300 million years ago. this made me smile

Frequent landslides Appalachians were forming and reached 45,000 feet.

,onzeplumes,@wrabbit2000,

This is the stuff I love.

It just so happens that this period in time is one of my major interests. I live in "coal country", and these forests are where that coal came from. My grandpa worked in these mines for 40 years, all within about 5 miles or so of where I'm sitting right now, most considerably closer. He started working in them when they still hauled the coal out of the mines with mule carts.

This holler I'm sitting in, the hills on both sides of it have been hollowed out from mining. There are huge artificial mountains going down the creek that weren't there 80 years ago. They're called "slate dumps", and are the spoil piles of the slate and other stuff that came out of the mines that couldn't be sold for coal. You can spend a day crawling them - carefully! they're just piled up loose rock - and find more fossils than you can carry away from that time period. I used to have a Lepidodendron trunk I found in them. Not a big one - it was only about 3 inches wide and a 8 inch long or so section. I found it when I was a kid, and thought it was a fossilized snake at first because of the scales. You hear miners talk about "rock falls", where a section of the mine roof will just let loose and drop. They use long bolts, about 3 or 4 feet long (called, appropriately, "roof bolts"), to run up through those sections of rock and bolt them in so they don't fall and kill someone. Those rocks are the stumps of ancient lycopsid trees.

"Tree" is a misnomer. they weren't trees like we know today, despite the fact that they got up to 140 feet tall and 6 feet in diameter. They had a rough, scaly green bark on the outside, and a hollow lignin stem beneath it. More like a thick bamboo stem (without the nodes) structurally than trees. Life cycle from sprout to 140 foot dying behemoth was only about 15 years for them. The lycopsids like Lepidodendron still have living relatives around here to this day, although considerably smaller. We call them "ground pines", and they only get about 4 inches tall, with the stems that bear spores spiking up maybe 8 or 10 inches when they reproduce. Interestingly, those spores from them are highly flammable. They were used back in the day as flash powder. I think the technical term for what grows here is "Lycopodium". "Ground pines" is easier to remember. They still have the branching structure of the Lepidodendron crowns, and stay green all year round, just like the ancient lycopods probably did.

The average temperature around here (and keep in mind that "here" was right around the equator then) was about 104 degrees.The CO2 content of the atmosphere then was about 1500 ppm. Contrast that with today's CO2 density of only 380 ppm. nearly 4 times as much CO2, and yet life thrived. Imagine that. The oxygen content of the atmosphere was about 35%, compared to the 21% we have now. The high oxygen content from the huge rain forests that grew here had a couple of ramifications. One was forest fires. Forest fires were endemic, and raged out of control from something as simple as a lighting strike. There is still ash and charcoal from them to be found in the deposits in the mines. The burned over land didn't lie fallow for long - there was such a profusion of life that it quickly reclaimed any vacant acreage. And, as I mentioned before, it grew FAST when it did it. Some species were quicker to take over the burned out sectors than others, taking advantage of the suddenly opened spaces. We see the same thing today with "trash trees" like locust trees taking over poor, over worked or burned over land in thick stands.

Another result of the high O2 content was bugs. BIG damned bugs. Apparently, they could take advantage of the oxygen easier when it was in high concentrations like that, and so grew bigger as a response. I've seen roaches from the mines near 4 inches long, and have heard that some grew up to a foot long. Damselflies (erroneously referred to as "dragon flies" - but the distinction really only matters to bug scientists) called "Meganeuria" had wing spans of 30 inches. There is some speculation that the atmospheric composition may have been thicker as well, and supported bigger bugs better in flight. A centipede called "Arthropleura" crawled these hills that was 8 feet long, and it apparently had none or damned few natural enemies. Unlike the centipedes today which are carnivorous and at times poisonous, Arthropleura has only been found with pollen, spores, and leaf litter as a gut content, so speculation is that it was herbivorous.

Plants were lycopsid "trees" like Lepidodendron and Sigillaria, lower trees (the understory or lower canopy of the rain forests) that were tree ferns, some of which (now extinct) bore nut-like seeds instead of spores, and were called "seed ferns". Some ferns were shrubs (bigger and smaller shrubs) and some were liana-like vines climbing through the forests and tangling up the trees. In more open and/or swampy areas, stands of "horsetails" (Calamites) could be found growing in thickets, some grew 30 or 40 feet tall. Horsetails today get 10 feet tall at their largest. Calamites thickets could be found ringing lakes and ponds, and making the edges of creeks and rivers near inpenetrable, like modern "cane brakes".

There were spiders (although most agree that they were not poisonous, as apparently poison gland had not yet evolved), and bugs of all kinds living off the rain forests. Lizards and amphibians to eat the bugs and each other, and fish too - whatever was convenient, I guess. There were things in those sluggish, peaty waters. Some of the amphibians grew up to 8 feet long or so. I've often wondered if they were good eating, because you'd be able to feed a family of 4 off of just one of 'em for a week! Unlike modern frogs and salamanders, though, those amphibians had TEETH. Serious teeth. Cross a gator with a mud puppy, and you get the idea.

Bill DiMichele is one of the guys who studied the 4 square mile Illinois rain forest in the OP. Several of his papers on the topic can be found and downloaded from that page. I read a lot of his stuff when I was doing a series of reconstructions of a Carboniferous period rain forest. Of particular interest to me were the censuses they took. It's good to know what kind of plants, their distribution and growth density you're dealing with when doing reconstructions. It was that very forest, and the censuses from it, that assisted greatly in my reconstructions.

Here are a few of them:



This is an aerial overview.





A little closer...




From ground level looking upwards - a hiker's eye view...


AAAAND - God only knows what lurking in there waiting for you!:



These compositions are mine, original to me. They're not really public domain, but I don't care if you download 'em or use 'em, just as long as you're not abusing them or doing violence to them.

The tall trees with bushy crowns and brown fruit are Lepidodendrons. The tall trees with forks at the top and long spiky leaves are Sigillaria. The tall trees with broad leaves are Cordaites, and the tree ferns in the understory are Alethiopteris.

The census data and distribution of them I got from DiMichele's work, so it's as scientifically accurate as I could make it. I had to fiddle with the models for the plants a bit to get them as I wanted - the originals had brown bark, a big fat no-no for these plants, most likely, as their bark was photsythetic just like the leaves, and so probably green, rather than brown. Chlorophyll has been found in it, which to me is a pretty dead giveaway. The main problem with these pictures that I'm not happy with is the Lepidodendrons. They apparently only grew those bushy crowns at the end of their life cycle when they were reproducing. Technically I guess the crown is a "fruiting body". Because of that, MOST of them, say roughly 9 out of every 10 (between 85% and 95%), should just look like green hairy telephone poles, without the spreading crowns. I still need to work on that, but my 3d modeling skills leave a bit to be desired. Mostly all I need to do is lop off the crown, put a cone there, and then line the upper third or so of the trunk with green "fuzz" or "hair" for the leaves. The "scales" on the trunks are actually scars where old leaves fell off as the trees grew, so we know that leaves grew directly from the trunks.

Another problem, perhaps, is the atmosphere. I'm not sure what the color cast of that combination and concentration of gasses is. There probably ought to be more mist as well, and more - and perhaps thicker - clouds, because of the humidity. They WERE rain forests, after all!

One day, maybe, I'll get the pictures where I want them. I'm a hellion for accuracy.

Finally, I said these Lycopods like Lepidodendron and Sigillaria have modern cousins still living here, so I'll include a couple pictures of those that I took on a walk Grace and I went on back in January:



Note the spore "cones" on the tall spikes. they were reproducing at that time. Spore cones have also been found in a fair abundance for the Carboniferous lycopods as well. I've always wondered if their spores were as flammable as the modern ones - that, combined with 35% atmospheric oxygen could be a pretty bad brew under certain conditions. Imagine those 100 or 140 feet tall, and with the cones hanging off the branches rather than on separate spikes above them, and you'll have a fair approximation of what a Lepidodendron looked like in full fruit.

And a bit farther away to show coverage better:




OK. I'm done spamming your thread now!

thank you ninurta, love all the fascinating information you have shared,I live in coal country too, my grandpa and dad were blacksmiths that put shoes on the mine mules.

I was thinking how awesome it is to feel the earth beneath my feet and imagine the past, I'm strange like that.