Neuropteris ovata and Neuropteris scheuchzeri (gient tree ferns).
I live in Tulsa, Oklahoma, and I hunt fossils. I am a lucky man. There is fossil bearing rock exposed in outcrops, by erosion and excavation all around the area. Today when someone calls something a fossil, they mean it's really old, older than dirt. Paleontogists define the word strictly and only as the naturally preserved remains or traces of animals and plants that lived in the geologic past more or less prior to that tiny sliver of time we call human history, and generally the deep past. Hundreds of millions of years ago. But "really, really old" is not the root meaning of "fossil." The word fossil is from the Latin fossilis, meaning "dug up," though most of time I pick them up, pry them out, and/or break them out of a rock with a hammer and chisel. I hardly ever dig them up. I let Nature or the Hand of Man as represented by the earthmoving equiment of State Highway Department or quarries do the digging for me, mostly. What I do is fossick for fossils. Fossick is a word donated to English by Australian gold miners, and means to rummage about old diggings.
A line of 'dozers at Hwy. 75.
Seminole Formation cut at Hwy. 75. Limestone above, shale below. Fossil site just forward of my car.
Fossils are found in sedimentary rock, formed from material deposited by the action of wind and water. Sandstone, limestone, shale, are all sedimentary rocks, and Tulsa has all these as bedrock, layered like a cake. The rock in Tulsa dates back to the later half of the Carboniferous Period, 286 to 325 million years ago. The fossiliferous shale shown above is, to give a very rough estimate, about 300 million years old. Give or take. That's 1/15 of the time of the four and half billion years or so the Earth has existed. It's 50,000 times the 6000 years elasped since God created the Earth, as per the King James Version cherished by Creation "Science." It's 75 million years before dinosaurs began to rule the Earth. Give or take. Amphibians had their heyday in the Carboniferous, and early reptiles were the latest thing in terrestrial vertebrates, and insects were the first living things to grow wings and take flight. We're talking dragonflies with two foot wingspans. Plants reproduced by wind born spores, and needed to be close to water. Innovations such as true seeds, fruit, and flowers had not yet evolved and were in fact far in the future.
During the Carboniferous, due the action of plate tectonics, a good deal of the planet's land was, well, massing in the over the south pole and the high latitudes of the southern hemisphere. Lots of landmass in high latitudes sets the stage for an ice age, which indeed occured at this time. Tulsa was situated in the tropics. As the glacial ice advanced and retreated, sea level fell and rose. Coast marshes would be drowned by the sea, or covered by the sand of a river delta. The Quachita orogeny was also occuring around that time, in Arkansas, and south of Tulsa in SE OKlahoma. Mountains rising higher than the Rockies, erosion wearing them down, to the still rugged nubbins we still refer to as "mountains" here in Okieville.
 
Marine invertebrates: Crinoid stems, and a brachiopod,
Thus far I have collected two different kinds of fossil "assemblages," marine invertebrates, and terrestrial plants. Road crews have recently been at work, widening Yale Ave. between 71st and 81st Streets, and widening and lowering Highway 75 at 71st Street, tearing into the rock of the Seminole formation, and exposing a motherlode of plant fossils at each location. Gleaning after quitting time, but wearing my hard hat and reflective orange vest as protective coloration, I have greatly enhanced my collection of plant fossils (filled the garage full of rocks, from my wife's point of view).
Seminole Shale seam at 71st and Hwy. 75
Annularia stellata (Giant Horsetail foliage) collected at Hwy. 75
Calamites Suckowi (Giant Horsetail stems) collected at Yale Ave.
Yale Ave. site
One last note: I'm not really a paleontogist, I just play one on this blog. If I have misidentified any of the fossils, or have otherwise gotten the details wrong, I apologize in advance to any professional paleontologists, and will be grateful to recieve correction. Happy trails, preferably trilobite trails, 'til next post.
6:16:44 PM 
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