The Official Feathered Dinosaur Shitstorm Thread

[Donward]

Dagnabbit, my dinosaurs are sluggish, giant green lizards that are cold blooded and have extra brains in their rear ends because their pea-brain is too slow to operate! If you don't want them to be "terrible lizards" then give them a different name other than "dinosaur"!!!

[Sturgeon]

So, now we've established dinosaurs had feathers, how about thermoregulation?

 

*ducks for cover*

 

I had heard somewhere that crocs are most likely secondarily cold blooded. Which does imply dinosaurs were endothermic, along with pretty much all the archosaurs.

It would be difficult to imagine pterosaurs and early birds flying around with an ectothermic metabolism.

[xthetenth]

Dagnabbit, my dinosaurs are sluggish, giant green lizards that are cold blooded and have extra brains in their rear ends because their pea-brain is too slow to operate! If you don't want them to be "terrible lizards" then give them a different name other than "dinosaur"!!!

 

But the dinosaur is a noble beast of burden:

 

 

I've got to say the biology talk was really cool. The results of the simple mechanism are really neat. I wish I knew enough to come up with a really awkward question about the way the concept of species doesn't really map neatly onto the way morphology actually works in practice.

[Collimatrix]

So, now we've established dinosaurs had feathers, how about thermoregulation?

 

*ducks for cover*

 

It would be really weird for them to have insulation and lack an elevated metabolism.

 

If you don't have a high enough metabolic rate to warm your own flesh up, what's the point of having insulative feathers?  They'll just block the precious sunlight from warming your flesh!

[Toxn]

Don't forget sutface area to volume.

From what I remember from tetrapod zoology, it is entirely possible to have a hella slow metabolism and be in danger of overheating once you get large enough. At that point, feathers become useful as a way of insulating yourself from external heat sources which would make the problem worse.

[Donward]

Relevant given the OP is about dinosaur movies.

https://m.youtube.com/watch?v=VwtvEQAdLBQ

And as always, all old movie trailers had spoilers.

"Valley of Gwangi" (1969) is my favorite high concept dinosaur flick pitting an allosaurus against Winchester toting cowboys. Per the Wikipedia article, the stop-motion special effects were done by Ray Harryhausen, who learned his craft from special effect genius Willis O'Brien master of the original 1933 "King Kong".

If you're looking for the men responsible for cementing what dinosaurs "should" look like on the silver screen, it's these two.

http://en.m.wikipedia.org/wiki/The_Valley_of_Gwangi

[Sturgeon]

Relevant given the OP is about dinosaur movies.

https://m.youtube.com/watch?v=VwtvEQAdLBQ

And as always, all old movie trailers had spoilers.

"Valley of Gwangi" (1969) is my favorite high concept dinosaur flick pitting an allosaurus against Winchester toting cowboys. Per the Wikipedia article, the stop-motion special effects were done by Ray Harryhausen, who learned his craft from special effect genius Willis O'Brien master of the original 1933 "King Kong".

If you're looking for the men responsible for cementing what dinosaurs "should" look like on the silver screen, it's these two.

http://en.m.wikipedia.org/wiki/The_Valley_of_Gwangi

 

Harryhausen has achieved the rare distinction of being a favorite of both movie-makers and paleontologists. A lot of people will argue it was Jurassic Park that brought dinosaurs to life for the first time; they clearly have never seen Valley of Gwangi.

[Donward]

They seem hokey today but back then, Harryhausen was state-of-art. How else can you make Sinbad the Sailor fight skeletons or Perseus slay a Kraken and Medusa. When special effects were needed it had to be for a damn good reason or else the studio heads would can the film. Now any drug-addled director snorting blow off a stripper's ass can add any stupid thing he wants with CGI.

King Kong vs T-Rex (1933)

https://m.youtube.com/watch?v=uYWSOzFMZjg

There is more subtlety and complexity in that one scene than Michael Bay's entire film catalog.

[Toxn]

It helps that figurines and Claymation have lots of detail and so tend to hold up well. As compared to CGI, which tends to look progressively worse as time goes by...

[Collimatrix]

Don't forget sutface area to volume.

From what I remember from tetrapod zoology, it is entirely possible to have a hella slow metabolism and be in danger of overheating once you get large enough. At that point, feathers become useful as a way of insulating yourself from external heat sources which would make the problem worse.

 

Calorie consumption doesn't scale linearly with body mass.  It's approximately a 3/4 exponential curve.

 

From what I've read, very large animals like elephants are actually less prone to overheating than smaller ones in similar environments like gazelles because they have more thermal mass, and are generating less heat relative to that thermal mass.  They've also got far less surface area for the sun to shine on relative to body mass, so that's less of a problem too.

 

Of course, elephants cheat by having huge ears.

[Walter_Sobchak]

I decided to venture outside the tank related parts of this forum.  I felt lost for a while, I cannot speak with any authority on anything relating to dinosaurs.  Thankfully Donward mentioned Harryhausen.  Films are something I know about.  Everyone should watch the Seven Voyages of Sinbad, it's a classic.  As to dinosaurs, I figure they are a lot like my chickens.  I have seven of them and they are mean, stupid  creatures that will eat just about anything.  But, they give me eggs and they are fun to watch. 

[Donward]

My family raised chickens, about 80 at one point. The Buff Orphingtons, Black Sexlinks, and Barred Plymouth Rocks had generally mild dispositions. The Silver-laced Wyandotts were murderous rapists whom we quickly "retired". Since we raised them from chicks, a handful of them developed decent personalities, including one Black Sexlink who bonded to my little brother. Her name was simply "James' Chicken" and she'd knock on the back door of our house so she could lay her egg each morning in the laundry room. She loved to be picked up and petted, particularly by my little brother. The funny thing is she was a jealous woman and whenever James picked up another chicken, she'd beat the bird up once he set it down.

 

At the end of the day, she was still just a chicken but I'd like to think that she had a little proto-soul and she was certainly more human than many bipedal individuals I've met.

[Sturgeon]

I also raised chickens as a lad. I found them mean, stupid, dirty, murderous, rapey, suicidal, wholly unsuited to independent living, and cuddly.

[Donward]

Our Buff Orphington roosters were gregarious and brave, sacrificing themselves to protect their hens from hawks, eagles and coyotes. Sadly, one died after being ganged up on by a few of the aforementioned Wyondott cockerels. Another sacrificed himself fighting off a coyote.

 

The hens weren't terribly intelligent, admittedly. As another animal story, our farm cat Tom (not the most original name for a black tomcat) would help us herd the chickens into the chicken yard at the end of the day because he knew that the sooner that job was done, the sooner he'd get to go into the house for milk and warmth.

[Xlucine]

http://www.bbc.co.uk/news/science-environment-32205289

BBC: Brontosaurus dino name is revived

 

The iconic name Brontosaurus, once used to describe a family of huge dinosaurs, has been resurrected after being killed off more than a century ago.

[Oedipus Wreckx-n-Effect]

Evolution works by random mutations of DNA getting borked by transcription errors, ionizing radiation and teratogenic chemicals in such a manner that the borked DNA actually does something useful.

 

The odds of feathers evolving twice are astronomical.

That's a vast oversimplification, and even at that you left out a couple pretty important factors. 

 

 

And to the topic at hand, some dinosaurs had feathers.  Some did not. To make broad claims over millions of years, in a greatly changing climate and ecosystem, would be silly. 

 

They had as many feathers as they needed to survive.  They were as colorful as required for their niche. Dinosaurs aren't some mythical set of unicorns that defy all known population genetics knowledge. 

[Collimatrix]

That's a vast oversimplification, and even at that you left out a couple pretty important factors. 

 

 

And to the topic at hand, some dinosaurs had feathers.  Some did not. To make broad claims over millions of years, in a greatly changing climate and ecosystem, would be silly. 

 

They had as many feathers as they needed to survive.  They were as colorful as required for their niche. Dinosaurs aren't some mythical set of unicorns that defy all known population genetics knowledge. 

 

I think we linked it earlier, but new finds are showing that ornithiscians had feathers.  The odds that feathers evolved twice are so low as to basically be negligible, so we can conclude that all dinosaurs descended from the last common ancestor of saurischians and ornithiscians had feathers (or only lost them secondarily).  In other words, it's a synapomorphy.

[Donward]

I think we linked it earlier, but new finds are showing that ornithiscians had feathers. The odds that feathers evolved twice are so low as to basically be negligible, so we can conclude that all dinosaurs descended from the last common ancestor of saurischians and ornithiscians had feathers (or only lost them secondarily). In other words, it's a synapomorphy.

I'm not necessarily disputing anything. But we have whales, dolphins and seals whose ancestors left the oceans, grew lungs, said fuck it, and went back into the ocean. This is very much an over simplification. But it seems critters will evolve as many times as they see fit.

[Priory_of_Sion]

http://www.bbc.co.uk/news/science-environment-32205289

There is a similar debate going on between whether Torosaurus and Triceratops are the same species or not. From what I've seen, the different species hypothesis carries more weight. 

[Collimatrix]

Yes, cetaceans, pinnipeds, sirenians, and desmostylians all evolved to become ocean-going, but they did so in different (albeit similar) ways by a different suit of analogous, but not homologous mutations.

 

It's an example of convergence, like how thylacines look like wolves, but aren't.  A seal and a whale are under similar selective pressures.  They both live in the water, so they both must be streamlined.  They both have to be able to steer themselves in water, so both of them have modified forelimbs that act as flippers.  Both of them have to be able to hold their breath, so they have similar (but not identical) mutations to their myoglobin, which allows them to store enormous amounts of oxygen in special muscle tissue.

 

But there are differences too.  Both whales and seals have to propel themselves in water, but where sea lions have four sets of propulsive flippers and seals can undulate their entire bodies for propulsion, whales have lost their rear set of legs entirely and have large, fleshy flukes growing from their elongated tails.  Baleen whales and crabeater seals both strain water for krill, but baleen whales use modified hair while crabeater seals have heavily modified teeth.

 

So, similar, analogous mutations can and do evolve all the time.  Homologous mutations basically don't ever evolve twice, unless the phenotype in question is something that can be achieved by a very simple mutation that is likely to happen more than once.  The capacity for parthenogenesis in cnemidophorus/aspidoscelis (lesbian clone lizards), for instance, appears to arise readily from hybridization.  In the wild, this probably happened more than once.

 

But changing a scale into a feather requires more than one mutation.  A feather is quite different from a scale, even though, ontologically speaking they spring from the same tissue and use a modified version of the scale-making molecular machinery.  That simply will not happen twice exactly the same way.

 

Now, it could be that the hollow, keratinous structures found in pterosaurs, sauriscian dinosaurs and ornithiscian dinosaurs aren't exactly the same, and fossilized remains are simply too crudely preserved for the very subtle differences that indicate that they were independent adaptations to show.  If feathers are synapomorphic for avemetatarsalia (and I think that's the most parsimonious explanation), then the feathers one would expect to see outside of the most derived theropods would be hard to tell apart if they are analogous but not homologous.  It would take some really exceptional specimens to tell for sure.  So, we're stuck with indirect evidence, which so far has kept pointing to these things being symplesiomorphic.  They've showed up not only in ornithiscians, but in two groups (one very derived and the other very basal), they've showed up across theropoda, and they've showed up in pterosaurs.  The only major group of dinosaurs that there's no direct evidence for integument in is sauropods, and they weren't exactly common around the environments that readily preserved feathers in fossils.

 

An extremely well-preserved prosauropod would be terribly helpful, but unfortunately, the Solnhofen and Jehol deposits are both too geologically late to have any prosauropods.

[Collimatrix]

There is a similar debate going on between whether Torosaurus and Triceratops are the same species or not. From what I've seen, the different species hypothesis carries more weight. 

 

Sinking triceratops into torosaurus is a pretty weak hypothesis IMO.  It doesn't seem to have gotten much support.

 

For one thing, triceratops fossils are found like, 10:1 to torosaurus.  Now, mother nature is one freaky bitch, but what in the hell kind of weird mortality pattern kills off 90% of the members of a genus when they're subadults?  We're not talking juvenile or hatchling mortality here; nature loves killing off children.  We're talking teenagers; I don't know if triceratops fossils have been checked for medullary bone or other indications of sexual maturity, but I recall reading that the majority of them appear to be osteologically mature.  What the hell?  That would be really weird.

[Donward]

That is interesting about the Triceratops versus the Torosaurus. If they were the same species (which to my untrained eye they seem different) I guess it could be like an elk dropping its antlers in the spring. Or the physiological changes salmon undergo during osmoregulation when they leave salt water and enter fresh water. 

[Sturgeon]

I hate to be the awful pendant who points this out, but deer do not shed bony structures during the spring and then grow back huge sections of bone in the fall.

Under the current definition of "species" I feel pretty confident in saying that one cannot conclude anything but that Torosaurus and Triceratops were different species, given all the evidence.

[Donward]

Yes. You are being a pedant. I was using it as an analogy that was easily recognizable where deer and elk shed antlers which look and feel "bony" and grow them back by the fall. It's occurs yearly.

 

Whereas salmon will undergo a metamorphosis once in their life and an adult "spawned out" sockeye, chum, chinook, pink or coho salmon will look remarkably different than an adult salmon who is still in the salt water. 

 

I was using modern analogs to propose a what-if for the Triceratops vs Torosaurus theory which I disagree with by the way. They look to me to be two separate species.

[Sturgeon]

Yes. You are being a pedant. I was using it as an analogy that was easily recognizable where deer and elk shed antlers which look and feel "bony" and grow them back by the fall. It's occurs yearly.

 

Whereas salmon will undergo a metamorphosis once in their life and an adult "spawned out" sockeye, chum, chinook, pink or coho salmon will look remarkably different than an adult salmon who is still in the salt water. 

 

I was using modern analogs to propose a what-if for the Triceratops vs Torosaurus theory which I disagree with by the way. They look to me to be two separate species.

 

If it were true that they were the same species, something very weird would have to be going on, certainly. I mean, look at the skulls: