I have a new guest post up today over at the Scientific American Guest Blog on a newly discovered cache of the earliest known big multicellular life — and how some of it (but definitely not all) is startlingly like stuff alive today, 600 million years later. Go check it out!

Fractofusus, vintage 600 million years ago give or take. Salp ancestors? Shark tooth kebabs? Early Surf-board Peeps(TM)? If you can figure out what the heck this is, you get a gold star -- and a paper in Nature! Photo by Dr. S.B. Misra

No time for a long post tonight or likely over the weekend, but just wanted to give you guys a heads-up on a don’t-miss article. The grand story of life on Earth has a rather extended bacterial prologue (or a fairly short multicellular epilogue, depending on how you look at it). In fact, the story of bacteria is almost the story of the entire book.  Multicellular life only came along in the last 600 million years or so, and life is posited to have existed on Earth almost since its formation 4.6 <pinky to mouth>billion</pinky to mouth> years ago, and certainly since at least 4 billion years ago (doing the math, that means bacteria have been around 8 times longer than us “higher” organisms).

Anywho, one of the Big Questions is why it took so long for multicellular life to show up, and once it did, why the first draft was *so frickin’ weird* compared to what exists today. The Ediacaran fauna is that first draft, and it bears little resemblance to the life that came afterward in the Cambrian Explosion. You’ve heard me mention the Ediacaran fauna before, notably on my visit to the Sant Ocean Hall last fall in which I was utterly ecstatic to get to see some of the original Ediacaran fossils in person. This article in the New York Times tackles scientists’ current thinking on the Big Questions — and has a lovely slide show  that helps explain why I get so excited about Ediacara (only disadvantage: no scale bars. Some of these guys are way smaller than photos would leave you to believe — and some are larger).

Even I was stunned to discover a few fossils in the show I’d never seen before — particularly Fractofusus, above. I had a big WOW moment when I saw it. By far, it is the most beautiful Ediacaran I’ve seen. It comes from an Ediacaran locality I hadn’t been aware of previously: the gloriously named “Mistaken Point” on the south shore of Newfoundland. The photo above doesn’t quite do justice to the photo in the NYT slideshow, so make sure you check it out.

What the heck was it? How was it making a living? What did it look like in real life? Was it brightly colored? Was it an evolutionary dead end or is it a secret ancestor of some totally common form today? If secret ancestor, was it of plant, animal, or “other”? If only, if only, if only I could climb in a phone booth time machine with Keanu and So-crates and take a peak in those early oceans(ok, that’s multicellularist. Late oceans.). That would be most excellent.

The sort of habitat our mystery creature lives in, and the submersible that has tried to find it. DSV Alvin sets a lander basket with tube cores on the bottom. Note the encroaching darkness. Think of yourself living in that environment -- a soft mud bottom, and nothing but miles and miles of cold, inky blackness, as far as the eye can't see. Credit: National Oceanic and Atmospheric Administration/Department of Commerce

There are a few creatures on Earth we knew as fossils before we met face to face. Take the coelacanth. Scientists were shocked to discover a very much alive specimen of this be-lobe-finned fish hauled from the depths off South Africa in 1938. Prior to the discovery of this bit of rather irrefutable evidence, scientists believed the fish went the way of the dinosaurs (literally) at the end of the Cretaceous, 65 million years prior. Although not the first, Paleodictyon is probably the only member of this fossils-first group that was briefly considered to be evidence of some sort of alien deep sea race (hellooooo, Abyss) before it was connected to its fossil ancestors, essentially unchanged after 500 million years.

According to the article, scientists have suggested the hexagonal tubes they have found may be bacteria farms, worm burrows (or both), or the trace fossils of decayed compressed sponges that have long ago been scavanged. The paper even suggests such a sponge may have ties to the Ediacaran fauna, a class of bizarre creatures that preceeded the Cambrian Explosion. There’s one other candidate for Paleodictyon‘s identiy: a xenophyophore. They are the subject for another blog post, but the short, short version is that they’re gigantic single-celled organisms big enough to fit in the palm of your hand, which (like slime molds!) are multinucleate and feed by engulfment using pseudopodia, and (unlike slime molds) inhabit casings they put together with odd things lying around, including (sometimes) their own feces. In spite of being startlingly obscure, these things are apparently quite abundant on certain parts of the ocean floor. Still, this possibility doesn’t quite seem to fit the bill as no xenophyophore crunchy bits have ever been found in the hexagonal holes.

What about you, readers? What do you think Paleodictyon nodosum is? If you think you know the answer, write it on the side of a Deep Flight Super Falcon High Performance Winged Submersible with carbon fiber pressure hull, dual cockpit flight controls, heads-up instrumentation, and laser “collision avoidance feeler beams”, and mail it to Jennifer Frazer, General Delivery, Boulder, CO 80301. Or put it in the comments below (boooo-ring!). Creative answers encouraged!