Here’s the organism (well, sort of. . . .)!

Did you guess what organism made the pattern below, found on a recent dive around the hydrothermal vents off Tonga?

Here’s the answer in the second tweet:

How big is that thing? The laser beam images are 10 cm (about 4 inches apart): The paper from which this comes (below) adds, “Note the shield-shaped elevation, marginal elevated rim and mote, and color (pale pink) of the area of the pattern compared with the surrounding veneer of gray calcareous lutite (image courtesy The Stephen Low Company).” You can find thousands of these things on the wall of the mid-Atlantic Ridge.

The pattern is similar to that described in a 2009 paper in Deep Sea Research (click on screenshot to go there):

It’s called a “living fossil” because the patterns are nearly identical to those found in ocean sediment cores from about 50 million years ago. That doesn’t mean, of course, that the organism that made (or left) this pattern is the same as the ancient one, for it may be not a fossil but a burrow.

But what IS the organism involved? The paper above doesn’t say, because they haven’t recovered an organism from whatever makes this pattern. DNA sequencing of material recovered from the holes shows genetic material from foraminiferans, protists that probably settled in the holes rather than making them.

When the holes are injected with resin underwater, and then the cast recovered, it looks like this (caption from paper):

Fig. 8. Photo of plasticine reconstruction (3-D) of the modern P. nodosum pattern based on observation of the hexagonal pattern of holes at the sediment–water interface and vertical shafts connecting with an underlying horizontal hexagonal network of tunnels or tubes (model and photo by Hans Luginsland).

The raised nature of the pattern as well as the rim can, according to the authors’ models, enhance water flow over the openings, suggesting that either this is a burrow of some sort or the 3-D remains of an organism that filtered microbes out of the water.  The authors suggest this could be a remnant of one of two types of organisms:

1.) Xenophyophores: Giant single-celled foraminifera that have multiple nuclei and form a “test”, a hard skeleton made from minerals extracted from seawater.

2.) The remains of a sponge. As the authors say:

Alternatively, the modern form is the compressed body of a hexactinellid sponge adapted to an unconsolidated sedimentary substrate (Rona and Merrill, 1978). If this interpretation is correct, then the fossil form is a body rather than trace fossil.

These sponges have hard parts as they contain spicules (small bits of the body) made of silicon.

Alternatively, it could be something else. The authors don’t consider that it might be burrows of a worm, but this site suggests that:

The short answer is, “We have no fricking idea.” There are many mysteries on the ocean floor.

14 Comments

  1. Posted December 8, 2017 at 12:31 pm | Permalink

    Oh man, I had seen this maybe a year ago. I am going to speculate it is the pattern from the excurent siphons of a colonial tunicate. Just to guess something. The foraminiferan DNA could be from tunicate poo.

  2. Posted December 8, 2017 at 12:56 pm | Permalink

    Reblogged this on The Logical Place.

  3. Stephen Barnard
    Posted December 8, 2017 at 1:05 pm | Permalink

    We can rule out Bigfoot.

    • busterggi
      Posted December 8, 2017 at 1:52 pm | Permalink

      We can NEVER rule out bigfoot!

      • Stephen Barnard
        Posted December 8, 2017 at 8:10 pm | Permalink

        The evidence against bigfoot seems pretty overwhelming in this case, considering that the samples are found on the deep-sea floor. But what you say is true — can’t prove a negative and all that. Maybe this bigfoot perished in the Flood.

  4. Liz
    Posted December 8, 2017 at 1:08 pm | Permalink

    I was also thinking archaeon but thought that would be way too small. So neat to think about how we’ve come all this way. When I was younger, I used to think that creationists were branching off into a new species. It was actually really not too long ago. I still wonder about that and have read a few things on here about the differences in races and populations of people. I didn’t really understand the first time because I sort of skimmed and really need to read a few times. I think it’s fascinating. I think instead of planning on going to the moon, we should have volunteers quarantine themselves on Antarctica. We could go back later (much later) and check to see if a new species is there.

    • Liz
      Posted December 8, 2017 at 1:25 pm | Permalink

      Sorry. I meant Mars.

    • Michael Fisher
      Posted December 8, 2017 at 7:49 pm | Permalink

      Would these generations of ‘Antarcticans’ have knowledge of the rest of human society? I think I’d be annoyed if I was born in an environment harsher than a Siberian Gulag & not permitted to leave 🙂

      • Liz
        Posted December 11, 2017 at 9:11 am | Permalink

        Good question. I have no idea. Maybe. It’s more hypothetical than practical.

  5. Posted December 8, 2017 at 1:22 pm | Permalink

    Underwater acid bees.

  6. Dave
    Posted December 8, 2017 at 1:43 pm | Permalink

    I would come down strongly in favour of this being the surface trace of a giant protist of some kind, either a foraminiferan or xenophyophore. The organism itself would consist of a network of cytoplasmic threads (probably multinucleate) ramifying just below the sediment surface, with vertical extensions to the sediment-water interface.

    I favour this identification on the basis of professional experience. I’ve worked in deep-sea benthic biology for nearly 20 years and I’ve done a lot of work on identifying and quantifying features (“Lebensspuren”)visible on seabed photos. Also, where I work on the west coast of Scotland, there is a shallow-water giant foraminiferan (described by a colleague of mine and named Toxisarcon alba). This species produces a small raised “bump” on the mud surface, studded with small holes and looking like the top of a pepper pot. The overall appearance is very similar to the mid-Atlantic Ridge photo shown here.

    I’ve also done a lot of work on worm burrows and I would tend to rule those out as an explanation. I don’t know of any burrowing worm, in shallow or deep water, which would produce a trace as regular as this.

    • gravelinspector-Aidan
      Posted December 9, 2017 at 11:19 am | Permalink

      I don’t know of any burrowing worm, in shallow or deep water, which would produce a trace as regular as this.

      The almost-regularity gets me too. It’s not a simple trigonal grid – about 1 in 4 of the nodes of such a grid appear unoccupied. But the edges of the gridded area don’t follow the grid, or even it’s symmetry elements.
      Really needs sampling. I can think of a way to build a Mk.1 sampler, but there’s probably something suitable on the shelf already. Just unfortunate that it seems to have been on the shelf and not on the ROV this time around.

  7. lkr
    Posted December 8, 2017 at 7:51 pm | Permalink

    Davey Jones’ cribbage board

  8. ThyroidPlanet
    Posted December 8, 2017 at 8:45 pm | Permalink

    Very interesting!

    This is probably mentioned but I see that it looks globally hexagonal


Post a Comment

Required fields are marked *
*
*

%d bloggers like this: