Beautiful

cannabineer

cannabineer

Ursus marijanus
Pad, please stop already with the honeys. I put specific language in the opening post directing the honeys to their proper threads. one of which is yours. I am still furious with you for killing the Noodz thread, despite my direct warnings. Show some consideration here, at least.

GWN, thank you for bringing it back.
I'll post some Beautiful later. I spent half an hour assembling a post celebrating one of my favorite awesomenesses yesterday, and when I hit Post, my Firefox folded up. Argbl.
 
cannabineer

cannabineer

Ursus marijanus
I want to gush today about a topic dear to me ... the earliest ecologies of multicellular critters we've teased from the record of the rocks thus far. The lonely crag, the true Olympus of Cambrian fossil sites is the Burgess Shale, a remarkably small outcrop that the great naturalist Charles Walcott literally stumbled upon in the early 20th century. It's in a fairlly inaccessible corner of the Canadian Rockies in easternmost British Columbia.

And it has an amazing level of preservation, including some soft-tissue fossils that allow resolution of subtle details like muscle blocks in proto-Chordata.

Here's the site with a found trilobite.



The tour begins with Pikaia, our putative ancestor. it's a very primitive chordate (vertebrates share the phylum Chordata with oddities such as salps and sea squirts) quite similar to today's lancelet, a tiny agnathous (jawless) fish distributed worldwide.


The lancelet.


Here is a Peripatus (a velvet worm), an onychophoran. Why am I showing a contemporary creature? To introduce perhaps the weirdest of the Burgess fauna.

Onychophorans look like a caterpillar/earthworm hybrid, but are actually a primitive waypoint on the way to spiders. The spectacular creature Hallucigenia has resisted classification, but is now considered to be an earliest onychophoran. Part of the confusion was a long and erudite debate at the highest levels of paleontology about the crucial question ... which side was up? Here's H. sparsa in the rock.

An early reconstruction of Hallucigenia showed it stilting about on long stiff spikes for legs.

This hypothesis has recently been turned upside down, and the tentacular bits are thought to be the legs, and the long spines are carried as a defense, foreshadowing stegosaurs.

But fret not, junior paleontologists! There remains room for discovery. A mighty question remains unanswered ... which end is forward?

I bring you now to the mid-Cambrian sea's sovereign badass. Anomalocaris (odd shrimp) was over a meter long and an obvious hunter. It had a circular mouth of plates ... this structure was found by itself and thought to be something jellyfishlike. Its segmented curling mustache of spiky grasping forelimbs was also initially thought to be a smaller, complete animal.
Here are its strange four-way jaws in a disc.

its forelimbs that look like shrimp themselves and drove the creature's naming ...

...and a reconstruction of the entire beast. It looks like half bug, half manta.



Wiwaxia is as weird as its name sounds. A possible early mollusc or echinoderm (to which sea urchins and starfish belong today) ...it puts me in mund of a computer mouse for masochists.
From this

they could reconstruct this.




I have saved my favorite for last ... Opabinia. This is a primitive arthropod/crustacean probably somewhat related to Anomalocaris, but it has some unique features. the five eyes are the second-coolest of these, but the mouthparts, which irresistibly remind me of monsters I saw depicted in saturday-morning cartoons, is the winner.
In the rock.

A reconstruction showing an imo unlikely freewater predation mode.


But with a mouth like that, it was probably the most feared predator of small tubular shells or burrows. Omg omg omg I would LOVE to have an aquarium of these!


cn
 
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