palentology

THE THREE LAYER CAKE

There are thousands upon thousands of layers in the earth’s crust. However, scientists have grouped the layers into major groups. The most recent three layers are the Paleozoic, Mesozoic, and Cenozoic. These layers represent the last 500 million years of life on earth.

In the Paleozoic, you find fish, amphibian, and reptile fossils (in that order), but never dinosaurs, birds, modern mammals, or even flowering plants.

Think of that: despite the billions of plant fossils in the Paleozoic layer, nobody has ever found one fossil of a flower, including any kind of deciduous tree or even a single blade of grass. Why not? The obvious explaination is flowers had not evolved yet.

The next layer, the Mesozoic, is often called the age of dinosaurs. The Mesozoic has dinosaurs like crazy. Of course, dinosaurs are reptiles and that’s why you won’t find any until after the Paleozoic which contains the first reptiles. The Mesozoic also has the first flowering plants, birds, and mammals, though few if any birds or mammals that we know of today.

On top of the Paleozoic and Mesozoic is the Cenozoic. This is the current layer that is still being deposited in oceans, deserts and swamps all around the earth today. The Cenozoic is the first major layer where we find modern mammal fossils like cats, dogs, monkeys and humans. This layer, or “era” is often referred to as the age of mammals.

These three layers make up a sort of 3-layer cake. Just like a cake, the bottom layer went down first, followed by the middle and the top. Since fossils progress from fish at the bottom to humans at the top, we have clear evidence that life evolved through time.

Credit: prehistoricplanet.com

This is the skeleton of Dracorex hogwartsia. That’s right, hogwartsia as in… Hogwarts! It’s a fairly new dino having been discovered in the Hell Creek Formation in central South Dakota in the early 2000s and gets it’s name for its fantasy dragon-like appearance that would seem at home in a Harry Potter novel. It is a likely relative of Pachycephalosaurus and like its probable cousin, it is a head-butting herbivore. And of course, it didn’t breathe fire. Probably… 

2

A 72,000,000 year old 16 foot long tail of a dinosaur was found in the northern part of Mexico.

The dinosaur, a duckbilled or hadrosaur, is basically the prehistoric form of cattle. They roamed the forest & plains of North America, Europe and Asia in herds of up to a thousand. They communicated by funneling blasts of air through their large, ornate crests on their heads.

With their vast numbers, there are over 32 hadrosaur subspecies.

images courtesy of Reuters.

The three letter words of the genetic code are the same in every creature – CGA mean arginine and GCG means alanine in bats, beetles, beech trees, bacteria, even in archaebacteria living in boiling temps in sulphurous springs, or viruses - wherever in the world, whatever animal, plant, bug, you look at, if it is alive it will use the same dictionary and know the same code. All life is one. Seaweed is your distant cousin, and anthrax one of your advanced realtives. The unity of life is an empirical fact.
—  Matt Ridley, Genome: The Autobiography of a Species in 23 Chapters, Fourth Estate, 2000
cnn.com
Will mammoths be brought back to life? Liquid blood find fuels cloning hopes

Remember when woolly mammoths roamed the planet? No? Well don’t worry if you missed the last ice age – scientists have moved one step closer to possibly bringing the beasts back to life with the discovery of liquid blood in a well-preserved mammoth carcass in Siberia.

Researchers from Northeast Federal University of Yakutsk have uncovered a 10,000 year old frozen mammoth in Russia. While it may not seem particularly strange to find a frozen mammoth in a remote part of Russia, what makes this particular mammoth special is that researchers discovered it was preserved with liquid blood. The discovery of the blood was made in a rather inartful way when researchers excavating the mammoth accidentally jabbed it with an ice pick, causing the carcass to bleed. 

It’s still a bit of a question what can be learned from the blood. The researchers who made the discovery are calling this find the best preserved mammoth ever found. The researchers also claim that the mammoth blood may have “cryoprotective properties” with the blood found in a liquid state while temperatures at the dig site were  -7 to -10 C. The expedition is also associated with Hwang Woo-suk, a South Korean scientist who admitted in 2004 to faking data related to his claim of cloning human stem cells. 

So, we shouldn’t go out shopping for mammoth saddles just yet, although the South Koreans do appear to be very fixated on being able to clone a mammoth. What I find interesting about this find is that the mammoth carcass is only 10,000 years old, which is very recent history for humans to exist at the same time as a near-mythical extinct species. I think the extinction of the mammoth is more likely to be related to changes in the climate than over-predation by neolithic humans, but some people do think that they were hunted to exhaustion. Perhaps the researchers involved feel that if humans drove the mammoth to extinction, we owe them a solid by trying to bring them back. 

Another talk on phylogeny by the mighty AronRa 

It gets trying briefly if like me, you’re not wild about taxonomy, but, there’s really cool shit about the controversy leading to dinosaur conceptualizations we’d long carried until relatively recently. 

I’m so glad I got to live during the time we got to see dinosaurs transform from grotesque permutations of giant crocodiles, to, big cuddly plush.