You are currently browsing the tag archive for the ‘Permian’ tag.

The Snider-Pellegrini-Wegener fossil map which illustrates how scientists pieced Pangaea together

The Snider-Pellegrini-Wegener fossil map which illustrates how scientists pieced Pangaea together

During the Permian era (around 300 million years ago) the strange slow dance of Earth’s tectonic plates brought together all the world’s major landmasses into the supercontinent Pangaea.  Because of its very nature, Pangaea changed the world’s climate in bizarre ways.  Baking hot deserts were so far from the coast that they never received rain.  Landlocked seas boiled away and left great evaporitic deposits of strange minerals which we still mine and exploit.  Huge mountains rose and fell as the continents crashed together.

Pangaea lasted for approximately 100 million years, during a time of tremendous biological upheaval and diversification.  The worst mass extinction in the history of life took place during the continent’s heyday (The Permian-Triassic extinction event took place about 250 million years ago).  After the great dying, he first dinosaurs and mammals walked the super continent.  However this post is not a meditation concerning Pangaea (thankfully– since its history is extraordinarily complicated).

Triassic Pangaea by Richard Morden

Triassic Pangaea by Richard Morden

The idea which excites me is that Pangaea was only a third of the Earth.  The remainder of the globe was taken up by water.  Between Laurasia and Gondwana there was a great wedge shaped ocean called the Tethys Ocean (indeed Pangaea looked somewhat like Pacman—as you can see on the beautifully illustrated map by Australian freelance illustrator Richard Morden).  Named after a titaness who was the daughter of Uranus and Gaia, the Tethys radically changed shape as the continents separated.  Through big parts of its history, large parts of the Tethys consisted of warm shallow continental shelves (which are ideal environments for fossil deposits).  Paleontologists and Geologists thus know a great deal about the natural history of the Tethys Ocean.

panthlogo

The remainder of the globe was a single world ocean called Panthalassa (or the Panthalassic Ocean).  If you looked at Earth from outer space from a particular angle it would have been entirely blue (which is fitting for “Panthalassa” was not named after any god or goddess but from a Greek neologism meaning “universal sea”).  The Panthalassa is not so well known as the Tethys.  As Pangaea broke apart almost the entire ocean floor was subducted underneath the North American and Eurasian plates.  However Geologists sometimes find tiny distorted remnants which were one part of the gigantic world sea.

PacificOcean

Conifers are amazing! Also happy holidays from Ferrebeekeeper.

It is the holiday season and decorated conifers are everywhere. Seeing all of the dressed-up firs and spruces reminds me that Ferrebeekeeper’s tree category has so far betrayed a distinct bias towards angiosperms (flowering plants). Yet the conifers vastly outdate all flowering trees by a vast span of time.  The first conifers we have found date to the late Carboniferous period (about 300 million years ago) whereas the first fossils of angiosperms appear in the Cretaceous (about 125 million years ago) although the flowering plants probably originated earlier in the Mesozoic.

The first known conifer trees resembled modern Araucaria trees.  They evolved from a (now long-extinct) ancestral gymnosperm tree which could only live in warm swampy conditions—a watery habitat necessitated since these progenitor trees did not cope well with dry conditions and also probably utilized motile sperm.  Instead of relying on free-swimming gametes and huge seeds, the newly evolved conifers used wind to carry clouds of pollen through the air and were capable of producing many tiny seeds which could survive drying out.  Because the evergreen cone-bearing trees could survive in drier conditions, the early conifers had immense competitive advantages.  These advantages were critical to survival as the great warm swamps of the Carboniferous dried out.  The continents, which had been separated by shallow oceans and seas, annealed together into the baking dry supercontinent of Permian Pangaea.  In the arid deserts and mountains, the conifers were among the only plants which could survive.

Pay attention to the Trees in this Painting not the Dinosaurs (art by Jon Taylor)

This ability to live through any condition helped the conifers get through the greatest mass extinction in life’s history—The Permian–Triassic (P–Tr) extinction event, (known to paleontologists as “the Great Dying”).  Thereafter, throughout the Mesozoic they were the dominant land plants (along with cycads and ginkgos which had evolved at about the same time).  The Mesozoic saw the greatest diversity of conifers ever—the age of dinosaurs could just as well be called the age of conifers.  Huge heard of sauropods grazed on vast swaths of exotic conifers. Beneath these strange sprawling forests, the carnosaurs hunted, the early birds glided through endless green canyons, and the desperate little mammals darted out to grab and hoard the pine nuts of the time.

The Great Boreal Forests of Canada (photo by Chad Delany)

Although flowering plants rapidly came to prominence towards the end of the Cretaceous and have since become the most diverse plants, today’s conifers are not in any way anachronisms or primitive also-rans.  They still out-compete the flowering trees in cold areas and in dry areas. Conifers entirely dominate the boreal forests of Asia, Europe, and North America—arguably the largest continuous ecosystem on the planet except for the pelagic ocean.  They form entire strange ecosystems in the Araucaria moist forests of South America—which are relics of the great conifer forests of Antarctica (the southern continent was once a warmer happier place before tectonics and climate shift gradually dragged its inhabitants to frozen death).

Contemporary Araucaria Forest in South America (photo by Garth Lenz)

The largest trees—the sequoias and redwoods–are conifers.  The oldest trees—bristlecone pine trees and clonal Spruces–are conifers (excepting of course the clonal colonies).  Conifers are probably the most commercially important trees since they are fast-growing staples of the pulp and the timber industries. Timber companies sometimes buy up hardwood forests, clear cut the valuable native deciduous trees and plant fast growing pines in their place to harvest for pulp.  In fact all of the Christmas trees which are everywhere around New York come from a similar farming process.  The conifers are nearly everywhere—they have one of the greatest success stories in the history of life.  It is no wonder they are the symbol of life surviving through the winter to come back stronger.  They have done that time and time again through the darkest and driest winters of the eons.

A Grove of Giant Sequoias (Sequoiadendron giganteum)

Ye Olde Ferrebeekeeper Archives

October 2020
M T W T F S S
 1234
567891011
12131415161718
19202122232425
262728293031