SQUIDTOONS

Flamingo tongue snails at Florida Keys National Marine Sanctuary are fashion icons. 

They wore leopard print before it was trendy! 

The patterns themselves aren’t actually on the snail’s shell. Instead, the snail covers its white shell with a live tissue, which bears its distinctive color and markings. 

FOSSIL BRAINCASE AND THE ORIGIN OF GHOST SHARKS (WHO ARE NOT REALLY SHARKS)

The evolutionary origins of chimaeras -cartilaginous fishes known informally as ghost sharks- are now clearer thanks to the data provided of a computed tomography analysis of Dwykaselachus, an enigmatic chondrichthyan braincase from the ~280 million year old Karoo sediments of South Africa.

Despite their popular name, ghost sharks aren’t sharks in fact are related to sharks and rays, which also have cartilaginous bodies. 

At first place, externally the fossil was supposed to be a symmoriid shark, a group of 300 million-year-old sharks. Internally, the morphology exhibits otherwise characteristically chimaeroid specializations, including the otic labyrinth arrangement and the brain space configuration relative to exceptionally large orbits. Surprisingly the braincase preserves details about the brain shape, the paths of major cranial nerves and the anatomy of the inner ear.

These results have important implications for our view of modern of chimaera origins, add robust proof the phylogeny evolution of this group and shed new lights on the chondrichthyan response to the extinction at the end of the Devonian period.

lllustration:  Reconstruction of Dwykaselachus oosthuizeni by Kristen Tietjen.

Reference: Coates et al. 2017.  A symmoriiform chondrichthyan braincase and the origin of chimaeroid fishes. Nature.

Monday motivation?

Ocean planet

The animals of the deep ocean are a bit strange looking, to say the very least. Many of them resemble slimy blobs (including the aptly-named blobfish, which has been awarded the title of the world’s ugliest animal [I, for one, think it’s kind of cute]). We can’t judge the blobfish, and other deep-sea creatures based on their appearances, though. Why? To live where they do, they have to look like this just to survive.

School of eels in garnet.

These surface reaching etch pits reveal where the metamorphic fluids of its birth ate into weak points in the gem’s crystal structure.

Loz

Striped pyjama squid slumber party! You can visit these cephalopod hatchlings in our Tentacles special exhibition.