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“April showers bring May flowers.” So April’s been getting the credit all these years. Or maybe, just maybe, it was the dinosaurs!
The Dinosaur Herbivores
There are basically two kinds of plants, gymnosperms and angiosperms. All flowers – including May flowers - are angiosperms, and so are grains, grasses, cereals, sedges, fruits, vegetables, palms, oaks, hickories, almost every berry, etc. Today angiosperms dominate the planet. However, once upon a time, gymnosperms - like conifers and ferns - were king.
Then 140 million years ago, everything started to change. During the Jurassic, all the major herbivores were long-necked, tree-browsing dinosaurs (Brontosaurus, Brachiosaurus, Diplodocus, etc.). By the Cretaceous, almost all of those tree-browsers were extinct. In the Cretaceous, the major herbivores were low-browsing ground-feeders.
The Dino-Flower Theory
Robert T. Bakker in his famous book The Dinosaur Heresies postulated that this new dominant ground-browsing herbivore created an flower-favorable environment. A gymnosperm-dominated woodland would provide few available niches for early flowering plants to occupy. But if a herd of hungry Triceratops mowed down the ground cover, the net effect would reset all the ground cover back to square one. Ground cover would have to grow from scratch, similar to after a forest fire. Angiosperms with their faster growth and maturity rates would recover first and dominate the newly available niches. Flowering plants flourished. May flowers rule!
But Bakker has his critics too. For example, angiosperms first flourished close to the equator. Dinosaurs only sparsely populated this region, which would seem to diminish the effect of their appetites. Furthermore, angiosperms didn’t dominate the plant world until the Late Cretaceous, when dinosaur numbers already were starting to dwindle. Others believe that environmental factors may have aided angiosperms more than dinosaur herbivores. The Mid-Cretaceous was a period of increased volcanism and ocean floor production. Did increased temperature, CO2, and sea levels favor angiosperms over gymnosperms? Or did the rise of the pollinator insects (wasps, bees, and moths) during the Mid-Cretaceous give angiosperms their decisive advantage?
In any case, the world the dinosaurs left behind was angiosperm-supreme. The graves of dinosaurs were festooned with flowers.
Bakker, Robert T. The Dinosaur Heresies: New Theories Unlocking the Mystery of the Dinosaurs and their Extinction. New York: William Morrow, 1986.
Barrett, P.M. and Willis, K.J. Did dinosaurs invent flowers? Dinosaur-angiosperm coevolution revisited. Biological Reviews of the Cambridge Philosophical Society 76 (2001), 411-447.
Willis, K.J. and McElwain, J.C. The Evolution of Plants. New York: Oxford UP, 2002
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Diamonds are forever? But historically speaking, emeralds are the most prestigious gems.
In ancient history, Egypt was the only major source for emeralds. According to legend, Cleopatra once greeted Caesar from atop a pile of emeralds. Egyptian emeralds and gold funded Roman coffers. In the sixth century Emperor Justinian decreed that only aristocracy could wear emeralds. Napoleon favored emeralds because of its connection to ancient imperial power.
Why does history favor emeralds over diamonds? Diamonds require facets for their brilliance, and faceting technology wasn’t developed until the late 15th century. Before the art of faceting, diamonds were secondary, emeralds were king!
Emeralds don’t need complex faceting. Emeralds don’t sparkle – they shine! They look wet. That’s why emeralds are usually made with a “table cut” – a long flat surface – instead of with many facets.
The emerald’s crystal structure creates that natural luster. Emeralds naturally have a long hexagonal crystal. The crystal shape is due to the fact that an emerald is a beryl mineral (beryllium aluminum cyclosilicate).
Pure beryls are naturally white and called goshenite. But when the beryl contains chromium, then the beryl turns green. An emerald is born! Incidentally, aquamarine is a beryl too – or if you rather – just an emerald with an iron contamination.
That chromium combines with beryllium at all is a freak occurrence in nature. Chromium occurs on the ocean floor. Beryls are born in the granite hearts of mountains. When two continents collide, the ocean floor is pushed under a continent (subduction). When the ocean rock melts, the chromium mixes into the rising fluid and finds its way into the growing beryl crystals.
Author and jeweler Aja Raden writes that beryllium and chromium are “the Romeo and Juliet of elements” because under “no normal circumstances should these rare substances ever find each other.” Raden’s book "Stoned" is a must-read for gem enthusiasts and history buffs.
Emeralds are filled with inclusions, which are the stone's jardin – or garden. Using a 10x loupe, the inclusions look like a jungle or coral reef. Each jardin can be as unique as a snowflake.
But beware! Often, emeralds are treated with oils and fillers. That’s why you should never wash your emeralds in an ultrasonic cleaner.
Today Colombia dominates emerald production. Scattered lesser sources for emeralds exist, even in the United States. In fact, North America’s largest emerald was discovered in North Carolina in 2009. Starting at an impressive 310 carats, it was cut down to about 65 carats and named “The Carolina Emperor.”
The Green Envy
Cone cells in the human eye see red, blue and green. But all cone cells are sensitive to light wavelengths of 510 nanometers, i.e. the eye is most receptive to green! It’s the color of life, especially as life renews in spring. Appropriately, May’s birthstone is the emerald. Emeralds are prestigious, but spring…that’s priceless.
Finlay, Victoria. Jewels: A Secret History. New York: Ballantine, 2006. Print.
Raden, Aja. Stoned: Jewelry, Obsession, and How Desire Shapes the World. New York: HarperCollins, 2015. Print
Gast, Phil. "North Carolina emerald: Big, green and very rare." CNN.com. 1 September 2010. Retrieved from http://www.cnn.com/2010/US/08/31/north.carolina.emerald/ (Accessed March 27, 2016)
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As summer looms ahead, the season of beaches begins! But enjoy it while you can. To a geologist, beaches are very temporary things.
Every modern beach in the world today did not exist twenty thousand years ago!
At the peak of the last Ice Age, sea level was at least 90 meters (300 feet) lower than it is today. Ice Age beaches would have been miles farther out to sea! Los Angeles, Sarasota, Myrtle Beach - any city famous for its fun in the sun - would have been landlocked completely. There was no such thing as an English Channel, a Bering Strait, or even the Great Lakes.
Going to the lake this summer? Modern lakes didn’t exist during the last Ice Age. Most lakes in the Midwest are “kettle lakes”, lakes created by great chunks of retreating glaciers that broke off and melted in place.
But the Ice Age did have some enormous lakes! They just don't exist anymore. A glacial dam in Montana would create the legendary Lake Missoula. Lake Missoula at its peak covered 2,000 square miles and contained over 500 cubic miles of water - half the volume of modern Lake Michigan!
Glacial Lake Wisconsin was born when the Green Bay Lobe (a glacial lobe over present-day Green Bay) created a dam on the Wisconsin River. Glacial Lake Wisconsin would eventually grow as large as the Great Salt Lake.
However, glacial dams are made of ice. Since ice has only nine-tenths of water’s density, rising water levels will create a buoyant force that tries to lift an ice dam, like how ice cubes float in your ice tea.
When that happens, glacial lakes will empty violently!
When the dam broke on Lake Missoula, over 500 cubic miles of water suddenly raced to the ocean! This created the eerie landscape known as the Channeled Scablands of the Columbia Plateau. When the southern moraine collapsed, the explosive draining of Glacial Lake Wisconsin carved out the Wisconsin Dells, which today are a major tourist attraction.
Some Ice Age lakes were created by climate changes. Lake Bonneville was a lake that covered over 20,000 square miles - almost as big as Lake Michigan - and stretched from Idaho through Utah. Lake Lahontan in Nevada’s Great Basin Range grew to cover 8,570 square miles (bigger than Lake Ontario’s 7,540 square miles). Both Bonneville and Lahontan were over 900 feet deep, deeper than any Great Lake except Lake Superior.
What created these monsters? It was Ice Age weather! The jet stream is a zone of high-velocity wind that carries moist air from the Pacific into the American Northwest and Canada. This wind pattern strongly influences the humid climate in coastal Washington and Oregon, making it quite different from the arid Southwest. But during the Ice Age, the fierce cold of the continental ice sheet split the jet stream and established a strong region of high pressure, called an anticyclone.
This anticyclone drove part of the jet stream north and the other part south – a deflection of as much as three degrees of latitude. This detour brought the moisture-laden jet stream into the arid Great Basin, which created huge pluvial lakes. But with the ice sheet’s retreat, precipitation decreased. Lakes Bonneville and Lahontan slowly shriveled up. The Great Salt Lake – and its little sister, Utah Lake – is all that remains of the mighty Lake Bonneville. Tiny Lake Walker in Nevada is all that remains of Lake Lahontan.
Beaches may come and go, but these processes take thousands of years.
Maybe it’s all relative. After all, doesn’t every summer go by in a blink too?
Alt, David. Glacial Lake Missoula and its Humongous Floods. Missoula, MT: Mountain, 2001.
Dott, Richard H., and John W. Attig. Roadside Geology of Wisconsin. Missoula, MT:Mountain, 2004.
Orndorff, Richard L., Robert W. Wieder, and Harry F. Filkorn. Geology Underfoot in Central Nevada. Missoula, MT: Mountain, 2001.
Orndorff, Richard L., Robert W. Wieder, and David G. Futey. Geology Underfoot in Southern Utah. Missoula, MT: Mountain, 2006.
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It’s morel mushroom season! But what if I told you that once upon a time, before the first dinosaur ever roared, there were mushrooms that were as big as palm trees!
I’m talking about Prototaxites, a super-fungus which was once the largest land creature on the planet.
Picture Earth during the late Silurian to late Devonian Period (i.e., 420 to 370 million years ago). This was long before the giant ferns and conifers that would father the coal fields of the world. Plants are small, timidly exploring this crazy place called “Dry Land.”
In this proto-forest of dwarf plants, Prototaxites could be a 1 meter (3 feet) thick and almost 8 meters (26 feet) high!
The Prototaxites were discovered first in Canada by W.E. Logan in 1843. But it was John William Dawson who would name the species fourteen years later. Dawson thought the tree was a kind of ancient pine tree (“first yew”, or Prototaxite) that had been eaten up by fungi.
The Fungus Theory
But a century and half later, plant scientist Francis Hueber classified Prototaxites – the whole thing - as one big fungus, due to its structure and morphology.
A few years later, a research team (including Hueber) concluded that Prototaxites was indeed a fungus, due to its variety of carbon isotopes. In plants, like today's trees, two particular carbon isotopes should be in balance because they get their food by photosynthesis. In plants and animals that eat other life-forms, the isotope ratio should vary widely. The Prototaxites’ combination of isotopes indicated that it fed on decaying organic matter, just what you would expect from a fungus.
Of course, if Prototaxites was a large fungus, it would also need a large food supply. But if the plant world was new and small, where would the food come from? Scientists Erik Hobbie and C. Kevin Boyce suggested that Prototaxites could have fed on “algal-derived organic matter.” Algal mats were most likely because there weren’t many true (vascular) plants for a good compost.
The Non-Fungus Theory
However, another group of researchers asserted that Prototaxites was more like a kind of liverwort, curling up with other liverworts and plants and ascending into the air. They thought that the fungus-like structure was just an associative growth with fungi and cyanobacteria, just like in some modern liverworts.
But the “monster mushroom” theory is currently in vogue.
The Mushroom Vogue
Did Jules Verne know about Prototaxites? In chapter 30 of Jules Verne’s classic “Journey to the Center of the Earth,” the heroes find themselves in “a forest of mushrooms” that had been “constructed on a gigantic scale.”
Simon and Schuster’s 2008 edition of the classic has a drawing of the mushroom forest on its cover. If you eliminated the mushroom caps, you’d get a pretty good visual of Prototaxites.
My cousin told me he was a “mushroom hunter.” I told him that you can’t call it “hunting” when the prey lacks teeth or even feet to run away. But who could hunt Prototaxites? Not even Mario and Luigi.
Hello! My name is Heath Shive, content manager at ScholarFox. I'll be the author of most of the blog posts. I'm a former geologist and currently a freelance writer. The world is complex and seemingly crazy. Good! Because when you love to learn, you'll never be bored.