HOLY HOLOCENE! (Part 2) 


More on what happened after the last big smuck. 


The earliest known placental mammal. (Eomaia scansoria - 125 mya excavated in China) Is this our great great great grampa?

When the last biggie smacked into the Earth 65 million years ago, it really changed things around in a big way. It's possible it wasn't an impact that did the final number on the dinos, (recent evidence suggests the Chixalub crater in Yucatan may have happened earlier than at first thought, which possibly means something else did it, but I think the jury's still out) but whatever it was cleared just about every overly huge creature from the face of the Earth. At this time that was mostly large dinosaurs. At that time, mammals already existed (numerous small marsupials, and bug eaters our ancestors) and because they were able to flee to safety underground, they survived.

The Earth, free from all the big predators, was now a planet-sized free range pasture for the smaller mammals. When predators aren't around, the whole dynamics change, and whatever creatures exist have fewer restrictions placed on them. They are free to grow large and conspicuous in size, because there is nothing chasing or eating them. Because of this, the smaller mammals survived at larger sizes and began to adapt to the various conditions that existed in this new world.

The age of mammals had begun. But this didn't rule dinos out completely. The smallest dinosaurs also survived this climate changing disaster, and began to adapt to the new conditions also. Many discoveries confirm that feathers are actually modified scales, and thus the small dinos became the birds we know today. Some became large and flightless, some smaller as we're used to seeing today. But some birds didn't make it that far. For example, the Diatrima was a massive bird that stood maybe twice as tall as a man, had a two foot wide head (mostly beak) and could easily take your head off with one bite. This bird (along with others similar to it) did not survive to today, possibly because it was hunted by early man. Mammals also took on these monstrous proportions. It's amazing how few of these amazing creatures have any notoriety at all today. In my opinion, they should do another Jurassic park, but do it for the incredible age of mammals; the Cenozoic period (Cenozoic Park doesn't have as cool a ring to it though)



The massive, flightless and turtle-beaked Moa lived in Hawaii as recently as 1500 years ago, when Polynesians first arrived there.




A sketch I found of Dyatrima. Amazingly, a Google search of this bird turns up almost nothing. A tall man would reach this bird's neck.


This world became truly bizarre. You can learn about much of this if you have kids. The kids books these days contain a lot of cool factual stuff about this early age of mammals, and have interesting pictorials of the creatures. This is what caught my eye. (not surprising, I know)

The only creatures to make it through to today's consciousness seem to be the Woolly Mammoth, Woolly Rhino, and the Sabre Toothed Cat (not tiger) But by and large, the creatures that dominated at this time were some of the most frightening and the most bizarre in Earth's history. The largest ever land mammal, the Baluchitherium, was a grandparent of today's Rhinos, but looked very little like one. Picture a massive camel-like creature whose kneecap was higher than the head of a six foot man, and stood about twenty five feet tall. It fed from the treetops and probably didn't have much to worry about in the way of predators. There were many animals of this or slightly less size, and the landscape must have been absolutely foreign with the sight of these creatures dominating the treetops.


Baluchithirium as it would appear next to a horse and rider, and a more detailed illustration I found.

The Andrewsarchus was the largest ever mammalian predator. It looked something like the "Wargs" from the Lord of the Rings movies. They were like massive wolfish hyenas, with heads spanning three feet! Standing taller than a man, these deadly things were likely the most devastating killers ever to walk the Earth since the dinosaurs. In fact, because they were warm blooded, they may have been faster and more deadly than the Velociraptors and T-Rex's of movie fame. But I'm wildly speculating here, and nobody knows for sure.



An illustration of the fierce Andrewsarchus, the largest mammalian predator of all time. This big guy had a three foot head and stood as tall as a man (while standing on all four legs) This thing is the stuff of nightmares, and it existed!


Horses were another astonishing find. There is a clear and detailed fossil record of the development of horses. In the earliest finds, they were the size of small dogs. They had three hoof-like toes (the front toe eventually getting larger to become the single hoof we know today) Ironically, these creatures would have been hunted by the birds of the day, like the diatrima, or the Argentaris magnificens, with its TWENTY THREE FOOT WINGSPAN. This giant was the largest bird able to fly.



An illustration I found of a huge (and extnict) predatory bird (Gastornis) eating a tiny prehistoric horse called a Propalaeotherium.


Early elephants at first looked like today's pigs. The trunk and tusks underwent various varieties and configurations, including one creature that had huge, flattened and curved tusks arranged like a scoop, that it used to scrape muck from the bottom of marshes, or maybe to dig in the earth. There were varieties whose tusks curved downward instead of upward. Ancient bear species (the Cave Bear) were twice as large as today's bears, which are about the same size as the giant sloth of this era. There were bucks whose
antlers spanned twelve feet, and giraffes that looked like moose.



Moerithirium. The ancestor of today's elephant was pig-sized and had no trunk.

The number and variety of mammals during this time is a fascinating thing to study, and, thanks in part to my son's illustrated books, one that I intend to learn a lot more about. You can learn more about this incredibly underrated period in Earth's history and the animals that lived during this time pretty easily with a few google searches, but here's a couple:

http://darwin.bio.uci.edu/~sustain/bio65/lec02/b65lec02.htm
http://www2.nature.nps.gov/geology/parks/paleocene.htm
http://www.horseshoecrab.org/evo/ceno/cenozoic.html
http://www.palaeos.com/Cenozoic/Cenozoic.htm
 

Posted: Mon - May 16, 2005 at 12:39 AM          

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