Posts Tagged ‘cephalopods’

Because we know we can’t be found

12 October 2011

In case you missed it, today marks the end of Cephalopod Awareness Day 2011. I cannot decide if it is comedy or tragedy that the cephalopod who garnered the most awareness this week is one that probably never existed. “Triassic Kraken” has already entered the hyper-meta phase: here is a reaction to the reaction to the reaction to the early “reporting” on the story.

But amidst the orgy of credulity, incredulity, joy, anguish, laughter and rage (and whatever this is supposed to be), it struck me that something was missing. I have seen loads of skeptical remarks from vert paleo types, and certainly we are well suited to critique the work, but it seems nobody thought to ask the opinions of those that have studied the middens left behind by living octopodes.

So I did.

I fired off a list of questions to two midden experts, Dr. Richard Ambrose and Dr. Jennifer Mather, both of whom have published multiple papers on the topic of octopus middens. Both were incredibly gracious in providing detailed and thoughtful replies within hours.

My interest here was not whether McMenamin’s scenario is realistic. Clearly it is, at best, wild and highly imaginative speculation.

But I was interested whether it might be feasible to identify octopus middens in the fossil record. How we might identify vertebrate victims of cephalopod predation? And, leaving aside the whole “self-portrait” thing, is it really feasible that a giant bathypelagic squid would be exhibiting behavior associated with shallow water octopods.

In short the answers seem to be: 1) “Probably” 2) “Hard to say” and 3) “No.”

Both Dr. Ambrose and Dr. Mather were kind enough to allow me to share their comments:

Probable example of an octopus bite mark on fossil bivalve shell from Harper 2002.

me: What are the prospects of successfully identifying octopus middens in the fossil record (i.e. are they permanent enough features that they would be likely to be buried by sediment, and would they be readily distinguishable from storm deposits)?

Richard Ambrose: I think middens could be discovered in the fossil record.  Depending on the species, octopuses may den at the same location for a considerable time (“considerable” being relative, since octopuses are semelparous and most species live only a few years at most; even the giant Pacific octopus probably lives only 5 years or so) and they would continue to deposit midden items as long as they occupied the site.  Moreover, good denning sites are often limited, so even once on octopus vacated the den site another would be likely to take up residence, further building up the midden.  When we are looking for middens while diving, we focus only on the recent midden items because these are whiter and more conspicuous, but I would not be surprised to see an accumulation of midden items over many years.

Of course, many midden items are dispersed by currents.  For example, we rarely find many crab exoskeletons because they are easily swept away by currents.  Depending on the location, even heavier items like clam and snail shells can be dispersed.  So for the middens to enter the fossil record, you would need some event, like dramatic sedimentation associated with a storm or perhaps an undersea slide, to preserve the items in place.  But this is not inconceivable, especially after a storm.  I do think they likely could be distinguished from storm deposits.  Although storms might deposit a concentration of shells in one area because of local topography, most items would be widespread over the storm-affected area.

Jennifer Mather: Prospects would probably be good, some but not all fossil remains get buried in soft sediment.  Distinguished from storm deposits would be possible.  First they might have drill and chip marks on the shells–chips on clams, drills on clams, snails and sometimes crustacean claws.  Drill holes of cephs are tiny, too and specifically placed (Marion Nixon did a lot on that).  Not all shells are drilled or chipped, though.  Second, they WOULD NOT be broken.  Cephs have partial digestion externally, they scrape and digest out the soft parts leaving a disarticulated set of crab shell pieces or empty clean mollusc shells. Shell collectors prize octopus middens. So a midden would have a nice complete collection of crab parts, for instance, and if it was in soft sediment and got buried quite quickly, it might get well preserved. I remember watching the ‘fate’ of the eight blue shells of one octopuses chiton meal.  They slipped down the pile and slowly got buried, when I exhumed the whole thing much later, the blue winged shells emerged one by one, very well preserved and with a drill hole in one valve.

me: Assuming vertebrate remains would not show the drill holes characteristic of shelled prey, what signs could we look for to indicate cephalopod predation?

RA: That’s true, only shells are likely to show indisputable evidence of octopus predation.  (Octopuses also “drill” crabs, but those would be quite perishable.)  For vertebrates, they would just eat the flesh.  There might be some dis-articulation, but the fish eaten by the octopuses I’ve kept in the lab were not pulled apart, so I don’t know how common that would be.  So it would be very hard to find marks or other characteristics that would indicate consumption by a cephalopod.  There might be scrapes from the beak on bones, but I’ve never looked at/for these and I would think they would not be very distinctive.

Octopus midden from Flickr user Steven Severinghaus - Creative Commons 2.0

me: How widely distributed is midden building behavior among octopus species? Has it evolved more than once? Is it known from deep sea or pelagic species?

RA: This is really the key issue, I think.  Midden building is very common among octopuses, but it seems to me that it is most likely a simple consequence of their denning behavior and the fact that they often (but not always) bring food back to their den for consumption.  Hence, they discard prey items outside of their dens.  There is some manipulation of discarded food items and other items – like rocks – by octopuses in their dens, most often to close or partially close the opening to the den.  But I’ve never noticed anything like a systematic arrangement of items as a means of communication (like some birds do, such as bower birds) or artistic expression – no self-portraits that I’ve ever noticed, despite the intelligence of the species I’ve studied!  Note: this is not to say that something like communication through prey discard items isn’t possible.  I could see how it could evolve (and maybe that would be something to look for!), I just don’t know of any examples of it occurring.

So, as far as I know midden formation is likely to occur anytime octopuses den in one place for any period of time.  This is restricted to relatively shallow water octopuses.  Even then, most octopuses living on soft bottom habitats would not produce dens under most circumstances.  Deep sea octopuses and pelagic species do not, as far as I know, take shelter in dens or produce middens.  This makes sense; there are no caves or holes in the deep sea, for the most part.  Especially any species that would forage widely, like up in the water column, would have little reason to return to a particular place to eat.

I know of no examples of non-octopus cephalopods (squids or cuttlefish) producing middens.  Cuttlefish closely associated with reefs might be a reasonable candidate for producing middens, but I have never heard of this. Any cuttlefish or squid living in the water column would be extremely unlikely to produce middens.

JM: Middens aren’t really built.  Octopuses do build ‘walls’ of rocks in front of the home.  But when they eat prey at home, they just push out or blow out with a jet of water, or leave shell remains in the home. It’s more like a garbage heap.  We don’t know a lot about octopus species, we’re particularly short of field work.  However, midden remains have been assessed in the Mediterranean, the Caribbean and Bermuda, off the coast of Brazil and up the Pacific coast of North America (these are published papers, there are probably other assessments). My guess is that it evolved fairly early in the ancestry of octopuses, it’s likely widespread because all you need is a sheltering home and the habit of tossing your trash out.  It is limited by topography, remains aren’t found where there is a strong current, they obviously get whisked away. Middens are NOT found in pelagic species because there is no place to put them, squid do not make middens and cuttlefish probably do not either.  Deep sea octopus species might, it depends on what they find to eat.

Images

Top – Illustration from Victor Hugo’s Toilers of the Sea (1888 Crowell Edition).

Middle – Figure from Elizabeth Harper (2002) “Plio-Pleistocene Octopod Drilling Behavior in Scallops from FloridaPalaios 17:3 292-296 DOI: 10.1669/0883-1351(2002)017<0292:PPODBI>2.0.CO;2

Bottom – Photograph from Flickr user Steven Severinghaus - Used under Creative Commons 2.0.

Minimalism as a trope in Early Triassic cephalopod artistic traditions

10 October 2011

The recognition that Shonisaurus death assemblages preserved in the Late Triassic aged Lunning Formation represent large-format self portraits created by hyper-intelligent Kraken like cephalopods marks the beginning of a dramatic paradigm shift in paleontology. This break-through insight requires cold reappraisal of 200 years of research and a thorough re-imagining of more than 200 million years of evolutionary history. Here, we report surprising evidence that minimalist artistic traditions were already deeply entrenched among cephalopod artists by the late Early Triassic. A single small ichthyosaur vertebrae set in a lime mud matrix confronts the viewer with ambiguous questions about mortality, corporeality, decay and emptiness. Although the precise social context of this work remains unclear, perhaps the single bone was placed in an unusual setting that undermined the “authenticity” of the piece, and underscored the inherent absurdity of art à la Duchamp’s Fountain (1917).

It seems surprising that this abstracted form antedates the highly figurative I, Kraken piece which dates to the earlier late (or perhaps later early) part of the Late Triassic. Assuming this work of understated irony is  a response to bourgeois excess, widely emulated figurative traditions must have been developed by the Permian. Alternatively, perhaps the historical trajectory of of cephalopod aesthetics followed a very different course than that of 20th Century Western societies (human). The identification of  hyper-minimalist tropes approaching the Suprematism of Malevich or the early works of Rauschenburg, could help to better establish the temporal polarity of the evolution of aesthetic movements in Mesozoic (and even Paleozoic) cephalopod art.  Thus particular attention should be paid to works of cephalopod art that show no clear signs of being “made,” whether they be barren bedding planes, massive mudstones entirely devoid of fossils, or even paraconformities.

Cranchid Crankiness

7 May 2010

It seems the Conservative, uh victory?, in the UK is having an effect on the state media already.  Check out this extremely toned-down version of the classic squid/whale/bus chart.  Gone is the blue gradient fill, exaggerated length estimates, hey, even the scale bar has been cleaned up.  And we haven’t lost our scepticism about whether this squid is truly colossal or just ‘colossal’.  It’s a new era of teuthous responsibility I suppose.

Though, not so much with the ‘facts’:

Its large size and predatory nature fuelled the ancient myth of the underwater “kraken” seamonster and modern speculation that the colossal squid must be aggressive and fast, attributes that allow it to prey on fish and even give sperm whales a hard time. -“Monster colossal squid is slow not fearsome predator” Jody Bourton BBC April 7 2010

It is not quite clear to me how a squid native to Antarctic waters and discovered in 1925 influenced Medieval European mythology, but, hey, you know, whatever.  I also like the image of Mesonychoteuthis giving Physeter a ‘hard time‘:

“Hey sperm breath–where you going?  Oh, you’re going to eat me?  Ooooh I’m soooo scared…”

To be fair, the general tone of the article is pretty true to that of the new study on which it is based (Rosa and Seibel 2010).  It’s a neat, albeit rather hypothetical paper, that takes what little is known about the anatomy of the world’s largest invertebrate and plugs it into a model based on the relationship between water temperature, body-size and metabolism observed in other squid species.  These parameters suggest that Mesonychoteuthis hamiltoni is a cool and calculating cold-blooded killer that ambushes its prey.

Both Rosa and Seibel and the BBC article insinuate that this is something of a surprise, flying in the face of previous theories that Mesonychoteuthis hamiltoni was an active predator.  However, it seems to me that a low metabolic rate, with reduced feeding rates and activity patterns, would be the default assumption for an enormous ectothermic invertebrate living in very deep, very cold waters.  It would be interesting to know how the metabolism and activity pattern of juveniles, which start out life only a few millimeters long and generally live in shallower waters, differs from those of 15 m long adults.  Well, interesting to me anyway.

Photo from the awesome Te Papa museum Colossal squid dissection blog

At any rate though, I’m with Arch Anemone on this one.  By the BBC’s criteria, crocodiles, anacondas and bird-eating spiders aren’t fearsome like chihuahuas and dragonflies.  Okay, chihuahuas and dragonflies are pretty fearsome.  But I think a 15 meter long squid lurking in the darkness  just waiting for something to bump into an enormous tentacle lined with swiveling hooks which will drag it down into its snapping beak?  That’s pretty damn fearsome too.

Plus anything that eats Toothfish is worthy of respect.  Unless you call them “Chilean Sea Bass.”  Then you should be ashamed of yourself.

Rui Rosa and Brad A. Seibel 2010 Slow pace of life of the Antarctic colossal squid. Journal of the Marine Biological Association of the United Kingdom, Published online by Cambridge University Press doi:10.1017/S0025315409991494

I was supposedly leaking the most interesting colors

5 February 2010

Straight-shelled nautiloids showing traces of original shell coloration - Plate 1 from Foerste 1930

So far, I suppose, the take home message is that Mesozoic theropods were nowhere near as stylish as Paleozoic cephalopods.  Shocking that.

I was going to cobble together one of those insufferable “hold on a minute, let’s consider the broader historical context of this discovery” type posts, highlighting some of the hundreds of other cases of color preservation in the fossil record (mostly among plants, insects and marine invertebrates).  Blah blah blah, Grès à Voltzia blah blah Clarkia flora blah blah Burgess Shale! &c.

But, you know, it’s Friday afternoon, so let’s just watch this Animal Collective video instead.  I’m pretty sure that this song, “Peacebone” is about the Jehol biota.  That, or taking LSD.  Which, by the way, if you are on acid you probably shouldn’t watch this video.  Otherwise, enjoy the Toxicodendron cameo at 0:30!

I’m taking the weekend off to grade papers, see you next week!

Permanent Ink

24 January 2010

squidink_1464882c
Which reminds me…

I meant to write about this when it was news.  Now it’s olds, which suits me fine.

Copy of Pearce's restoration of Belemnotheutis, re-drawn by Colin Stuart from Donovan and Crane (1992).

I.  The drawing above is of the extinct Jurassic cephalopod Belemnotheutis antiquus. In fact, it’s a fairly exact replica of a drawing made by Joseph Chaning Pearce who first named the genus in 1842 (shown at left).  Pearce may have intended to name the fossil Belemnoteuthis (teuthis=Gr. squid as in teuthology study of cephalopods), or he may have intentionally used a variant spelling.  Either way, Donovan and Crane 1992[pdf] argue that the original published spelling should stand according to the rules of taxonomic nomenclature.  Historically, Belemnoteuthis(sic) has been widely used and Richard Cowen has described Pearce’s original spelling as “barbarism.” Nevertheless there it stands: a possible typo enshrined into taxonomic priority.

II.  Engineering icon Isambard Kingdom Brunel, was the vision behind the construction of the Great Western Railway which linked London by rail to south west England (including the Jurassic Coast) and Wales during the 1830s and 40s.  Around 1840, rail workers constructing a line near the village of Christian Malford stumbled across incredibly well preserved fossils some of which were collected and studied by Pearce.  The site was eventually flooded and forgotten for more than a century and a half before it was rediscovered by British scientists just a few years ago.

III.  Which, the focus on all those new reports about that featured this drawing wasn’t mainly on the historical quirks surrounding the image or name at all but concerned instead the historical quirks surrounding the origin of the ink which is: FREAKING BELEMNITE INK!

Ink from a well-preserved Belemnotheutis, dead for 165 million years or so, was reconstituted and used to draw a copy of one of Pearce’s original drawings.

IV.  Which is really cool, but not nearly as unique as you might expect.

Joel Segal Books Blog does a nice job of putting fossil cephalopod ink into proper historical context, borrowing an image from my sidebar, a painting of Ichthyosaurus made by Henry De la Beche in 1834 using FREAKING BELEMNITE INK!

From Clary (2003)

Credit where it’s due: I nicked the picture from the doctoral dissertation of Renee M. Clary (2003) which explores the pioneering role De la Beche played in using imaginative visual aids to convey geological and paleobiological information.  Mandatory reading for anyone interested in the history of geology, the use of illustration in the earth sciences or the development “paleoart.”

Preserved ink sacs of fossil cephalopods - from William Buckland's Geology and Mineralogy with respect to Natural Theology (1836).

In fact, De la Beche was just one of a number of 19th century scholars and artists that messed around with reconstituted fossil ink.  In his “Bridgewater Treatise” Geology and Mineralogy with respect to Natural Theology (1836) William Buckland illustrated (so far as I know, with conventional ink),  the well-preserved ink sacs from several fossil cephalopods.  In that same work, Buckland gives an account of one of the earliest artistic experiments using fossil cephalopod ink:

Elizabeth Philpot, the often forgotten friend and associate of Mary Anning who is a central character in Tracy Cevalier’s recently published novel Remarkable Creatures, is also said to have painted with “fossil sepia” and sometimes credited with being the first to do so.  Other enterprising residents of Lyme are said to have followed suit painting  in an effort to cater to the burgeoning tourist industry fueled by Victorian fossil fever and the construction of the Great Western Railway.

I’m not sure whether any of the illustrations made by Chantrey, Philpot or their followers have survived, I haven’t been able to turn any up aside from De la Beche’s ichthyosaur.  Unlike the De la Beche drawing, other vintage fossil ink works might not be clearly labeled as such and could easily be sitting in a private collection or a museum forgotten and unrecognized.  Philpot’s or Chantrey’s original works, most likely long gone, would be priceless historical gems of the finest order.

V. Fossil ink makes literary cameos in the work of Jules Verne and the poet Martin Farquhar Tupper.  It also turns up in one of my favorite essays of all time, Thomas Henry Huxley’s “On the Method of Zadig”:

“No amount of physiological reasoning could enable any one to say whether the animal which fabricated the Belemnite was more like Nautilus, or more like Spirula. But the accidental discovery of Belemnites in due connection with black elongated masses which were: certainly fossilised ink-bags, inasmuch as the ink could be ground up and used for painting as well as if it were recent sepia, settled the question; and it became perfectly safe to prophesy that the creature which fabricated the Belemnite was a two-gilled cephalopod with suckers on its arms, and with all the other essential features of our living squids, cuttle-fishes, and Spirulæ. The palæontologist was, by this time, able to speak as confidently about the animal of the Belemnite, as Zadig was respecting the queen’s spaniel. He could give a very fair description of its external appearance, and even enter pretty fully into the details of its internal organisation, and yet could declare that neither he, nor any one else, had ever seen one.”  Thomas Henry Huxley “On the Method of Zadig” (1880)

VI.  Pigments, paints, dyes and inks come either from dead organisms or minerals, and so all have some biological or geological story to tell.  The case at hand straddles both categories, which seems unique until you remember the ubiquity of “synthetic” inks distilled from petroleum that is the remnants of marine organisms, dead and buried for millions of years.  That might include some of the ink used to run the Belemnotheutis newspaper stories, unless British newspaper printers have all switched to soy-based inks like their U.S. counterparts.  Your keyboard and mouse are probably made from sea animals.  If you print this post out (which I can’t imagine why but just go with me here) the ink you use, and perhaps the energy to do it, are quite possibly the byproducts of long dead phytoplankton.

VII.  And as long as we’re talking autochthonous/authigenic art, I have to mention Matt Celeskey’s work with 200+ million year old Triassic charcoal.  Matt, in turn, turned me on to Alexis Rockman whose “field drawings” use site-specific pigments themed around of both living and fossil ecosystems ranging from the Burgess Shale and La Brea Tar Pits to Fresh Kills landfill.

VIII.  Here then for almost no reason except that I like the picture is Brunel, posed beside the launching chains of the SS Great Eastern, whom Brunel affectionately called the “Great Babe.”  The ship will experience a steam explosion, killing 5, before being repaired, sent across the Atlantic as a passenger vessel half-a-dozen times nearly sinking once before being converted to cable laying ship and laying the first Trans-Atlantic telegraph cable, later converted into a floating music hall and promotional gimmick and eventually broken up and sold for scrap.  Which has nothing to do with anything.  Like I said, I just like the picture.

And if you made it this far without being tempted by at least one of those hyperlinks, I can’t help you.

PZ Myers Signed My Squid

22 January 2010

Loligo opalescens (click for hi-res version)

“I just need one whole squid.” To his credit, the fishmonger did not bat an eye.  Even better, he gave it to me free of charge.

Later, before the talk, I confessed, “I have a mollusc in my pocket.” “Me too!  I have a limpet that’s been in there for 2 years.”  “Neil’s is a bit fresher than that.”

Later, “Oh no. What have you done?” saith PZ Myers,  “This almost feels wrong.” (I’d like to report he said ‘sacrilegious,’ but he didn’t.)

“What are you going to do with it?” asketh PZ, “Are you going to eat it?”

“Well, it’s been sitting in my pocket for a few hours”

“I wouldn’t recommend eating it then…”

Wise words from a wise man.  Likewise when he compared Ray Comfort to an incompetent sphincter.

The squid is in the freezer with Spike the water monitor.  I think I’ll name it PZ Jr.

The Squid and the Bus

8 October 2007

Okay, I’ve been sitting on this one for awhile, waiting for:

a) BBC to run another squid story, and

b) The chance to stage a photo holding an uncooked calamari squid against one of Davis’ infamous (and hazardous!) double-decker buses

Lo! Much as Darwin was forced to rush his theory of natural selection to publication after a few short decades of musing, I’ve been goaded into action by an irresistible outside force that demands my immediate attention.

So in honor of the First Annual Cephalopod Awareness Day (!) please enjoy this ‘brief abstract’ of which I will someday provide a deep and thorough elaboration upon more befitting the quality writing you’ve come to expect here at microecos. Just think of it as my personal Origin .

Without any further ado, then, let us explore the evolution of the BBC’s celebrated Mesonychoteuthis v. London Double-Decker Bus diagram or as I like to call it, “The Incredible Shrinking ‘Colossal’ Squid”:

BBC NEWS, 2 April 2003 — “Super squid surfaces in Antarctica

That Sperm Whale looks freaked out.

 

BBC NEWS, 8 January 2004 — “New giant squid predator found

Oooh-look a border! Hey, where’d the whale go? Oh, eaten by a sleeper shark no doubt.

BBC NEWS, 28 September 2005 — “Live giant squid caught on camera

Wait, maybe the whale ate the shark. Giant and ‘Colossal’ both get downsized, and makeovers. Who’s the little guy?

BBC NEWS, 28 February 2006 — “Giant squid grabs London audience

New color scheme! Whale shrinks, Colossal grows back to ? size. Ominous caption: “Scientists admit they know little about the largest of the squid”

BBC NEWS, 14 February 2007 — “Large squid lights up for attack

Little guy’s back…actually mentioned in the text this time. What he lacks in brawn he makes up for in special effects, apparently swimming the wrong way though.

BBC NEWS, 15 March 2007 — “Colossal squid’s headache for science

Stasis…

BBC NEWS, 22 March 2007 — “Microwave plan for colossal squid

“Arghhh! They microwaved me down to shark bait!” Shouldn’t the mass figures be expressed in elephant equivalents?

And just to prove that everything is scarier in Russian:

Hmm, so if ?=20 and ???=25 then ??=uh, carry the one … invert the denominator … cross multiply. Damn, I never was any good at algebra.

Fortunately there’s a handy online calculator that allows me to convert any length into london-bus equivalents: the Size of Wales calculator!

An inky Cephalopod Day to all, go check out the tentacley goodness over at Cephalopodcast.

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