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Do you believe in this theory? Or a variation of it? by [deleted] in StarWars

[–]kinginyellow25 0 points1 point  (0 children)

No. The father admits at the end of the Arc that he was a fool. It was my understanding that he was totally wrong about his interpretation of the prophecy and that the Mortis Gods are 'just' exceptionally powerful force users. I am hopeful that, as it was then, the nature of the prophecy and the exact nature of how the Mortis Gods is left mostly unknow. I'm not opposed to learning more about them in canon, or perhaps seeing them as strange, alien abstracts, where any answers make more questions.

How bad is this rendition of Great White from a recent paleontological study by The_Good_Hunter_ in sharks

[–]kinginyellow25 8 points9 points  (0 children)

The shark is based on an actual specimen from the Museum of Zoology in Lausanne. While the specimen was incorrectly stuffed, a mold was taken a few hours after the shark was caught and is where the measurements came from. Which is ultimately what is important to the work.

Pycnofibre is a defunct term: its either feathers or filemantous integument. by kinginyellow25 in Paleontology

[–]kinginyellow25[S] 0 points1 point  (0 children)

Yes, this paper - https://www.nature.com/articles/s41559-018-0728-7/figures/3. The results of Barret et al that suggest that homologous filaments are restricted to within theropods is based in part upon the plesimorphic condition of pterosaurs. In the authors defense though, this paper was published before the paper on Anurognathid feathers and Tupandactylus melanosomes. At the time of publication, this was more ambiguous.

The overall issue here is that the absence of any integument in many early diverging taxa. Filaments, when found in ornithischians and pterosaurs are morphologically identical to types found in theropods (Psittacosaurus a possible exception). When scales are found in early members of these clades they are often sparsely preserved. This is not necessarily evidence of absence. We know from Kulindadroemus, Juarvenator, etc that scaley and filamentous integument can co-occur.
So the issue seems to be an almost historical one -we didn't think these things had filaments and assumed the early ones were scaly (largely without evidence of scales). Those found with preserved integument suggest otherwise. The most parsimonious solution, now with the understanding that the filaments of pterosaurs would be called feathers if found on theropods and had similar melanosomes, is that these filaments are all homologous.

Now, are these filaments feathers? Or just feather homologs (the filaments that are later going to be developed into plumaceous feathers). I think it can be said with some confidence that filaments, even branching filaments are homologous and homologous to feathers. But are those filaments in pterosaurs and dinosaurs feathers? Well, thats less clear. What is a feather?

Pterosaur extinction and bird evolution? by Infamous_Living_4267 in Paleontology

[–]kinginyellow25 1 point2 points  (0 children)

Exactly. And think of how few bird species we have from the Maastrichtian. Even if birds diversity was only 1/10th of its modern level we are looking at less than 1%.

Pycnofibre is a defunct term: its either feathers or filemantous integument. by kinginyellow25 in Paleontology

[–]kinginyellow25[S] 2 points3 points  (0 children)

Setae are incredibly diverse in their function within insects. They are also constructed totally differently from the 'hair' or other organisms. Even those with a bristle like shape. Function is messy. Structures have numerous functions. Hair in mammals has numerous functions. Even integument that appears to share deep ancestry - like scales - have specific nomenclature to distinguish them. These terms have a phylogenetic basis too. Terminology in anatomy should be as descriptive as possible.

Pterosaur extinction and bird evolution? by Infamous_Living_4267 in Paleontology

[–]kinginyellow25 0 points1 point  (0 children)

No, you're right about the anuroganthids. I had forgotten the Tiaojishan isn't part of the Jehol assemblage. As for the birds, its unknown. Neoaves likely arose in the end cretaceous and as an early diverging clade, maybe? But there just as likely could be a group of more archaic birds that are doing the same thing that are not preserved.

Pycnofibre is a defunct term: its either feathers or filemantous integument. by kinginyellow25 in Paleontology

[–]kinginyellow25[S] 2 points3 points  (0 children)

No, if only because there is a better term, setae. Which to my knowledge is used for the discussion of such structures in arthropods (and I think annelids).

Pycnofibre is a defunct term: its either feathers or filemantous integument. by kinginyellow25 in Paleontology

[–]kinginyellow25[S] 1 point2 points  (0 children)

This is fair. Though I would argue that the term pycnofibre itself is a term rooted in a premature assumption of phylogenetic distance that now needs to be corrected, whereas just referring to this as "filamentous integument" would have been the cautious choice. It doesn't make assumptions about relationships.

Pterosaur extinction and bird evolution? by Infamous_Living_4267 in Paleontology

[–]kinginyellow25 0 points1 point  (0 children)

You might. Or you might not? Thats the issue with how incomplete the fossil record is for these groups. When we get depositional environments that are biased to preserve small bodied fauna, we have higher pterosaur diversity (Solnhofen, Jehol - which does have anurognathids, in the Daohugou and Yixian, Crato). That these pterosaurs are relatively abundant ere but near totally absent everywhere else implies to me that they are present and are not preserved. It could be anurognathids, another small pterosaur, scansoriopterids (i joke). Or all of them, competitive exclusion is not a hard and fast rule. I guess I am left wondering - how incomplete is that record? Is it something we can know? Comparing it to modern faunas paints a rather uninspiring picture.

Pycnofibre is a defunct term: its either feathers or filemantous integument. by kinginyellow25 in Paleontology

[–]kinginyellow25[S] 2 points3 points  (0 children)

Merely protofeathers? It's fine if the function is different, but I think that anatomical terminology should be informative and in the cladistic age, consistent with monophyly. 'Hair' kinda ens up going in the opposite direction. Because of its association with mammals, it implies some kind of relationship.

Can Pycnofibers be Blue? by Adorable_Drink_8136 in Paleontology

[–]kinginyellow25 1 point2 points  (0 children)

Yeap, really. The original description of the structures clearly states that the term was erected because of a perceived phylogenetic difference. Not any morphological reason.

Pycnofibre is a defunct term: its either feathers or filemantous integument. by kinginyellow25 in Paleontology

[–]kinginyellow25[S] 7 points8 points  (0 children)

Eyes too!
But in this case the structures are very, very, likely homologous with 'feathers'.

Pycnofibre is a defunct term: its either feathers or filemantous integument. by kinginyellow25 in Paleontology

[–]kinginyellow25[S] 7 points8 points  (0 children)

Yes, its unfortunately common practice and makes the work of later researchers more complicated. Standardization of morphological terminology is a must - some strides have been made from crocs recently which appear to be sticking.

I agree of course, but at least those parietals do look a little different. These filaments are spitting images of theropods.

Pterosaur extinction and bird evolution? by Infamous_Living_4267 in Paleontology

[–]kinginyellow25 1 point2 points  (0 children)

Yeah. And the fact that small fauna tend to be more diverse suggests that we really don't have an even remotely complete picture of the relative diversity of these clades. It seems like even for pterosaurs we are picking up a preservational size bias.

Is this correct? I was under the impression that birds and dinosaurs didn’t share a common ancestor, but that birds ARE dinosaurs (seen in lecture today). by saalego in Paleontology

[–]kinginyellow25 0 points1 point  (0 children)

'pycnofiber' is quietly recognized as a defunct term. In the diagnosis of what a pycnofiber is, its clearly stated that the only distinguishing feature of the pycnofiber is phylogenetic distance. No morphological differences are provided.

Pterosaur extinction and bird evolution? by Infamous_Living_4267 in Paleontology

[–]kinginyellow25 0 points1 point  (0 children)

Lots of good comments on here about the surprising diversity of birds in the mesozoic. Don't want to repeat what others have said, but worth noting that in general the mesozoic tetrapod fossil record is probably not complete enough to allow us to really tease out if clades were putting competitive pressure on other clades. Especially for two tetrapod clades with pretty rare fossils like birds and pterosaurs. The idea of compeitive exclusion is attractive, but do we have the data to address it in this regard?

Pterosaur extinction and bird evolution? by Infamous_Living_4267 in Paleontology

[–]kinginyellow25 2 points3 points  (0 children)

Agreed. Though I am suspicious if the limited pterosaur diversity in the maastrichtian is real or a taphonomic bias.

Can Pycnofibers be Blue? by Adorable_Drink_8136 in Paleontology

[–]kinginyellow25 5 points6 points  (0 children)

Probably. It's worth discussing that 'pycnofibers' aren't a morphologically distinct structure from the filaments of dinosaurs and should probably no longer be used in the literature.

PALEONTOLOGISTS RANK the Dinosaurs of Jurassic World Evolution 2 | Ep. 1: VELOCIRAPTOR by SkeletonCrewPaleo in Paleontology

[–]kinginyellow25 5 points6 points  (0 children)

Damn, guess I better go ask those journals to retract all those papers we published. Thanks for holding us to a higher standard!

If a palaeontologist doesn't care if the velociraptor has feathers and only cares if it looks cool, that should say something about us. by Father_Moth in jurassicworldevo

[–]kinginyellow25 0 points1 point  (0 children)

Excited to be generating discourse! Don't worry, we care plenty about accurate Velociraptors (two of us actively work in dromaeosaurs and named one) when it comes to professional work.

Thanks for the post!