An ongoing dinosaur encyclopedia. I also run A Pterosaur A Day.


A Dinosaur A Day

A Field Guide To Dinosaurs

I heard about the crocodile theory. I don't think it's too implausible. Certainly odd to think about but I don't think it'd be impossible given some of the traits crocodiles and early archosaurs had. Sincerely, Anonymous

It’s not implausible but I’m actually a sort of expert on homeothermy in avians 

http://www.oeb.harvard.edu/faculty/edwards/people/postdocs/organ.htm

Chris Organ is my “science crush” if you will and he published a paper discussing avian genomes

Using bone cell size they actually managed to estimate the size of dinosaur genomes based on a regression model formed from bird bone cell size to genome size ratio 

Believe it or not most theropod dinosaurs and birds have small genomes (except oviraptors like what the hell) while non-theropods and crocodiles have a wide range of genome sizes

Pterosaurs also had small genomes they found in a later study and so do bats!

And actually this small genome allowed birds to have smaller cells which actually helped contribute to flight

But it’s been hypothesized that small genomes allowed for homeothermy in birds because the small cells made it easier to transport enough oxygen to the body to keep up a high metabolism and thus keep a constant body temp 

This same thing occurred in mammals except they just lost the nucleus of their blood cells so the actual genome remained large which is why only bats can fly as opposed to all mammals 

So while archosaurs might have had homeothermy and then lost it it seems strange that both crocs and non-theropod dinos lost it? 

But it’s also very possible that genome size and homeothermy aren’t required together but the smaller genome just made homeothermy easier 

The jury’s still out in my opinion 

And all this just makes me wish for dinosaur genomes to analyze that  much harder 

For the record

In all the feather excitement today I kiiiiinda ran out of time to do a dino

Consider Kulindadromeus zabaikalicus to be today’s dino

Check it out » A new fossil suggests 'all dinosaurs' may have had feathers

lythronax-argestes-the-gore-king:

raptorcivilization:

lythronax-argestes-the-gore-king:

assuming-dinosaur:

skeletaldrawing:

Funny that this would break embargo mere minutes after my response to a question about dinofuzz. Definitely strengthens the idea that dinosaurs (and maybe the common ancestor of pterosaurs and dinosaurs) were primitively fuzzy.

eeeeeeEEEEEEEEEEEEEEeeeeeeEEEEE!!!!!!!!

Guys, ornithischians are cool again!

On a more serious note, the wide scales on top of the tail remind me a bit of Scleromochlus—does anyone better informed than I know if Scleromochlus is still thought to have transversely wide scutes on its lower back?

Wow, six types of integumentary structure in one animal. Imagine what more we still have to learn about dinosaur integument—heck, Kulindadromeus* is practically an “anything goes” signal for reconstructions of anything except for well-bracketed stuff like hadrosaurids and pennaraptors.  Now we just need a couple more basal taxa like coelophysids and silesaurids to be found with feathers and we can be certain.

*finally, I’m sure I’m getting the vowels right

Wow, more compelling evidence for integumentary structures in dinosaurs! We could see a variety of such fuzzes in various ornithschians and maybe also trace it back to dinosauriformes!

I believe that fuzziness is inherent in all of Archosauria. All these dinosaurs with feathers, pterosaur pycnofibers, and crocodilians apparently have the feather gene. As well, there is some evidence for the archosaurian ancestor being warm-blooded, and crocodilians simply re-evolved cold-bloodedness.

That is the best theory I’ve ever heard and it’s very plausible! Thank you
raptorcivilization
, I will now draw all virtually every archosaur with some kind of fuzz.

(via dinostuck)

Something I wanted to add/ask about your "feathered until proven otherwise" thing. I read an article a while back that said/suggested that the scales found in birds are more akin to modified feathers that typical reptile scales. If this is true, then couldn't it be possible that the scales of dinosaurs could more accurately be called scale-like feathers rather than just straight scales? Sincerely, Anonymous

That is true! I never even thought of that!

It’s even been proposed that the ancestral archosaur was warm blooded and crocs re-evolved cold bloodedness 

But actually that’s a little more controversial even for me if you’d like mto say more 

@dnshantz replied to your post: Sung to the tune of Everything is Awes…

I gave that article a quick look. Wouldn’t feathers still be primarily a theropod thing? I mean, we have that mummified hadrosaur with the preserved skin and organs and whatnot. I’m super on board for more feathered dinos, but everything?

I mean okay

I’m primary an evolutionary genomicist (or that’s the ideal okay so) 

According to cladistics if two separate but closely related groups share a trait (synapomorphy) then it stands to reason (occam’s razor) that their last common ancestor had the trait, it’s certainly more likely than both groups evolved it themselves 

Like wings evolved separately in birds and pterosaurs but you can tell that they did - the wings are structured much differently. 

But the feather gene has been found in crocodiles. The same feather gene. And pterosaur pycnofibres were probably protofeather integuments too. 

While many dinosaurs probably lost their integuments - like Carnotaurus, for which we’ve found skin fossils, as well as crocs - I think we need to change our initial assumption

Instead of assuming all dinosaurs were scaly until proven otherwise 

From a biological perspective, we should assume they were feathered… until proven otherwise 

lythronax-argestes-the-gore-king:

Sneak peek at an upcoming project!

Coming tomorrow: Baby. Dinosaur. Tracks.

westerndigs:

Attention, friends on the paleo side. I have just three words for you regarding tomorrow’s story: Baby. Dinosaur. Tracks.

(via crazedcrocgirl)

Sung to the tune of Everything is Awesome: 

EVERYTHING HAD FEATHERS 

EVERYTHING HAD FLUFF IN THE MESOZOIC 

EVERYTHING HAD FEATHERS 

YOU CAN SUCK IT BANDITS 

Check it out » A new fossil suggests 'all dinosaurs' may have had feathers

dinodorks:

dinodorks:

drawingdinosaurs:

lythronax-argestes-the-gore-king:

skeletaldrawing:

Funny that this would break embargo mere minutes after my response to a question about dinofuzz. Definitely strengthens the idea that dinosaurs (and maybe the common ancestor of pterosaurs and dinosaurs) were primitively fuzzy.

Whoa, that was fast.

Kulindadromeus is an ornithopod, correct? Just fuzzy?

The paper’s abstract describes it as a “basal neornithischian”, so it’s not quite as derived as ornithopods.

!!!!!!!!
- Mod Rainfrogs

I KNEW IT

Confirmed decisions about the channel so far: 

1. It will feature many, many puns 

2. Firefly will be quoted

Check it out » What would you like from a YouTube Channel from me? Survey

dinostuck:

Friendly reminder that this is a thing I’d like you all to fill out

(via a-dinosaur-a-day)

Fukuiraptor kitadeniensis

Source: http://www005.upp.so-net.ne.jp/JurassicGallery/page4.htm

NameFukuiraptor kitadeniensis

Name Meaning: Fukui thief

First Described: 2000

Described By: Azuma & Currie

ClassificationDinosauria, Saurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Carnosauria, Allosauroidea, Allosauria, Neovenatoridae 

Fukuiraptor, besides having a somewhat amusing name, is a fairly enigmatic dinosaur. It was found in the Kitadani Formation of Fukui Prefecture, Honshu Island, Japan. It lived in the Barremian stage of the early Cretaceous, about 128 million years ago. it was not big, it was only 4.2 meters long, but this size might be the size of a juvenile. It is only known from a single specimen and when it was discovered one of its hand claws was put on the foot as a killer claw, giving it its raptor name, when it is not a maniraptor in the slightest. It is also possible that it was a tyrannosauroid, making it a coelurosaur rather than a carnosaur. Thus the actual classification is up for debate. 

Sources:

http://en.wikipedia.org/wiki/Fukuiraptor

http://www.prehistoric-wildlife.com/species/f/fukuiraptor.html

Shout out goes to billy-bumblr!

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dinostuck:

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Tyrannotitan chubutensis

Source: http://dinosaurs.wikia.com/wiki/File:Tyrannotitan_by_L34ndr0.jpg

NameTyrannotitan chubutensis

Name Meaning: Chubut Tyrant titan

First Described: 2005

Described By: Novas et al. 

ClassificationDinosauria, Saurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Carnosauria, Allosauroidea, Allosauria, Carcharodontosauria, Carcharodontosauridae, Giganotosaurini 

As all of its close relatives in GiganotosauriniTyrannotitan was an impressively large and terrifying carnosaur. It was also from Argentina, found in the Cerro Barcino Formation in Chubut Province, Argentina. It lived in the Aptian stage of the Early Cretaceous, about 118 million years ago. However not much is known about it because only a limited amount of literature has been released about the animal. It was estimated to be 12.2 meters long and close to 4 meters high. It had teeth that were less blade like than its relatives, making them seem less developed and lacks certain bone features that its cousins have. It has a much less developed scapulocoracoid than Giganotosaurus. It looks vaguely tyrannosaurus like due to the curve of its acromion, but don’t mistake it for a tyrannosaurid - it is decidedly not. 

Source: http://www.jurassicworld-movie.com/community/forums/topic/30875

Tyrannotitan’s denticles on the teeth were divided into two by a groove, which would have formed an additional cutting surface for the animal. This was not a trait that carried on, however. It, like its relatives, stripped flesh from its kill rather than crunching bones. It is possible it is not actually a separate genus, but until more material is found, that is up for debate. 

Sources: 

http://www.prehistoric-wildlife.com/species/t/tyrannotitan.html

http://en.wikipedia.org/wiki/Tyrannotitan

Shout out goes to joroan8!