Panama Ruined Everything

So, what do you think about the great american interchange
— @rosemary-lalonde

As a giant fan of birds (as well as a fan of giant birds) I, for one, am personally offended by the Great American Interchange and would like to know who is claiming responsibility for Panama as I have a strongly-worded letter coming right for them

Photo from Richard Cowen

Photo from Richard Cowen

For those of you unaware of this absolute travesty, the Great American Interchange occurred ~2.5MYA when a land bridge (aka Central America) formed between North and South America, allowing a transfer of species between the two. For a brief period, everything was beautiful and both continents were overrun with phorusrhacids, the feathery incarnation of all of my hopes and dreams.

Photo from Wikimedia Commons

But then, like the jerks we are, mammals had to go and ruin everything by out-competing and eating all the giant flightless birds. Now all we’re left with are dogs and bears and a few weird marsupials and only two species of seriemas. U N B E L I E V A B L E

Photo from Project Noah

Photo from Project Noah

Fluffosaurus rex

Q: did t. rex’s have feathers? i’ve been getting conflicting answers
— Anonymous

I hate to have to tell you this, but the reason you are getting conflicting answers is because the answer itself is unresolved. But never fear, my friend, you came to the right place! I will gladly muddy the situation further by explaining why. No, no, don’t thank me. I am here to serve.

The main problem is that so far no large, fossilized skin impressions attributed to T. rex have been discovered, which is why we can’t say for certain if they were or were not covered in scales, feathers, or some ungodly mix of both.

Photo from SAURIAN

Photo from SAURIAN

Without direct evidence, reconstructions of T. rex are forced to rely on skin impressions and fossils from other dinosaurs, with the likelihood of similarities being based on how closely they’re related; whether or not the species is an ancestor or descendant of the tyrannosauroids; whether they are the same size, same environment, same niche… you get the idea. It’s complicated.

And we do have many skin impressions of dinosaurs that were definitively scaly. Stegosaurs, allosaurs, ankylosaurs and many other species have had soft tissue impressions found, all with scales. It is not completely unreasonable to say that T. rex could also have been entirely scaled.

Original photo from Getty Images

Original photo from Getty Images

Of course, this is all without taking into account Dilong and Yutyrannus. Dilong was a small, basal tyrannosaur - an ancestor to T. rex - and in 2004 a fossil was discovered with preserved filamentous protofeathers.

Photo from Xu et al 2004

Photo from Xu et al 2004

Then, in 2012, Yutyrannus huali was discovered, a tyrannosaur from the Early Cretaceous with definitive impressions of feathers. Also, much closer T. rex in both size and time.

Photo from Xu et al 2012

Photo from Xu et al 2012

At this point, even without significant soft tissue impressions from T. rex itself, it is becoming increasingly unlikely that T. rex was entirely scaled. It is surrounded on all sides, evolutionarily speaking, with feathery species of theropods. It is still possible, of course, since the feathers of its ancestors could have secondarily lost for any number of very valid reasons, but it is just as possible, if not more so, that it would have been covered in some kind of feathery integument.

Anyway, I hope this cleared absolutely nothing up for you, as it has for me. You’re welcome.