Paleontologists have discovered what very well might be the oldest known dinosaur, if in fact Nyasasaurus parringtoni is a dinosaur at all. A study published in the journal Biology Letters is describing a new species of prehistoric reptile that appears to predate the previous earliest-known dinosaur by 10 to 15 million years. That not only stands as a new superlative in dinosaur classification, but if confirmed, it fills a gap in the evolutionary timeline that's been puzzling scholars for years.
Nyasasaurus parringtoni is a fairly small relative of the massive reptiles we've come to associate with the word dinosaurs. Measuring between 6 and 10 feet long, it walked semi-upright on two legs and weighed somewhere in the vicinity of 45 pounds to 130 pounds--a wide range, we know, but considering researchers are working with just one upper arm bone and six vertebrae, all of these figures are assumed to be very rough approximations.
Far more important than precise physical specs is the dinosaur's age. The early evolution of dinosaurs is kind of tough to parse, particularly because there were a lot of reptiles on Earth at the time, some of which may have evolved dinosaur-like traits independent of the dinosaurs. Discerning the difference using only the fossil record as a guide is difficult, but the researchers authoring the paper maintain that a few of the features they have extrapolated from their skeletal specimens suggest very strongly that it is indeed a dinosaur--and the earliest one yet discovered.
If they are correct, Nyasasaurus parringtoni would fit right into a hole in the evolutionary chain of events, dating to right around the time paleontologists think dinosaurs split off from their oldest relatives and became the distinct group that would later go on to dominate the Earth for 100 million years. That means that perhaps Nyasasaurus parringtoni is the oldest dinosaur ever discovered, or maybe that it's not (the research team itself has stopped short of formally making that claim based on the incompleteness of the skeleton, though the evidence they put forth suggests that it is). Either way, the species is a key piece in the puzzle of dinosaur evolution, one that would've shared the planet with dinosaurs' oldest known relatives and that very well may have kicked off the age of the dinosaurs.
If birds came from dinosaurs then something like dinosaurs can and should have come back from birds. The fact that dinosaurs have not come back tells us how they became extinct. That birds and their travel have made them highly infectious, killing anything that ells that is biologically close to them. Yes an asteroid hit, but it only made the bird’s masters of migration, and therefore the winners by infection.
Extrapolated, we are also the winners by travel with extinction of the Neanderthal occurring when the boat leads to travel and trade and rapid transmission of viruses. Without trading resistant DNA along with decorative shells effectively enough the Neanderthal also died out.
However, we can confirm this explanation in a modern day model of the American Indians. Europeans had accomplished world trade, world travel, and world scale disease. This killed most Native Americans, thus allowing a plow basted food system that sustains double the population of hunting and gathering to almost lead to their extinction. Perhaps in another five hundred years from an archeological perspective they already appear to be extinct.
birds evolved from dinosaurs because the conditions during that long period favoured that change. There could certainly be a reversal to a more dinosaur-like form but it would take the proper conditions to be sustained for many many thousands of years.
Yes, but many millions of years have passed allowing for far more chances for a new dinosaur like creature to re-exist. Besides that, I have argued several other confirmable instances where this premise is also arguably true.
This is far more logical a solution then a simple asteroid fell selectively making only the dinosaurs extinct. I know you will say lots of animals went extinct, but only one entire species group went extinct. There is a big difference between the two. Dinosaurs filled almost every evolutionary, and environmental niche, and they all are gone today, and stayed gone.
Mammals have come to dominate the ground after the general demise of the dinosaurs. Only a few species of birds have managed to return to the ground, or have never left, because they still have environments where they can remain relatively safe. Still, if for some reason the skies (or trees) became inhospitable, birds would return to the ground and either go extinct from over-predation or possibly evolve to a more dinosaur-like form and hold their own.
As I understand, dinosaurs and trees were much bigger because the oxygen level was higher in that period. It is at 21% presently, but was around 30% in that period.
So I doubt dinosaur could come back today.
The oxygen level is a good point both modern birds and dinosaurs have air sacs for increased metabolism. Perhaps a genetic evolutionary trait from fish used for buoyancy turned back on. Large insects existed in the oxygen rich time period of the dinosaurs and today only small insects can live. I would expect to see the same thing happen in new dinosaurs to evolve from birds. Then we should have seen dinosaurs from birds, but not the massive ones of the cretaceous.
Far Out Man,
The Mammal-like Reptiles or Therapsids first appeared about 285 million years ago near the beginning of the Permian which is well before the dinosaurs. They evolved quickly and many different groups arose. They were very successful until about the end of the Permian, about 245 million years ago, when something catastrophic affected the earth and nearly all of the species then living died out. New species evolved rapidly to fill this empty habitat, among them the first dinosaurs and a few million years later the first mammals.
So as long as you do not count something catastrophic yea mammals rule the Earth. But what prevents another something catastrophic happening again? It is really luck we dominate now and not a true competition between the dinosaurs and mammals. In this case the winner did not win by the slow process of evolution.
Should another catastrophic event happen again, maybe the birds? And if the birds win the next contest, the since they are believe to be descendants of dinosaurs, in effect the dinosaurs are the true winners!
Maybe the current sea turtle is the current winner, lol.
It should be noted that Therapsids went extinct in full Pangaea, one land mass. Meaning the same rule applies. Migration by land would be just as infectious during a Pangaea as birds migrating out of Pangea. A meteoroid would only radically contribute to migration. The winning relative and their movements would be constantly infectious endlessly driving Therapsids extinct. Because of this process the dominant migrating relative needs a much closer look. We may someday see the extinction of Neanderthals in the remains of their teeth possibly proving that it is an entire process, and not just a meteoroid.
you are right of course. There is even a chance that the next catastrophe might catch mankind at a low point after an earlier man-made catastrophe prevents us from being ready. It is impossible to imagine everything that might affect the Earth in the next few billions (perhaps trillions!!) of years.