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I spent two days observing the coast of half moon bay along a 2 mile stretch of land. I made this because if it is true, it would place an extinction event between 2 recorded ones.

I am a new member of this forum, and I hope some of you will enjoy a somewhat different approach to the topic of dinosaur extinction. As a philosopher and a computer software architect for over 50 years, I dig things a different way. Of course I have always been interested in dinosaurs. What got me really excited about the problem of dinosaur extinction a few decades ago, was learning that there are two families of birds. Birds with teeth all died out with the dinosaurs. Birds without teeth lived on to be the ancestors of the birds we have today. Thinking about this led me to develop "The Last Gasp Theory" of dinosaur extinction. I wrote a book about it and self-published on Amazon in 2008. (I am not trying to sell a book here, I'm going to give a quick synopsis of the ideas here.) We know that dinosaurs and mammals lived at the same time. How could it be that all the dinosaurs (except birds without teeth) died, while the mammals lived on? One way to describe this would be to say that the environment the dinosaurs were adapted to rapidly disappeared all over the world at once, while the environment that the mammals were adapted to, continued on to the present day. But how can there have been two separate environments at once, that extended around the world? The answer that comes to my mind immediately, is the atmosphere. If we assume for this argument that the atmosphere of the Earth at the time of the dinosaurs contained a much greater amount and percentage of oxygen, several things could also be true. Dinosaurs could be a special adaptation to a higher oxygen environment, with special lungs, stronger muscles, and perhaps stronger bones than other animals including mammals. These of course are things that might not be obvious from first examination of their fossils, but might be inferred from the support of the larger specimens, the depth and inclination of footprints, and other things you will think of. Looking at mammals from this perspective, you might notice that the major traits of mammals all point to an adaptation for living in cold weather at least part of the time. Hair, constant body temperature, live birth, suckling the young. Now lets add one more trait that is not obvious to us today: they were and are adapted to thin air, which the dinosaurs were not adapted to (except perhaps the birds without teeth.) In a thicker, denser atmosphere, the environment near sea level would have been warm. A thicker atmosphere also leads to a faster decrease in air density with an increase in altitude. Assuming the dinosaurs were adapted to the environment of the lowlands, and mammals were adapted to the only place it could be cold, at higher altitudes, perhaps they lived separate lives, almost as if they lived on different planets.. (by the way, Hal Clement's science fiction classic "A Mission of Gravity" offers a perspective on this idea.) The mechanism of the extinction is simple. A large asteroid hits Earth and scrapes a 60 mile (100 km) trough thru the outer crust. This releases a humongous amount of abiotic hydrocarbons. These hydrocarbons are eaten by bacteria, who convert them to CO2 and water. Very rapidly, the environment that favors the dinosaurs and their cousins in the air and the oceans, can no longer breathe. Birds with teeth go along with them. Birds without teeth, who have perhaps adapted to thinner air, live on and we get to call them "dinosaurs". Many mammals move downhill to expand their territory. One thing this suggests is that we might want to expand the label of dinosaurs to other animals that did not share their common pelvic structures. Another is that this could happen again, to us, with another large Earth impact. Of course, we will have more to worry about than thin air if that happens. As an aside to this theory, I'd like to offer a conjecture. I think that one of the influences that has driven evolution on a larger scale, is both decreases and increases in oxygen. Of cou8rse the development of plants has increased the free oxygen or elemental oxygen in the air, making oxygen-breathing animal life possible. I also think the total amount of oxygen in the air goes up and down over millions of years. The mechanism as I imagine it, is that meteors, asteroids, and perhaps microcoments containing water rain down on the earth constantly. Then H2O disassociates into hydrogen and oxygen atoms in the upper atmosphere. The action of the solar wind strips off the lighter hydrogen ions which are lost to space. The far heavier oxygen atoms fall back, and increase the concentration in the atmosphere, which at one point benefitted ceolophysis . becoming the grandaddy to the dinosaurs. At other times, abiotic hydrocarbons are released and thin the air again. I hope some of you have enjoyed my introduction. Even though it is not based on fossils except in an indirect way, I hope some of you can use these ideas. You should have seen me at 12 years old encountering dinosaur fossils at a museum in Albany NY in the mid 1960s! -Brad Jensen

Hi everyone, So I just finished sizing down my fossils. By this, I mean I cut away the excess rock, so the fossils can fit in a frame. While cutting, I had some interesting thoughts come into my head, forming a theory. I found one plate with three Diplomystus dentatus on it. Two small ones, one larger one. I am attaching a picture of this one. I also found another plate with four or five Knightia. Judging from what I found, my theory is that Diplomystus and Knightia were schooling fish. By this, I mean they travel in groups. It seems like a possible theory, because I found so many Knightia and so many Diplomystus in the same plates. On the other hand, I have found more individual Knightia and Diplomystus then multiples in single plates. This is just a theory, just so you know. I honestly don’t know what is truth. On a side note, I did learn that Diplomystus were surface feeding fish, The shape of their mouth shows it. I found this information on a source on the Internet. It makes sense. The way their mouth is shaped, it would make it easier to surface feed. Trust me, I’ve fished for Bass, which have a similar mouth, they feed on the surface occasionally. Top water fishing for bass is fun, but that’s not the point. I’m learning interesting things every day. Really makes me want to get into paleontology more. Jared

Hello everyone! I just started learning about dinosaurs and am very excited! I’m trying to grapple with some weird things about the T-rex and was wondering this: could T-rex have been a “persistence” or endurance hunter? I’ve been reading things that say the T-rex was probably slower than most of its prey. Rather than out-sprinting its prey, might T-rex have simply been in “better shape”? That is, might it have been capable of sustaining an elevated pace far longer than its prey, then relying on superior tracking skills to relentlessly close on hiding prey attempting to cool down and recover from exhausting sprints? I’ve heard this method proposed for early hominids and wondered if T-rex might also fit the bill, but I really don’t know what goes into a successful “persistence predator”. Thank you all for being understanding - obviously I’m new at this - and thank you especially for not laughing at yet another monumentally uninformed crackpot idea! https://en.wikipedia.org/wiki/Persistence_hunting

Awhile ago, I posted some unknown recepticulites and didn't receive a definitive identification. Since then I cleaned up a fisherite which had a central protrusion on it. My mind went back to the unknowns and I semi convinced myself that these are "baby" fisherites and that the large "sunflower" head comes with age. The unknowns were about the size of the protrusion on this fisherite. Here are pictures of both. For all you wise paleontologists out there, is my theory plausible??? The babies: The adult:

I recently came across the young earth theory (the theory that earth is 10.000 years old and dinosaurs coexisted with humans and traveled with Noah and his ark) and of course i thought it was unfeasible but one common argument they keep having is why are we finding soft tissues, proteins and other biochemicals in fossils like triceratops, t-rex and other dinosaur bones of course that doesn't mean DNA BUT they shouldn't have been preserved because such biochemicals don't get preserved after so much time. Another one is that some old fossils are still close to the surface when they should be buried really deep. So what are your thoughts on these arguments, in my opinion this theory is ridiculous but i'd love to learn the answers. Thanks (PS sorry for asking that many questions these days its just that im new to the forum and have lots of questions)