‼️‼️Triassic Life just opened @smnstuttgart.bsky.social‼️‼️

For all #Triassic fans, lovers of strange reptiles and the Dawn of the Modern World, this is an absolute MUST!

It also couldn't be more timely with our recent publication @nature.com of the wonder reptile #Mirasaura, which is now on display!

The Mirasaura appendages were clearly not made to glide or fly, and, since they did not contain any blood vessels, they weren't used for thermoregulation either. Instead, the crest was likely a #displayitem, probably used to impress mates and ward off competitors.

It's hard to overstate the importance of skin appendages (hair and feathers) and their importance for #mammal and #dinosaur (incl. bird) #evolution. They enabled warm-bloodedness by insulating the body, and are used for courtship, display, deterrence and (for feathers) flight.

But on a microstructural level, the story is different. Using #SEM imaging, we identified #melanosomes (melanin-bearing cells) and analysed their shape @ucc.ie. They turned out to be most similar to feathers among skin tissue types in amniotes.

However, the typical feather shape, including the central rachis, is formed through a complex branching process. In #Mirasaura, the appendages lack any branching but form solid sheets. This shows that structurally, feathers and the Mirasaura appendages formed independently.

It consists of appendages that grew vertically from the back of the animal, and which overlapped each other in a complex pattern forming the crest. Each appendage has a central ridge and a sheet on either side, superficially resembling feathers...

The unique morphology of drepanosaurs makes it tricky to assess their evolutionary position, although it's clear they don't belong to any modern reptile group.

We found that they split off before the origin of all modern reptiles, making their crest even more surprising!

We scanned the tiny Mirasaura skull (compressed to be <1 mm(!!) thin) using @esrf.fr synchrotron radiation. It reveals the most bird-like drepanosaur skull to date, with a mostly toothless snout, large forward-facing orbits, and a wide, dome-like skull roof for a sizeable brain

#Mirasaura and #Longisquama are #drepanosaurs. These tree-living specialists have bird-like skulls, prehensile tails, and grasping limbs. A typical Triassic weirdo, they perhaps vaguely resembled a pygmy anteater.

But it's fair to say, we just made drepanosaurs even weirder!

Mirasaura is similar to #Longisquama, a controversial Triassic reptile described in the 70s. Longisquama remained a mystery due to its poor preservation and it was used as an alternate bird "ancestor". With Mirasaura, we can now also finally put the Longisquama debate to rest.

Starting in 1935, #Mirasaura was excavated in Alsace, France by renowned private collector Louis #Grauvogel, after whom the species is named.

Following the transfer of the Grauvogel collection to the @smnstuttgart.bsky.social, further preparation of one fossil created a true 'wow' moment.

I am proud and grateful to present a dream project today in @nature.com www.nature.com/articles/s41...

Meet #Mirasaura grauvogeli, a #wonderreptilewith skin appendages that rival feathers and hairs, challenging our view of reptile #evolution🪶🦎

Having an absolutely wonderful time at #IVPP in Beijing, studying old and new fossil friends alike, including possibly the world's coolest jigsaw puzzle #Dinocephalosaurus #RealChineseDragon🐉🐉🐉🐉 #Tanysauria, together with Wang Wei, Adam Rytel, and Nick Fraser!