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Old August 16th, 2017, 11:21 AM   #21
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Originally Posted by oshron View Post
then what about lizards? or fish? or crocodiles? or spiders? or the platypus? are they birds, too, because they also lay eggs?
Umm birds and Crocodilians are Archosaurs. So they're more diapsid reptiles. While lizards are lepidosaurimorpha and also are diapsids. When did fishes became birds. I don't see that logic.
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Old August 16th, 2017, 12:31 PM   #22

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I was re-reading the beginning of Chatterjee's book, "The Rise of Birds".

Putting aside his insistence that Protoavis is the great grandpa of them all, which mars his otherwise very good book, even he cannot point to a named species at the base of eumaniraptora as the progenitor. He does though present an adapted cladogram which puts the likes of Microraptor and Anchiornis to one side of deinonychosauria under the group, Averaptora, and includes, as most do now, Archaeopteryx under Avialae.

But to me this just causes complications as Anchiornis usually appears as a troodontid and Microraptor as a dromeosaur. But this is just saying really that they are "Deinonychosaurian avialans" and, with the use of Tetrapterygidae to include Microraptor, Xiatingia, Anchiornis and Aurornis, essentially makes four evolutionary strands possible from the base of Eumaniraptora to todays birds. Then even at the base of Avialae we spring straight into sub groups without discussion of what was basal to the group, as if they emerge fully formed without an intermediate step. Which comes back to the base of Paraves which splits straight into Scansoriopterygidae and Eumaniraptora without any progenitor to both groups, which is what of course we are looking for.

I'll come back to this tomorrow.
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Old August 16th, 2017, 12:44 PM   #23
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Originally Posted by Corvidius View Post
I was re-reading the beginning of Chatterjee's book, "The Rise of Birds".

Putting aside his insistence that Protoavis is the great grandpa of them all, which mars his otherwise very good book, even he cannot point to a named species at the base of eumaniraptora as the progenitor. He does though present an adapted cladogram which puts the likes of Microraptor and Anchiornis to one side of deinonychosauria under the group, Averaptora, and includes, as most do now, Archaeopteryx under Avialae.

But to me this just causes complications as Anchiornis usually appears as a troodontid and Microraptor as a dromeosaur. But this is just saying really that they are "Deinonychosaurian avialans" and, with the use of Tetrapterygidae to include Microraptor, Xiatingia, Anchiornis and Aurornis, essentially makes four evolutionary strands possible from the base of Eumaniraptora to todays birds. Then even at the base of Avialae we spring straight into sub groups without discussion of what was basal to the group, as if they emerge fully formed without an intermediate step. Which comes back to the base of Paraves which splits straight into Scansoriopterygidae and Eumaniraptora without any progenitor to both groups, which is what of course we are looking for.

I'll come back to this tomorrow.
We'll look forward in seeing your analysis of the study tomorrow.
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Old August 17th, 2017, 01:29 AM   #24

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This is probably not the answer needed...

Without going back beyond Paraves, I cannot find any species at the base that can be named, only those that are already classified in their own groups, such as Troodonts etc. What would have been a prime contender, the dromaeosaur Mahakala omnogovae, is late Cretaceous, so cannot of course be the ancestor, even though it has very basal features, and a quote from Science Vol 317 September 2007 by Turner et al

Quote:
The new taxon is small (~70 cm long) and possesses features absent in other dromaeosaurids but shared with early troodontids and avialans.
One thing that is certain is that nobody really knows, because the closer to the basal Paraves you get, the more similar all the species get, well, of course, and it cannot be disentangled without a lot more fossils being found. If the professionals still argue about where to place various species, then what chance for mere mortals.

If more fossils of Mahakala can be found much further back in time, then maybe it could be a relic that somehow survived from the mid Jurassic without evolving further, but that would be stretching possibility, particularly given the propensity of maniraptora to evolve as often as we change clothes. But the question remains unanswered of how a species with such basal features could evolve so late, and what did it evolve from, a species with features as advanced as it's contemporaries, and then gone backwards. Becoming a flyer and reverting to a non flyer, and even back again, and again, is one thing, and it seems a maniraptoran habit, but to revert to some very basal type, and even have some features that contemporaneous dromaeosaurs do not, is curious.

So, that's the best I, as a non professional, can do. I'll paste another quote from the same Science article, where the best they can do is come up with an approximate size for this as yet unknown dinosaur.

Quote:
Our analysis implies that the ancestral paravian had a body size of 600 to 700 g and was ~65 cm long, roughly the size of the largest specimens of Archaeopteryx or Sapeornis and entailing the size range reconstructed for basal deinonychosaurs. Thus, miniaturization preceded the avialan node and the origin of flight, and as a result, hypotheses relating ontogenetic or metabolic controls on miniaturization to flight origin in theropods must be equally capable of explaining the size reduction within ancestral paravians and the iterative trends of size increase in deinonychosaurs.

Last edited by Corvidius; August 17th, 2017 at 01:43 AM.
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Old August 17th, 2017, 04:14 AM   #25

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But... Because this can run and run.

Here we have Xiaotingia, hailed as the new urvögel a few years back. Also described as a basal dromaeosaur after having being a troodontid for a short time, but may still be a troodontid depending on which cladogram you look at, or want to believe. But whether it is a troodontid, basal dromaeosaur, avialan or even a Romulan, it comes after Aurornis, which may or may not actually be Anchiornis, work still progresses on this.

So, while we may never know who basal paraves was, I'll reiterate my previous statement that the so far, and to my knowledge, earliest known, within paraves, bird ancestor, is Aurornis, while it is still it's own species and not Anchiornis, and no matter what, birds start with basal troodonts, which is of course contentious. And I still go with Austinornis lentus as the first, so far known, modern bird.

The OP's research has concluded that the first bird is ?
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Old August 17th, 2017, 04:14 AM   #26

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Duplicate post
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Old August 17th, 2017, 09:26 AM   #27

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Originally Posted by Naomasa298 View Post
I thought Archeopterix was a Gaul.
He was actually a gull:
Click the image to open in full size.

[/rimshot]
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Old August 17th, 2017, 05:32 PM   #28
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Originally Posted by Corvidius View Post
But... Because this can run and run.

Here we have Xiaotingia, hailed as the new urvögel a few years back. Also described as a basal dromaeosaur after having being a troodontid for a short time, but may still be a troodontid depending on which cladogram you look at, or want to believe. But whether it is a troodontid, basal dromaeosaur, avialan or even a Romulan, it comes after Aurornis, which may or may not actually be Anchiornis, work still progresses on this.

So, while we may never know who basal paraves was, I'll reiterate my previous statement that the so far, and to my knowledge, earliest known, within paraves, bird ancestor, is Aurornis, while it is still it's own species and not Anchiornis, and no matter what, birds start with basal troodonts, which is of course contentious. And I still go with Austinornis lentus as the first, so far known, modern bird.

The OP's research has concluded that the first bird is ?
Well there are alot of fossils in universities and museum's collections that hasn't been completely researched nor examined as paleontologists from the past to present had collected so many fossils since the early 1900's that they just threw them in the inventory as if they just wanted to be the ones that collected the most. That is the only flaw of paleontologists and paleobiologists. So there could actually be that certain predecessor of birds and Troodontids. Heck there's probably a earliest known bird fossil that is among the many fossils that are piled together...neatly.

Here's an example of undiscovered species that are in natural museums that are not even properly studied nor examined explained in this link.
https://www.google.com/amp/s/www.the...rticle/459306/

https://www.google.com/amp/www.nydai...icle-1.2125817

So among those fossilized bones could be another undiscovered species of early bird that could've already told us.
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Old August 18th, 2017, 01:32 AM   #29

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As we know we are not going to arrive at a definitive answer, only a best guess that will vary between individuals, I just want to throw this, sort of spanner, in the works, or at least an added complication.

We know maniraptorans did a lot of evolving, and it continues to this day, for instance, some birds, due to ecological changes, can change the shape of their bills within a few generations. I don't have a species immediately to mind, but some can do this in a generation. On top of this, it has been seen that while crows are not migratory birds in the normal sense, groups of crows can split off the main group and migrate to form their own new colony. If the new ecological conditions require it, these colonists will begin to evolve away from the parent group, maybe a difference in their bill, maybe growing slightly longer legs, or maybe something that their bones cannot tell us, such as a new accent.

It is known that sometimes fresh waves of migration come from the parent group and, if evolution has not progressed too far, will interbreed with the colonists. This has the effect of reversing, at least for a time, the changes that occurred in the original colonists. This sort of behavior will not be visible in the fossil record, but, depending on the changes two types of crow may be visible in the fossil record, one very short lived.

What this is showing is that a species can appear and then be reabsorbed back into it's parent group. Mobility is a big factor in this of course, so as the first flying maniraptors appeared, no matter what group they belonged to, their mobility increased, and so the possibility of the situation I have described occurring, and thus further complicating out understanding of the evolutionary processes that led to the modern bird.

It is roughly estimated that since K-Pg a million species of bird have come and gone, so how many before the extinction, and also of all the other non modern bird maniraptors. How many different threads of evolution, how many species were reabsorbed back into their parent group.

It would be good if a progenitor was already in a museum, but would we even recognize it if we held it in our hands, I hope so.
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Old August 18th, 2017, 07:53 AM   #30
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Originally Posted by Naomasa298 View Post
I thought Archeopterix was a Gaul.
He had the GALL to call himself the first bird.
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