-ferns all flourished. In the seas the first Hexacoral appeared, along with the first Belemnites. The Ammonites became more abundant

Dinosaurs The name "dinosaur" comes from the Greek deinos = "terrifying" and sauros = "lizard". Dinosaurs appeared in the Late Triassic, about 225 m.y. ago. The earliest dinosaurs were small. Many were less than 3 ft long. By the end of the Triassic, dinosaurs were up to 20 feet long. They became much larger later in the Jurassic and Cretaceous.

Hexacoral

Archosaurs Appear

'ruling lizards'

Turtle Relatives? Placodonts

Plesiosaur limbs that looked like paddles They appeared at the Triassic/Jurassic boundary

Conodonts- Eel like they were known only from toothlike microfossils

Belemnites

Triassic Mammal-Like Reptiles Mammals first appeared in the Triassic, Early mammals were small and rodent-like.

Reptiles were able to fly by gliding in the Triassic, and to fly with flapping wings by the Jurassic.

Primitive Triassic Fishes The fishes that existed during the Triassic had the following primitive characteristics: Diamond-shaped scales Skeletons partly cartilaginous Simple primitive jaws Asymmetrical tails Diamond-shaped scales of a Triassic freshwater fish

Triassic Plants- Cycads

Seed Ferns

Petrified Forest Petrified Forest National Park in Arizona has fossilized logs of trees in the Triassic The rocks of the Painted Desert in Arizona are also from the Triassic

Late Triassic Extinction Mass extinction occurred in the Late Triassic-as Pangaea began to break apart Affected life on the land and in the sea About 20% of all marine animal families extinct Conodonts (eels) and placodonts (marine reptiles-like turtles) extinct Bivalves, ammonoids, plesiosaurs, and ichthyosaurs affected but recovered and rediversified in the Jurassic. Among the terrestrial organisms affected by the extinction were mammal-like reptiles" and large amphibians.

Triassic Paleogeography Water covered part of the continent

The Diversity of Life in the Mesozoic Extinctions occurred in the Late Triassic and Late Cretaceous

Jurassic On the land dinosaurs thrive and grow large towards the end of the Jurassic period. The largest of these dinosaurs were the Sauropods, = Diplodocus and Brachiosaurus Later = specialized forms of plated dinosaur appeared, =Stegosaurus The first bird = Archaeopteryx, Mammal-like reptiles become extinct during this period. Plants = ferns, cycads, tree ferns and towering conifers. In the seas marine reptiles such as Ichthyosaurs and Plesiosaurs become common Ammonites,Belemnites., and Bivalves become abundant Sponges, Crinoids, Echinoids are also common, and Crustaceans such as the first crabs make their appearance. Brachiopods begin to decline

Jurassic Ichthyosaurs Become Abundant Ichthyosaur means 'fish-lizard' More advanced ichthyosaurs resemble modern dolphins and tuna

Teleost Fish the ray-finned fishes By the close of the Cretaceous, teleost fish had become the dominant fish Round scales Symmetrical tails 18-20 feet long

Belemnites Belemnites have shell that resembles a cigar rostrum. The belemnites were highly successful during the Jurassic and Cretaceous.

Dinosaurs Two Orders of dinosaurs are distinguished on basis of hip or pelvic structure: - lizard-hipped - bird-hipped bird-hipped lizard-hipped

Lizard-Hipped Dinosaurs Two groups: 1. Theropods - bipedal carnivorous dinosaurs 2. Sauropods - large quadrupedal herbivorous dinosaurs

Sauropods Large 4-legged herbivorous dinosaurs - long necks Apatosaurus Brachiosaurus Supersaurus Ultrasaurus Seismosaurus Argentinosaurus Nuoerosaurus Diplodocus

Examples: Ceratops Stegosaurs Ankylosaurs Ornithopods Bird-Hipped Dinosaurs

Ornithopods Bipedal and quadrupedal herbivores

The earliest true bird is Archaeopteryx, which appeared in the Jurassic Period.

MOSASAURS - LAST OF THE GREAT MARINE REPTILES

Rudists

Gastropods Predatory gastropods appeared in the Cretaceous. They were able to drill circular holes in shells in order to extract the soft parts of the organism for food. This was a new mode of predation not seen before. A common living example of a carnivorous gastropod is the moon snail.

Ammonites Ammonites = dominant swimming invertebrates in Mesozoic seas. were so abundant and varied that the Mesozoic could be called the "Age of Ammonites".

Cycads

Conifers

Jurassic Paleogeography

Cretaceous Giant Sauropod dinosaurs continue to survive although rare in some regions. Some plated dinosaurs, barely survive from the Jurassic period, Armored dinosaurs, (armor plates and spines,) and horned dinosaurs, such as Triceratops both flourish. The largest know land dwelling carnivore, the Tyrannosaurus rules Amphibians = frogs and salamanders. Lizards become common, including the giant Mosasaurs. Also in the seas = turtles are to be found, Archelon. Plesiosaurs continue to prosper, but Ichthyosaurs decline early in the Cretaceous period. Sponges, Bivalves and Echinoids are abundant, while Ammonites and Belemnites both begin to decline in numbers. Crustaceans such as lobsters become common. Modern teleost fishes become widespread towards the end of the period, and modern sharks appear during this time. Rays and skates were also present in the Cretaceous seas. Flowering plants, or Angiosperms, first appear.

Archelon

Cephalopods(Squids) Increase

Teleost Fish the ray-finned fishes By the close of the Cretaceous, teleost fish had become the dominant fishes in both the oceans and in freshwater habitats. 18-20 feet long

Gastropods Predatory gastropods appeared in the Cretaceous. They were able to drill circular holes in shells in order to extract the soft parts of the organism for food. This was a new mode of predation not seen before. A common living example of a carnivorous gastropod is the moon snail.

Late Cretaceous Extinction The Mesozoic Era ended with a major extinction. Affected both vertebrates and invertebrates, on land and in the sea. Extinction of dinosaurs, ammonites, large marine reptiles (Plesiosaurs, Ichthyosaurs, Mosasaurs), rudists, and others. Drastic reductions in, phytoplankton and belemnites.

Rocky Mountains The Rocky Mountains formed in New Mexico, Colorado, and Wyoming. Gold - The 1849 California gold rush was due to gold in gravels that is derived from gold-bearing quartz veins in the Sierra Nevadas Copper, silver and zinc - These minerals are found in the Butte, Montana and, Idaho mining districts and were due to Cretaceous igneous activity. Some copper deposits in the western U.S. are present in igneous rocks

Non-metallic Minerals Diamonds are found in Mesozoic igneous rocks in Siberia and Africa. Salt and sulfur are obtained from salt domes in the Gulf of Mexico area. Fossil fuels are derived from the partially decomposed remains of ancient organisms in sedimentary rock.

Oil And Natural Gas The largest oil and gas deposits in the world, in the Middle East and North Africa, come from Jurassic and Cretaceous sedimentary rocks Mesozoic oil and gas is also present in the western U.S., Alaska and Arctic Canada, the Gulf of Mexico region, Venezuela, Southeast Asia, North Sea, and offshore eastern Australia.

Cretaceous Paleogeography

Differences between some organisms

Pterodactyl (Flying Lizard) Skin Flap for wings- Point on head Archaeopteryx Feathers = True bird

Diplodocus A row of spines down its back A type of sauropod

More fossils of Diplodocus have been found than of just about any other sauropod, making this huge herbivore one of the most well-understood dinosaurs.

Brachiosaurus Knot on head

Dimetrodon=sail-backed

Ankylosaurs

The Cenozoic Era Name "Cenozoic" = "new life" or "recent life Cenozoic is known as the Age of Mammals" Dinosaurs and many other groups of reptiles from the earlier Cretaceous period are now all extinct. On land the mammals which survived from the Cretaceous period begin to expand rapidly.

BE SURE YOU CAN KNOW THE GEOLOGIC TIME LINE AND BE ABLE TOW LIST SEVERAL ORGANISMS THAT LIVED IN EACH Cenozoic YOUNGEST Holocene Rise of Modern Man, Modern animals Pleistocene- Wooly mammoths and Rhinoceroses and other giants go extinct at the end (Ice Age) Pliocene Sheep, Goats, Giant Ground Sloth, Primates Miocene Deer, Giraffe, Saber-tooth tigers, Giant Sharks, Coral & gastropod abundant Oligocene Dogs, Cats, Giant pigs, Camels, Armadillos, Ants and termites Eocene - Rodents abundant, Small horses, Insects important, Whales Paleocene- Flightless birds, Bivalves & gastropods Abundant (ammonites extinct) Sharks, Flowering plants

Bivalves and Gastropods replace the extinct Ammonites as the dominant mollusks. Sharks and teleost fishes are abundant. Flowering plants, or Angiosperms, become widespread. Insects become important for the pollination of flowering plants, or Angiosperms.

The climatic cooling near the end of the Cretaceous may have contributed to the extinctions of plants and animals at the end of the Mesozoic Era.

The Cenozoic Era followed the extinction of the dinosaurs and many other organisms The Cenozoic is the time of: (EVENTS) Development of the mammals Cooling of the Earth's climate resulting in the Ice Ages Appearance of humans

Major Events During the Cenozoic, the Atlantic and Indian Oceans widened, and the continents moved to their current positions. Half of the present ocean crust has formed at the mid-ocean ridges since the beginning of the Cenozoic.

Volcanoes of the Cascade Range Mt. St. Helens Mt. Rainier Mt. Adams Mt. Hood Mt. Jefferson Mt. Lassen Mt. Shasta

Mt. Rainier Mt. Rainier is considered to be the most dangerous volcano in the range. Major eruption about 2000 years ago, and minor eruptions in 1800's.

Active volcanism in many areas New Mexico, Arizona, Idaho,Texas Mexico Iceland Pacific rim Crustal uplift in many areas Tetons of Wyoming Sierra Nevada central and northern Rockies Alps Himalayas

Later Cenozoic = the Ice Ages when extensive ice sheets spread towards the equator from both the Antarctic and Arctic regions covering much of Europe and North America. The last of these ice sheets disappeared about 10,000 years ago. The extinction of many species of mammals, particularly giant forms. Sabre-toothed cats, cave lions, cave bears, giant deer, woolly rhinoceroses, and woolly mammoths are extinct.

The Little Ice Age Cold spells recurred periodically The Little Ice Age lasted from 1540 1890. Temperatures were several degrees cooler than today. Loss of harvests, famine, food riots, and warfare in Europe. Cold conditions correlate with periods of low sunspot activity. A time of extremely low sunspot activity from 1645-1715 is known as the Maunder Minimum.

The Little Ice Age cont d Heightened volcanic activity occurred during the Little Ice Age. Volcanic ash and aerosols in the atmosphere caused temperatures to drop by blocking out incoming solar radiation. The eruption of Mount Tambora in Indonesia in 1815 was followed by the Year Without A Summer. Frost and snow were reported during June and July of 1816 in New England and Northern Europe.

End of the Little Ice Age Human-induced warming may be the reason for the end of the Little Ice Age. Greenhouse gases associated with the Industrial Revolution are the major factors influencing global warming and climate change today.

We know more about the life of the Cenozoic Era than we know about life of any other time. This is because the fossils are better preserved and have had less time to be destroyed, they are in the uppermost rock layers, and more accessible for study. In addition, Cenozoic fossils more closely resemble life today.

Saber Tooth Tigers

GIANT BEAVER Largest rodents to have ever lived! About the size of a modern Black Bear, it was 6-8 ft. (2.5M) in length, about 3.3 ft. (1M) in height, and weighing in at 450-500 lbs. (218

Wooly Mammoth

Difference Mastodon Mammoth Straighter tusk / 6-9 feet at shoulder Curved Tusk /12 feet at shoulder

Huge Ground Sloth

Extinction of the Large Mammals Most of these large land mammals began to become extinct around 8000 years ago. Why? There are two hypotheses: Human hunting and predation Climate change associated with global warming at the end of the last Ice Age.

The End- Good luck on the exam Don t forget how awesome the Earth really is