Monday, December 14, 2015

Micro to Macro, Nature to Art

Scale.  It’s an ongoing effort to strike a proper or, perhaps, comfortable balance.  Walk along 10th Street toward the Smithsonian’s National Museum of Natural History and lurking on either side are the massive, stolid buildings of the U.S. Justice Department and the Internal Revenue Service.  The message about one’s insignificance is clear.  Reach Constitution Avenue, a broad, multi-laned river of traffic, extending to the right and left.  Cross the avenue to the museum.  Before the entrance, two small gardens sit island-like, bordered by stone.  These restore some degree of welcome equilibrium.  Even the trees, ginkgo (Ginkgo biloba) and European larch (Larix decidua), in these garden islands are modest.

Curiously, the recent, sudden appearance in the gardens of two very much larger-than-life sculptured models of microscopic foraminifera shells has not upset that equilibrium.  These stone models, each roughly two to three feet long, represent two extant species of these tiny (typically less than ½ millimeter in length) single-celled marine protists.  Most species create multi-chambered shells, adding new chambers as they outgrow the array of earlier ones.  The species modeled here are Buzasina ringens from the South China Sea (the first image below), and Ishamella apertura from Florida (the second and third images showing a side of the model and the shell’s aperture).

I don’t know the full story behind these foraminifera sculpture; a couple of inquiries of the NMNH have yielded nothing.

The fashioning of three-dimensional, enlarged models is not unique to foraminifera among students of microorganisms.  Indeed, leave the gardens and wander into the Museum’s Sant Ocean Hall.  Once there, admire a beautiful model of a dinoflagellate (Cyratocorys horrida), enlarged 1,000 times from a 0.15 mm actual specimen:

Or, to push the issue of scale even more, wonder at the explosive action frozen in the model of a radiolarian (Didimocyrtis tetrathalamus) enlarged 3,400 times from a 0.06 mm specimen:

Though there is a long history of the creation of models of very small organisms, I sense something unique about the modelling of foraminifera shells.  For a variety of reasons, which I will consider (i.e., fumble with) in a moment, foraminifera shells seem to cry out to be rendered in large scale models.

Engaged in creating the first systemic classification of foraminifera, the Frenchman Alcide d’Orbigny issued, in 1823, the initial of four installments of plaster models of foraminifera.  These models were based on original limestone sculptures that he’d carved.  Each installment contained 25 models; those of extinct species were colored, recent species were white.  Each model showed a foraminifera specimen; many were between 1 and 2 inches long.  Most amazing, the first installments of d’Orbigny’s models were sold to subscribers three years before they received his text describing and categorizing foraminifera genera and species.

In that publication, d’Orbigny placed the foraminifera into their own order with 5 families, 64 genera, and 544 species.  At the time, he mistakenly believed foraminifera were cephalopods, part of the mollusc phylum.  While only a few plates accompanied the text, illustrating just 31 species, d’Orbigny had a much more extensive array of plates that were intended for publication, but his foraminifera work was seriously disrupted in 1826 when the 24-year-old naturalist embarked on an eight-year journey to South America (described in a previous post).

Pictured below are several examples of d’Orbigny’s plaster models.  The California Academy of Sciences has posted many images of these models on Flickr and generously allowed them to be used under the Creative Commons Attribution Noncommercial-NoDerivs 2.0 Generic license.  The brightness and contrast on each image has been adjusted to enhance the details of each model.  There are three images of each model showing two sides and an edge.

Anomalina elegans

 Globigerina bulloides

Gyroidina orbicularis

Hansenisca soldanii (originally named Gyroidina soldanii by d'Orbigny)

Siderolina laevigator

(The preceding discussion of d’Orbigny’s work is based on various sources, including the following:  d’Orbigny’s 1826 publication titled Tableau Méthodique de la Classe des Céphalopodes, Annales des Sciences Naturelles, Series 1, Volume 7, 1826; Jere H. Lipps, The Unpublished Plates of Foraminifera by Alcide d’Orbigny – the Dawn of Micropaleontology, Palaeontologia Electronica, Volume 9, Issue 2, 2006; Edward Heron-Allen, Presidential Address, 1916-17:  Alcide d’Orbigny, his Life and his Work, Journal of the Royal Microscopical Society, February, 1917; Paul D. Taylor, Picture Quiz:  Alcide d’Orbigny (1802 – 1857), The Linnean, Volume 18, Number 2, 2002; C. Giles Miller, A Brief History of Modelling Foraminifera:  From d’Orbigny to Zheng Shouyi, in Landmarks in Foraminiferal Micropalaeontology:  History and Development, A.J. Bowden, et al., editors, The Micropalaeontology Society, 2013.)

Giles Miller offers an overview of some of the story of foraminifera models in his excellent piece, A Brief History of Modelling Foraminifera (cited above with a link).  Miller, Curator of Micropalaeontology at the Natural History Museum, London, describes numerous modelling efforts, some of which involved mass production (I guess that's what it would be called) like d’Orbigny’s models, while others consisted of models created by a single scientist for his own use.  He notes that “other sets of foraminiferal models not covered in this paper almost certainly exist . . . .”  (p. 337)  Miller describes nearly a dozen sets of models or individual models created at various points in the last couple of centuries.  Among them are those marketed in roughly the middle of the 19th century by the Czech Václav Frič whose models reflected the scientific thinking of the Austrian August von Reuss; the single set of glass and plaster models made by Frederick Gordon Pearcey, a member of the famous H.M.S. Challenger expedition of the 1870s (subject of a previous post); the plaster models created by someone named Chaffer and marketed in the early 1900s in England; sets of 50 “different forms” of foraminifera that were created by geologist Brooks F. Ellis and one his students, Julian Kane, and sold in the U.S. and Europe in the early 1950s; and the 4 sets of 10 models each currently sold by Kane Scientific.

One modelling effort merits separate treatment.  Expanding from her creation of hand-sized models, Chinese scientist Zheng Shouyi spearheaded an effort to create a park in Zhongshan, China, which opened in 2009 and features 114 huge marble, granite, and sandstone sculptures of foraminifera.  Some dwarf the people standing beside them, providing a sense of their scale.  Pictures of the park appear in Giles Miller’s article cited earlier and in Karen Larkins’ piece titled Evolution World Tour:  Foraminifera Sculpture Park, China (Smithsonian Magazine, January, 2012).

Why this strong impulse to fashion foraminifera models?  Based on my own work with foraminifera fossil shells, I will hazard that, at some fundamental level, foraminifera naturally lend themselves to modelling, partly because they come in such a breathtaking array of different shapes (reflecting the myriad ways the chambers in the shells are arranged, as suggested by the d’Orbigny models shown earlier), and partly because distinguishing among species often demands consideration of specimens in three dimensions.  To make key distinctions, one often has to examine, under magnification, all facets of a shell from all angles, and be able to relate those facets, one to another.  Drawings and photographs, even (or particularly) SEM (scanning electron microscope) images, are not always up to the task.

As delineated in Miller’s piece, modelling of these protists has often arisen from an educational impulse, within both academic and museum settings.  Clearly, that instruction can serve a very specific agenda.  For example, d’Orbigny saw the models as offering a critical way to demonstrate and promote the classification system he was propounding for foraminifera.  As he explained, “With a view to giving greater publicity to the work I had undertaken, and with the object of making it available to everybody without entailing the necessity of observing the numerous genera of Foraminifera under the Microscope, I have had the idea of sculpting a shell of each genus and each sub-genus of this order . . .”  (As quoted in Heron-Allen, cited earlier, p. 14.)

As d’Orbigny noted, a means of magnification is a necessity for observing these shells, potentially limiting their accessibility.  Though he prepared drawings of many of the shells covered in his Tableau (of which only a few found their way into the publication), he evidently believed these were insufficient for the task at hand.  Hence, the models.

I was amused at Heron-Allen’s comment that some of his own late 19th and early 20th century contemporaries who studied foraminifera looked askance at such models because, he reasoned, they failed to consider that d’Orbigny did not have at his disposal “microphotography” which Heron-Allen posited had “revolutionize[d] the study of microscopic life.”  (p. 14)  Heron-Allen might be surprised at the continued production of models up to the present, even as improvements in the photographic imaging of microscopic specimens have continued apace.

Indeed, in terms of developing technology, a marriage of 3-D printing and foraminifera shells seems ideal for foraminifera.  Micropaleontologist Ellen Thomas is part of an NSF-funded effort promoting that marriage, and her teaching now includes models of foraminifera and ostracodes generated by 3-D printers through a process that begins with CT scans of specimens to create 3-D “virtual fossils.”  Thomas notes, “With this, the fossil becomes a real object.  It becomes tactile and tangible and becomes a real teaching tool.”  (Olivia Drake, Thomas Uses CT Scans, Computer-Aided Visualization to Study and Teach Microfossils, News@Wesleyan, Wesleyan University, February 10, 2015.)  Yes, very tactile and tangible as shown below in a picture of one of her 3-D printed models of a Cibicidoides wuellerstorfi.

(This picture, which appears in the article just cited, is reproduced here with the kind permission of Olivia Drake at Wesleyan University.)

A micropaleontologist who works with other kinds of microfossils suggested to me that perhaps there’s a bit of a “founder effect” at work with foraminifera modelling.  As already noted, d’Orbigny, who laid the groundwork for the study and classification of foraminifera, started with models before text and drawings.  Perhaps that has biased subsequent workers with these shells.  It’s a thought.

One additional and, perhaps, key reason for the continuing creation of these models is how beautiful foraminifera shells are.  As the sculptures in the gardens before the National Museum of Natural History attest, scale up these microorganisms into hand-sized or larger objects and we cross from works of nature to works of art.

Monday, November 16, 2015

Pieces of State ~ Samples from State Geological Surveys

When I recently visited the website of the Wisconsin Geological and Natural History Survey (aka, the Wisconsin Geological Survey), I was surprised to find that I could buy pieces of the state . . . literally.  So I did.  For $35 (plus $7.50 for postage), the Survey sent me a selection of 15 Wisconsin rocks, minerals, and a fossil.

I was even more pleasantly surprised when the set arrived.  Solely in terms of its sheer weight, the set is impressive, coming in at approximately 6 pounds.  And, even better, the Survey didn’t send little, dinky samples; rather, I had spread before me rather sizeable chunks of rocks and minerals, among them calcite, basalt, zinc ore, iron ore, and dolomite (these specimens are pictured below).

This rock and mineral set is just one way the Wisconsin Survey fulfills its educational mission, a mission the Survey clearly takes quite seriously.  Accompanying this material is the informative Wisconsin Rocks & Minerals, by Meredith E. Ostrom and Roger M. Peters (ES046, 2012) which describes, in detail, the rocks and minerals represented by the specimens in the set.

What prompted me to buy this collection, in the first place, was the supposed inclusion in it of the Wisconsin state fossil, the Silurian trilobite Calymene celebra.  I mentioned this trilobite in my previous post in which I took the novelist Steinbeck to task (perhaps too harshly) for a line he wrote about ancient Wisconsin geology and paleontology (My Apologies, John Steinbeck, But I Care About Things Like This).  The Survey website was in error (since corrected); what I received, instead, was a modest slab of sandstone from the Eau Claire Formation covered with a rich stew of molds and casts of pieces of the cephalon (head), thorax, and pygidium (tail) of Cedaria woosteri, a much older trilobite from the Cambrian.   On the left is a picture of the full slab, on the right is a closeup of a section of it.

Besides the fossil error on the website, there were a few other hiccups in the acquisition of this set of rocks and minerals (such as the loose piece of sandstone included in the set which did what sandstone is supposed to do – break around individual crystals – leaving the box reminiscent of the aftermath of the trip to the beach with the kids).  Still all of that is outweighed by the quality and amount of material I was received.

In fact, I was so taken with this set (and hoping that lightning would strike twice) that I set out to determine whether other state geological surveys sell to the public similar sets with pieces of their state.

First, though, a little background on state geological surveys which are state-funded entities.  According to a committee of the American Institute of Professional Geologists,
The state geological surveys serve our country in a significant role by providing unbiased and sound scientific research, geologic data and maps, and reports to the public, industry, academia, government agencies as well as local, municipal, county, state, and federal legislators and regulators.  (Importance and Future Roles of State Geological Surveys, undated)
I’ve written about state geological surveys on this blog before (State Geological Surveys – Rare Moments of Civilized Joy in the Quest for Online and Free, November 7, 2010).   If their online presence is any evidence, these state-funded entities vary quite remarkably, one from the other.  Some appear more robust and substantial than others (indeed, there isn’t one in Hawaii), and some seem to be about serving and educating the public more than others (for instance, the Iowa Survey’s website has an Education and Outreach tab that opens to reveal a page dated October 3, 2014 with the message:  “Coming soon!!!!!!!!!!!!”).  Of course, some of this may have to do with how fully and effectively they’ve embraced being on line.

Nevertheless, I believe what one finds online partly reflects key structural and programmatic differences among the state survey entities.  That same committee of the American Institute of Professional Geologists observed,
The responsibilities of the surveys vary somewhat from state to state, depending upon the enabling legislation, the specific needs of each state and the traditions under which each survey evolved. . . .  About one-third of the state geological surveys function under a state university system while the other two-thirds operate as part of state government, either as a stand alone agency or as part of a larger state governmental entity.  Most state surveys are non-regulatory whereas some have enforcement duties.
Basic message:  state geological surveys are a mixed bag.

With that as context, let me share what I found when I recently visited (from October 28 to November 8) all of the state geological surveys’ websites in search of state-specific rocks, minerals, and fossils for sale, either individually or in prepackaged set.  The results were disappointing, to say the least, particularly for this inveterate collector of fossils (and, on occasion, rocks and minerals) and given that I’d started with the Wisconsin Survey (which had given me such high hopes).  I found only 12 state surveys from which I could buy specimens (these specific sites were revisited on November 16):

* Arizona
* Arkansas
* Connecticut
* Missouri
* Montana
* Nevada
* New Jersey
* Pennsylvania
* South Carolina
* Texas
* Wisconsin

During these revisits, I found that the website of the 12th, the Virginia Department of Mines, Minerals, and Energy, from which I recently purchased a rock set (see below), is undergoing construction and the specific webpage is not now available.  (Things certainly are fluid out there.)

With the haphazard layout of some survey websites, it’s possible I may have missed one or two surveys that sell specimens, but I doubt it.  Also, I would stress that these sites do not all provide for online sales.  Further, the Montana link above is to a page which simply and briefly describes the "Mineral Museum Gift Shop."  I have assumed from the pictures there, that one could visit the gift shop in person and purchase rocks and minerals.

The inclusion in the list above doesn't mean that a state offers a set of specimens comparable to that from Wisconsin.  Though several have sets of rocks and minerals from their state for sale, for the most part these appear to include rather small specimens.  The one I purchased from the Virginia Survey (“The Boxed Set of Twenty Rocks and Minerals from Virginia,” $10.50), pictured below, represents one approach:  little specimens glued into a display box (a pretty display, but, frankly, probably not something to go out of your way for):

The Virginia set does include a piece of petrified wood from Chesterfield County, Virginia, as well as a cryptic note on the box lid that these items are “from the collection of Rudolph J. Bland, Jr.”

A few of these survey sites (e.g., Arizona and Connecticut) link the visitor to a state-sponsored store selling books and other merchandise, including rocks, minerals, and, infrequently, fossils.  Some, but not all of what’s for sale, comes from the state in question.  For instance, Connecticut’s site offers a set of fossils that were collected around the world and around the U.S., though not in Connecticut.  I would note that Connecticut's rock and mineral set ($15 and an additional $4.95 for postage) does provide a nice selection of modestly sized Connecticut specimens, certainly on the Wisconsin end of the spectrum of these sets.

I’ve thought a bit about whether state geological surveys should be in the business of selling rocks, minerals, or fossils from their states to the general public, and am inclined to endorse the activity.  It makes sense to me as part of the surveys’ mission of educating the public.  And, hey, if these sales are moneymakers, then the case is even stronger (I cannot believe these entities are generally well-funded by their states).  Is there a supply side issue that needs to be taken into account, one that precludes more agencies from selling specimens?  For instance, the Arkansas Survey’s website notes that state rock and mineral packets are available for classroom teachers (and for sale to the general public), but that packets wont be provided for students to take home “due to decreasing resources and inventory and increasing costs of shipping the rock packets.”  Maybe one sees it as a bit unseemly for a state entity to be quite so commercial with the objects in its scope of responsibility.  But, in light of the history of the origins of state geological surveys in the 19th century, it may be totally appropriate.  It would appear that they have long had a commercial side as well as a resource management mission.  They largely came into being to support the internal improvement and development of states, particularly road and canal building, and to identify the locations of rocks and minerals that could be mined.  This commercial impulse was also often married to an educational one.  (See, Walter B. Hendrickson, Nineteenth-Century State Geological Surveys:  Early Government Support of Science, Isis, Volume 52, Number 3, 1961.  It is hiding behind a paywall.) 

In the final analysis, few state geological surveys do this and, as luck would have it, I started with Wisconsin which does it apparently best of all.

Friday, October 23, 2015

My Apologies, John Steinbeck, But I Care About Things Like This

Remember.  No matter where you go, there you are.
 ~ Buckaroo Banzai
(The Adventures of Buckaroo Banzai Across the 8th Dimension, movie released in 1984, script by Earl Mac Rauch.)

There are moments when my consuming interest in natural history, and, in particular, things paleontological and geological, wreaks havoc with my non-scientific reading.  There I am, engrossed in a work of fiction or non-fiction that has no ostensible link to natural history, when the author touches on the natural sciences.  A little current crackles somewhere in my brain and I say to myself, “Hey, look at that!” – and mentally, if not literally, I underline the passage.  I cannot ignore this alert.  And that initial surge of excitement may come with a critical edge – Did the author get it right or not?  Do I really know one way or the other?  Damn, it would be so much easier just to let it slide, assume it true, and continue in the author’s company heading to wherever he or she wants me to go.  Instead, I’m compelled to take off on a bit of research.

I just reread John Steinbeck’s Travels with Charley:  In Search of America, published in 1962.  Steinbeck recounts a journey he took in 1960 across America traveling in a specially outfitted camper truck with his French poodle Charley (surely one of the best road buddies in literature).  This was all in an effort to get reacquainted with America, a place he felt he’d lost touch with after living for many years in New York, France, and England.  He wanted to recharge his literary batteries and also felt the need to prove that he was physically able to make this quest.  Steinbeck, who had been in poor health, was, in fact, counseled not to do it.

This book has carried different messages for me depending upon when I read it.  It was a gateway drug for an adolescent who found the idea of abandoning one’s self to the road nearly irresistible (though I did resist it).  With my teenage years having faded long ago in the rearview mirror, I was disappointed to find that the book has lost much of its allure.  Structurally, it’s disjointed and uneven, littered with set pieces.  There’s a strong current of dissatisfaction with much of what Steinbeck encountered.  The carping can get tiring; the reader sometimes wants out.

Yet, Travels does have sparks of beautiful prose as well as occasional insights into America that still ring true.  Steinbeck wrote movingly on environmental degradation, media-fed anger and hatred (he described the vitriol spewed by a white crowd at a solitary African American child integrating a school in New Orleans, and how leaders of the protesters were fueled by their coverage in the press), and the (not unique) propensity of many Americans to blame, however irrationally, someone else, some other group, for their ills (a Minnesota shopkeeper opined that, in 1960, what really set people off in a public way were the Russians who were felt to be behind everything wrong; before that it was Franklin Roosevelt – “Andy Larsen got red in the face about Roosevelt one time when his hens got the croup.”).

Travels is, I think, a lesser work from a first rate author who was past his literary prime.  To add insult to injury, there’s evidence that he made up at least some of the book, fabricating dialogue, exaggerating how much time he actually spent camping out in his truck, minimizing how often he was joined by his wife, . . . .  (Charles McGrath, A Reality Check of Steinbeck and Charley, New York Times, April 3, 2011.)

This matters more to some people than others.  Bill Barich, author of Long Way Home:  On the Trail of Steinbeck’s America (2010) struck a good balance.  He is quoted in the 2011 New York Times piece as saying, “I’m fairly certain that Steinbeck made up most of the book. . . . But I still take seriously a lot of what he said about the country.  His perceptions were right on the money about the death of localism, the growing homogeneity of America, the trashing of the environment.  He was prescient about all that.”

(Barich’s book is an interesting read.  His journey across America did not follow Steinbeck’s path, but, rather, was an attempt to do what Steinbeck set out to do – take the pulse of America.  Unlike Travels, which cannot be used to trace a precise track across the country, Barich’s Long Way Home is an almost too painful town-by-town account of his journey.  He’s also guilty of at least one egregious error of fact.  When he’s in Dodge City, Kansas, he mentioned the radio and TV show Gunsmoke which was set there.  He asserted that the show’s main character, U.S. Marshal Matt Dillon, was “modeled on Raymond Chandler’s hardboiled Lew Archer . . . .”  (p. 164)  Ouch, Chandler’s private eye was Philip Marlowe, author Ross Macdonald’s was Lew Archer.  As a devotee of the hardboiled detective genre, I almost quit the book at this flub.)

To be honest, made-up dialogue and the like really don’t bother me much.  Travels smacks of fiction almost from the outset.  Steinbeck’s harrowing rescue of his boat when Hurricane Donna slammed into Long Island (where he was living) just before he was to go on the road may be true, but it certainly reads like fiction.  Jay Parini, in his introduction to the 1997 Penguin edition of Travels, described this rescue as “a paradigmatic moment in the larger arc of the story” (p. xii) in which the hero plunges into the fray, achieves his goal, and returns to his loved one.  All a bit literary.

Someone suggested to me that Travels is like the drawings in a good birding book that, to facilitate identification, emphasize or exaggerate the key elements of different bird species.  The images don’t faithfully represent any individual specimens, rather, they capture critical truths about the different species.  So it is with Travels with Charley.  It may not be great literature and its details are suspect, but it still offers up some key truths about America.

But some realities shouldn’t be open to abuse, no matter how worthy or benign the intent.  The following brief passage in Travels triggered my natural history alert:
Beside the road I saw a very large establishment, the greatest distributor of sea shells in the world – and this in Wisconsin, which hasn’t known a sea since pre-Cambrian times. (1997 Penguin edition, p. 98)
To Steinbeck, seashells in Wisconsin were anomalous, not because the nearest sea was now hundreds of miles away (as I, with my tepid prose, would have summed up the disconnect), but because Wisconsin “hasn’t known a sea since pre-Cambrian times.”  It is a great line, powerfully capturing the alien nature of seashells in Wisconsin.

The geologic time scale table below shows the periods of the Paleozoic Era.  It's helpful for the discussion which follows.  (The data in this table are from the International Chronostratigraphic Chart for 2015, published by the International Commission on Stratigraphy.  Figures have been rounded to the nearest million years.)

Geological Time Scale of the Paleozoic Era
Period Numerical Age
Permian 252 to 299 million years ago (mya)
Carboniferous 299 to 359 mya
Devonian 359 to 419 mya
Silurian 419 to 444 mya
Ordovician 444 to 485 mya
Cambrian 485 to 541 mya

If, as Steinbeck would have it, seas last lapped somewhere in Wisconsin before the Cambrian Period, they wouldn't have done so for more than 541 million years, a long, long time ago, to be sure.

Let me start with one of my discoveries from my little research distraction:  the Silurian trilobite Calymene celebra, first described by paleontologist Percy E. Raymond in 1916, was made the Wisconsin state fossil in 1986.  (P.E. Raymond, New and Old Silurian Trilobites From Southeastern Wisconsin, With Notes on the Genera of the Illaenidae, Bulletin of the Museum of Comparative Zoology, Volume LX, No. 1, 1916.)  A lovely specimen is pictured below.

Kentuckiana Mike, author of the always interesting blog Louisville Fossils, kindly gave permission for the use of this image of a specimen found in the Racine Formation near Milwaukee.  This picture originally appeared on his blog in the post Calymene celebra Fossil on March 21, 2013.

A marine arthropod from the Silurian Period?  What this means is that C. celebra lived in warm, shallow seas in Wisconsin much more recently than 541 mya.  Seashells in the same time period?  The Wisconsin fossil shells depicted in the following plates are from the Silurian and Ordovician Periods.

The images of these plates are reproduced with the kind permission of the Wisconsin Geological and Natural History Survey and are taken from the Common Paleozoic Fossils of Wisconsin, written by Ross H. Nehm and Bryan E. Bemis, Wisconsin Geological and Natural History Survey, Educational Series 45 (2002).  They appear on pages 16 and 17 of that publication.

To sum up the Wisconsin and seas connection, I turn to the “Geologic History of Wisconsin” page, part of Milwaukee Public Museum’s extensive and informative online exhibit titled The Virtual Silurian Reef which does it nicely :
About 520 million years ago, during the late part of the Cambrian Period, a shallow inland sea spread across much of Wisconsin. . . .
An inland sea persisted across eastern and southern Wisconsin during the following Ordovician and Silurian Periods. . . .
During the Devonian Period, the inland sea retreated to southeastern Wisconsin, and by the end of the Devonian, it was gone.  For the following 360 million years, Wisconsin was a land area that did not accumulate any permanent sedimentary deposits.
I was taken with the idea of reefs in Wisconsin during the Silurian (my distractions often have their own distractions).  Turns out that these reefs that sliced across the southeastern side of the state during this period are quite fascinating and the subject of much study.  According to geologist Donald G. Mikulic, “The Silurian reefs of the Milwaukee region were the first recognized fossil reefs in North America and among the first Paleozoic reefs described in the world.”  (The Reefs That Made Milwaukee Famous, Geoscience Wisconsin, Volume 18, 2001, p. 7.)  This isn’t new information.  Actually, it was in 1862 that geologist James Hall first put forward in print the hypothesis that the limestone hills and ridges in the Milwaukee area were the remains of reefs.  As he examined the distribution of fossils in this Silurian limestone, he concluded that the only satisfactory explanation was that “[t]he entire mass appears like a coral reef, where the broken corals and shells are packed in a calcareous sand . . . .”  (Physical Geography and General Geology, Report of the Geological Survey of the State of Wisconsin, Volume 1, 1862, p. 63.)

Back to the original distraction.  Does it really make a difference that Steinbeck was wrong to assert that Wisconsin had no seas from before the Cambrian?  That he was off by perhaps 180 million years?  I guess the rational person would say, no, it doesn’t matter because, any way you slice it, the disappearance of seas from Wisconsin took place way back when.  Before the Cambrian or at the end of the Devonian, who cares?

Well, though I know it’s anal and an overreaction, I care.  These kinds of facts matter to me.  Maybe Steinbeck knew when the seas actually receded from Wisconsin (this knowledge was out there when he wrote Travels), but I suspect he found the phrase “pre-Cambrian times” to be a more creative and eloquent way to say “a long time ago.”  If that’s the case, then I’m greatly disappointed (and would only be a bit less disappointed if he were actually just uninformed or being sloppy).  I don’t think geological facts like this are to be manipulated as one might massage, or generate out of whole cloth, some conversations or parts of an itinerary because they better serve a narrative arc.

So, in the end, rereading Travels was a mixed bag:  I found some aspects of the book that I enjoyed, and some things that truly bothered me, such as my inability to recreate my warm, teenage feelings for it, the uncomfortable sadness and bitterness that course through the account, and, yes, that geological transgression.

Steinbeck’s take on America is laced with disenchantment springing, not just from what he found about the contemporary state of America, but, also from where he was in his life.  In his quest to rediscover America, to re-energize his muse, and to recover the young man he once was, I think he forgot Buckaroo Banzai’s admonition:  Remember.  No matter where you go, there you are.

Monday, September 28, 2015

Just Making a Living in the Miocene ~ Defense of the Moon Snail

In which the blogger takes undue offense and turns that into a post.
Gastropods are a challenge, raising the question, How could an animal that looks like that create a shell that looks like that?  Put bluntly, I enjoy the shells of gastropods for their aesthetically pleasing geometry.  Snails themselves, sans their shells (e.g., slugs), may be markedly less aesthetically appealing, though that should be no strike against them.  They are still fascinatingly complex and marvels of evolution.

Gastropods account for the vast majority of mollusks that have lived, or are living, on Earth.  They are, as paleontologist Donald Prothero put it, “remarkably successful,” expanding into vastly different environments, from the marine waters where they originated over 500 million years ago in the Cambrian Period, to fresh water, and then to widespread terrestrial niches, evolving lungs in the process of making that move onto land.  Although elaborate shells have evolved in some species, in others, shells have been dramatically reduced or, indeed, forsaken entirely.  Their underlying body plan “is least modified from the ancestral molluscan body plan.”  (Prothero, Bringing Fossils to Life, 1998, p. 279.)  The first gastropods were grazers, dining on algae.  (Carolyn H. Declerck, The Evolution of Suspension Feeding in Gastropods, Biological Reviews, Volume 70, Issue 4, November, 1995, p. 549.)  Over time, they evolved ways “to exploit almost every possible mode of life – as herbivores, as deposit feeders, as plankton feeders, as scavengers, as parasites, and as predacious carnivores.”  ( R. D. Purchon, The Biology of the Mollusca, 1977, p. 41.)

Recently, a friend invited me to collect fossils on the western shore of the Chesapeake Bay at a spot abounding in fossil mollusk shells, including those from a wide variety of gastropods.  Here the Little Cove Point member of the St. Marys Formation, a Miocene Epoch formation, is exposed; the fossils eroding out of the cliff sides date from perhaps 10 to 9 million years ago.

On this excursion, we found, among other shells, a wealth of moon snails, members of the family Naticidae.  Two specimens are pictured below:  I believe the first is from Neverita duplicata (among previous names for this species is Polinices duplicatus), the second is from Euspira heros (previously known as Lunatia heros).  These particular species are still with us.

This snail shell is a favorite of mine, although, until this hunting trip, I'd never found one despite their abundance.  Those in my collection came by other means.  In the process of identifying the wide variety of shells we'd collected on this trip, I was somewhat taken aback by the treatment of the moon snail by Harold E. Vokes, John D. Glaser, and Robert D. Conkwright in the Maryland Geological Survey’s Miocene Fossils of Maryland (Bulletin 20,  2nd Edition, 1999, available on CD from the MGS.)  This edition was prepared by Glaser and Conkwright based on the 1957 edition written by Vokes.

I offer this post as a defense of the moon snail.

Let me be clear, Bulletin 20 is a useful guide for fossil collectors searching along the shores of the Chesapeake Bay.  The volume features descriptions and drawings of most of the large fossil species found here, and “at least one representative of the genera that occur less abundantly.”  (p. 2.)  It also delineates in some detail the characteristics of the three marine formations of the Chesapeake Group – the Calvert, Choptank, and St. Marys – as well as the members of those formations.  Altogether, a valuable resource . . . except for the authors' gratuitous slap at the moon snail's feeding habits.

According to the Vokes and company, three species of moon snails lived here during the Miocene – Polinices duplicatus, Lunatia heros, and Lunatia hemicrypta.  (As noted above, the accepted scientific names for these species have changed.  Well, that’s true for the first two.  Tracking down the current name for the third continues to challenge me.)  Here’s the complete first paragraph of the Bulletin’s description of the family:
The species of the family Naticidae are carnivorous animals that prey upon other mollusks.  They seek out another shell and, using a peculiar tooth ribbon that is common to almost all snails, drill a small round hole through it and suck out the juices of the animal inside.  These holes, usually about one-eighth inch in diameter, are often seen in the shells of bivalves and gastropods in the Maryland Miocene fauna and are mute reminders of the unpleasant death suffered by the animal that formed the shell.  (p. 22)
I understand fully why the authors drew attention to these holes.  They are easily and widely found on fossil mollusk shells of the Chesapeake Group.  According to paleontologist Sally E. Walker, "The best trace fossil evidence of gastropod predatory activity are drill holes preserved in molluscan prey."  (Traces of Gastropod Predation on Molluscan Prey in Tropical Reef Environments, in Trace Fossils:  Concepts, Problems, Prospects, edited by William Miller, III, 2007, p. 339.  A portion of this chapter can be found on Google Books.)  More specifically, she noted that the members of the Naticidae family, in particular, "leave an excellent trace fossil record."  (Walker, p. 329.)

I don't have any quarrel with the attention Vokes and his colleagues gave to drill holes nor with their focus on moon snails in this regard.  But this is the only place where the authors provided any detail about the feeding habits of Maryland Miocene gastropods.  As a result, they seem to be suggesting that only moon snails use this method of predation.  Further, I think they, quite inappropriately, evinced a degree of revulsion with the naticid means of gaining sustenance.

My unease with this paragraph prompted me to consider how the moon snails fit into the broader context of the rest of the gastropod taxa Vokes et al. cited in Bulletin 20.  I asked and tried to answer several questions:  (1) How common were carnivorous gastropod genera in the Maryland Miocene?  (2) Among these taxa, how unique were the moon snails in this mode of attack?  (3) What other methods of predation might these taxa have practiced that could offend some sensibilities?

Prevalence of Carnivorous Gastropod Genera

Vokes and company cited a total of 55 gastropod genera.  I assume that 29 of them are extant because they appear in zoologist Harald A. Rehder’s National Audubon Society Field Guide to North American Seashells (1981).  For each family to which these genera belong, Rehder’s volume describes, often in wonderful detail, how its members typically feed.  In general, I ascribed the method for the family to any genera in that family.  When, for a very few families, Rehder described multiple, different approaches to feeding, or an unknown feeding habit, I relied on the Paleobiology Database (accessed through the Fossilworks, a portal to the database) and went with whatever it stated in its brief listing of feeding habits for specific genera under "Ecology."  I also crosschecked Rehder's family feeding description with the genera feeding data in the Database.  There are some significant limitations inherent in both of these sources:  e.g., information only to the family level in the Field Guide, only scant description at the genus level in the Database.  So, whatever I've come up with probably only gets me into the ballpark.

That said, I found that almost 82 percent (45) of the 55 gastropod genera probably are, or were, carnivores (this includes 3 parasitic genera).  Given that the vast majority of snails in the Maryland Miocene were carnivorous, the moon shells clearly weren’t alone in their choice of food.

Who Drilled?

Interestingly enough, moon snails were not the only drillers included in the gastropod taxa that Vokes and his crew listed.  Though the Naticidae are considered a "major" drilling taxon among gastropods, they are joined in that designation by the Muricidae.  (Walker, p. 325.)  Members of that latter family are notorious drillers.  Indeed, today’s Urosalpinx cinerea carries the common name Atlantic Oyster Drill because it’s the scourge of oyster beds, drilling through the shells and feeding on the soft tissue inside.  Several genera belonging to the Muricidae family graced the waters during the Miocene here, such as Ecphora and Urosalpinx.

Perhaps Vokes' sole focus on the moon snails reflected the research available (then and now) on gastropod drilling in this time and place which has focused almost exclusively on the naticids.  I cannot believe that the Muricidae weren't drilling; that's one of the things they do.  Have I just overlooked the relevant research?

I thought maybe the fossil shells I have collected from the Chesapeake Bay could shed some light on this Naticidae and Muricidae disconnect.  The handiwork of these two families can be told apart:  holes drilled by Naticidae are beveled, wider on the exterior surface and narrower on the shell's interior, while those of the Muricidae are nearly straight.  (Alan R. Kabat, Predatory Ecology of Naticid Gastropods With a View of Shell Boring Predation, Malacologia, Volume 32, Number 1, 1990.)  The picture below of a bivalve shell from the St. Marys found on this same trip shows clearly that it fell victim to a moon snail.  The configuration of the hole tells it all.  This shell is from the species Dallarca idonea (cited in Vokes et al. as Anadara idonea.).

But, when I looked at my fossil shells for drilled holes that might have been made by Muricidae snails, there were none to be found, at least, none that I would, with confidence, attribute to them.  That's troubling because members of this family are drillers and they would have drilled here.  I have a thought about what might be partly at a work.  The Naticidae are infaunal feeders, which means they are operating partly or completely covered by bottom sediments, whereas the Muricidae are epifaunal, doing their thing on the sediments.  This makes a world of difference for the kinds of mollusks each type of snail is likely to encounter and feed upon.  Might that also influence the kinds of mollusk fossils commonly collected?  It's a whole new line of research for me (for another time and place).  In the end, I still come back to my conviction that the Muricidae were drilling here.

Other Dining Styles That Might Offend

I guess I was particularly dismayed by Vokes’ closing description of the drilled holes:  mute reminders of the unpleasant death suffered by the animal that formed the shell.  Is there some moral judgement here?  Some disgust at how the moon snail made, and makes, its living?  As far as I'm concerned, at that moment the authors stepped out of character, departing dramatically from the tone and the content of the rest of the volume.

What’s telling is that the Naticidae and other drillers certainly weren’t the only taxa likely to have engaged in feeding habits during the Maryland Miocene that might offend some sensibilities.  This came clear from some of Rehder’s descriptions of how those 29 extant genera included in his guide caught and consumed their food.  (And it doesn't excuse Vokes' closing words that these other feeding processes were unlikely to leave fossil traces.)

For instance, here’s what Rehder had to say about the Epitoniidae family (the Wentletraps), “[They] are carnivorous, preying on sea anemones, corals, and probably other coelenterates.  They feed by tearing off big pieces of tissues with their large, paired, filelike jaws.”  (p. 449.)

Or consider the Oliva genus which lived in these Miocene waters.  Still with us, it's part of the Olive Shell family (Olividae).  How do these family members gain sustenance in marine waters?  “Olive shells are scavengers or carnivores; they feed on bivalves and crabs, enveloping their prey with the foot and then carrying it under the sand to digest at leisure.”  (p. 579.)

One of my favorite approaches to feeding is practiced by the Conus genus whose fossil shells are found in the St. Marys formation (albeit rarely); the genus is part of the Conidae family (Cone Shell).  These gastropods have evolved a neat method of securing their next meal.  Their radula teeth have become harpoon-like spears that the animals launch at prey to capture them; then, through these teeth, the gastropods deliver a powerful, killing toxin, a poison that is quite dangerous for humans.  I wont even get into the practices of parasitic gastropods.

Sure, I may feel some twinges of revulsion at some of these methods of feeding, but I recognize how parochial that is of me.  After all, these are simply ways of making a living which have evolved because they enhance the ability of organisms to survive and reproduce.  They are the result of natural selection at work on the variation in living organisms.  As biologist Jerry A. Coyne has noted, “Selection is not a mechanism imposed on a population from outside.  Rather, it is a process, a description of how genes that produce better adaptations become more frequent over time.”  (Why Evolution is True, 2009, p. 117.)  So, there’s no morality to be imposed or found here, this behavior of the moon snails and other carnivorous gastropods just is.  Evolutionary biologist Stephen Jay Gould summed it up quite well, “[N]ature contains no moral messages framed in human terms.”  (Nonmoral Nature, Hen’s Teeth and Horse’s Toes, 1994, as reprinted in the Unofficial Stephen Jay Gould Archive.)

Sunday, August 30, 2015

Intriguing Chemistry of the Ecphora ~ Peeling Back the Layers

Shell fusiform, ventricose, with revolving costae; . . . .
~ T.A. Conrad, 1843
Research on the chemistry of the layers comprising the shell of the Ecphora, an extinct genus of gastropod, has led to some fascinating results.  My already strong sense of the beauty of this shell has deepened.  At the same time, the Ecphora seems to be in some sort of identity crisis; to me, its taxonomy is a frustrating and confusing mess.  Happily, there’s hope that the chemistry of its layers may also help address that.  Prompted by the acquisition of a particular Ecphora specimen (more on that later), I’ve begun to explore the literature on the Ecphora chemistry.  This post offers up some of what I’ve learned.

I am not alone in finding a singularly appealing grace in the flowing, intricate shape and red-brown to tan color of Ecphora shells.  Perhaps I’m stretching it a bit, but I think even naturalist Timothy A. Conrad’s turgid description of the genus’ shells (given above) manages to convey a sense of their aesthetic specialness.  (Proceedings of the Academy of Natural Sciences, p. 310, 1843.)  They are tapered at either end (think of a plump sewing spindle – fusiform), rounded out (ventricose), and covered with revolving (I’d prefer swirling) ribs (costae).

Though paleontologist Edward Petuch, whose fingerprints show up all though the Ecphora taxonomy, describes “ecphorine” shells as “bizarrely shaped,” he notes, in the same text, that they are prized for their “unusual shell sculpture, large size, and general intrinsic beauty.”  (Edward J. Petuch and Mardie Drolshagen, Molluscan Paleontology of the Chesapeake Miocene, 2009, p. 35.)

The specimen pictured below strongly exhibits the prototypical features of the ecphorine group of fossil shells – from size to shape to color (although the color of an Ecphora shell fades with exposure to sunlight, this specimen is grayer than many).

Ecphorine.  This adjective is being used by folks writing about the taxonomic group that includes the Ecphora genus partly because of the taxonomic muddle.  Unclear about whether several similar taxa are all in the genus Ecphora or some other genera?  "Ecphorine" covers a multitude of sins.  I don’t find a consensus out there about which are valid genera and what their relationships are.  Indeed, this group seems to be a battleground between lumpers and splitters.  My conservative (i.e., lumper) nature inclines me to follow Joseph G. Carter and his colleagues in the (possibly dated) paper titled Morphological and Microstructural Evidence for Origin and Early Evolution of Ecphora (Mollusca:  Gastropoda) (Journal of Paleontology, Volume 68, number 4, 1994, hiding behind a paywall).  In it, Carter et al. consider the Ecphora genus to be relatively broad in the species it encompasses and relatively old, dating from the early Oligocene.  As a result, in this post, I will use the generic name Ecphora expansively (and try to avoid the adjective ecphorine) to describe specimens sporting quintessential features of an Ecphora, including relatively large size, prominent (swirling) ribs, spindle-shaped body with a rounded and inflated midsection, and some red-brown to tan coloring.

I’m confident that the shell pictured above is from an Ecphora, but, given the taxonomic mess of this taxa, I will only suggest that it’s from E. quadricostata (Say, 1824).  I acquired this specimen from a dealer at a show.  Compounding the taxonomic confusion is the fact that I don't know exactly where this specimen was found.  The dealer would only say he "thought it was collected in Virginia."

Initially attracted by the specimen's size (it’s bigger than those I’ve collected on my own), I found another feature truly irresistible:  the chalky white layer that lines the interior of the shell.  It can be seen poking out of the spire at the top of the shell where the exterior grayish layer has broken away.  (Those initial swirls at the top of the gastropod’s shell are known as the protoconch, which, in shells of adult Ecphora, are typically broken off.)

Many of the Ecphora specimens in my collection exhibit some of that internal layer, but not to the extent of this one.  Indeed, the interior white layer is one of the defining elements of nearly all genera and species in the taxonomic group to which the Ecphora belongs.  Both layers (highlighted below) are composed of calcium carbonate (CaCO3) but the interior layer is in the form of aragonite, while the exterior is calcite.

Bearing the same chemical formula, calcite and aragonite differ in their crystalline structure.  Calcite is stable and, in contrast, aragonite is metastable meaning that it can, over a long period of time or under heat, be transformed to calcite.  In fact, the instability of aragonite greatly increases the chances that an aragonitic shell will dissolve in the fossilization process, leaving a mold or an internal cast.  It may also explains why many Ecphora are found with relatively little of the aragonite layer still present.

The current scientific thinking is that whether calcium carbonate precipitates in seawater as calcite or aragonite depends upon the ratio of magnesium ions to calcium ions in the water.  The lower that ratio, the more likely calcite is to form; the higher the ratio, aragonite or, perhaps, high-magnesium calcite (which results from some substitution of Ca ions with Mg ions) is the likely precipitate.  (David L. Chandler, Mystery Solved:  Why Seashells' Mineral Forms Differently in Seawater, MIT News Office, MIT News, March 2, 2015.)  And here, as a result, the tale takes a decided twist.

To my surprise, it turns out that over the course of the Phanerozoic Eon (beginning with Cambrian to the present), the planet’s seas have cycled between what are identified as “calcite seas” and “aragonite seas.”  At different times, the seas are more conducive to the precipitation of calcite or of aragonite.  Early and briefly in the Cambrian (which began 540 million years ago), we had aragonite seas that were followed by long-lived calcite seas.  In the Carboniferous Period (perhaps roughly around 340 mya – take this and all ensuing dates with a huge grain of salt), things shifted to a second phase of aragonite seas, which lasted until the mid-Jurassic (to roughly 170 mya).  These calcite seas endured until late in the Paleogene Period (to maybe 30 mya, during the early Oligocene).  From then until now, we’ve been in a third aragonite sea phase.  (There's a body of research on the driving engine for these changes, but it's not relevant to this post.)

The very crude dates provided above should not be taken to mean there were abrupt global shifts from one seawater chemistry to another.  Geologist Lawrence Hardie has suggested that these transformations may have occurred over 10-million-year periods.  (I derived these very soft dates by eyeballing graphics that appear in paleontologist Steven M. Stanley’s Earth System History, 2nd edition, 2005, p. 242, and in an article by Steven M. Stanley and Lawrence A. Hardie, titled Secular Oscillations in the Carbonate Mineralogy of Reef-Building and Sediment-Producing Organisms Driven by Tectonically Forced Shifts in Seawater Chemistry, Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 144, 1998, p. 6.  Paywall, I believe, for the latter.)

These shifts in seawater chemistry have significant implications for marine life, particularly influencing the kind of calcium carbonate secreted by less complicated organisms in the creation of their shells.  The proliferation of these simpler organisms is somewhat at the mercy of seawater chemistry; they thrive when the chemistry favors the kind of CaCO3 they secrete and decline when it does not.  As a result, for example, the changing patterns of aragonitic and calcitic reef-building follow the aragonite/calcite sea cycles.  In contrast, taxa that have greater biological control over their calcification processes can buck the shifting patterns in seawater chemistry to their long term benefit.  Stanley and Hardie note, “Taxa that engage in more sophisticated biomineralization cannot take full advantage of beneficial seawater chemistry in the same way [as the simpler organisms], but all else being equal, the carbonate productivity of these groups, such as the Mollusca, has been more stable throughout the Phanerozoic.”  (p.16.)

The most direct influence of seawater chemistry on those more complex organisms may have come when those taxa first appeared on the scene.  Biologist Susannah M. Porter has argued that the propensity for any major taxa to secrete either calcite or aragonite skeletons (i.e., shells for mollusks) is a function of seawater chemistry at the time when each taxa made its initial appearance.  She suggests that “when skeletons first evolved, natural selection favored the mineral easiest to precipitate” and the taxa remained locked into that mineral despite subsequent changes in the magnesium/calcium ion ratios.  (Susannah M. Porter, Seawater Chemistry and Early Carbonate Biomineralization, Science, Volume 316, Number 5829, June 1, 2007.)  Mollusks appeared during the early Cambrian when the seas were aragonite, so, according to Porter, it is not surprising that many mollusk taxa have shells composed of solely or mostly of aragonite, despite the several changes in water chemistry they have experienced since.

But what influence would seawater chemistry have on subsequent evolutionary change in a more complex organism, say, change like the addition of a different kind of calcium carbonate layer?  Case in point, the Ecphora.  According to Carter et al., in the paper cited above, Ecphora wheeleri, from the early Oligocene Epoch (which began about 34 mya), was the first species of the Ecphora genus, and its shells were composed entirely of aragonite.  (Reflecting the chaos of Ecphora scientific nomenclature, the name E. wheeleri seems to have fallen out of use, though any currently accepted name for the Oligocene species discussed by Carter et al. has successfully eluded all of my research efforts.)  Regardless, E. wheeleri (or whatever it’s now called) evolved into E. tampaensis (still a valid name, though Petuch renamed it Ecphorosycon tampaensis) which was the first species in the genus to secrete any calcite.  In that particular species, the calcite was limited to the ribs.  Subsequent Ecphora species sported a complete, external calcite layer.  The genus expired in the late Pliocene Epoch.  (This point of extinction is provided by the Paleobiology Database.  Petuch agrees with that being the end of the line for the ecphorine taxa (p. 37).)

Why evolve an outer calcite layer anyway?  Carter and his colleagues speculate that an external layer of calcite offered an evolutionary advantage to the Ecphora because it better resisted the acids used by other gastropod predators in attempting to drilling through the shell.

With Porter’s analysis in mind, I am intrigued that there was a shift from calcite seas to aragonite seas going on relatively close (if I can trust my squishy dates) to when the Ecphora was evolving a calcite outer layer.  That doesn’t seem a propitious time to do so.  Certainly the seawater change did not preclude the Ecphora from following the evolutionary path that led to an external calcite layer, though it might have made that more difficult.  I wonder, though, is the calcite layer possibly made of high-magnesium calcite which precipitates more readily in aragonite seas?  I’ve found nothing in the literature to answer that question.

Of course, the fact that the calcite layer did evolve is one of the key reasons that these beautiful shells are able to make it through the fossilizing process in the first place.  The layer plays another critical role:  it is responsible for maintaining the Ecphora shell’s distinctive color across millions of years.  Though aragonite over long periods of time can be transformed into calcite, most of the aragonite shells of the mollusks contemporaneous to the Ecphora fossilize to a dull, chalky white aragonite, that is, when they don’t dissolve completely.  In contrast, the color of Ecphora shells tens of millions years old can still stand out vibrantly.  Why?

In mollusk shells, aragonite or calcite crystallizes on matrices formed of proteins and polysaccharides which are often complemented with shell pigmentation coming from the mollusks’ diet.  For the fossil Ecphora shells, it’s the surviving calcite outer layer that preserves the color, and that color was a clue suggesting to paleontologists that, perhaps, that layer preserved other organic material.  Paleontologist J.R. Nance and his colleagues collected and broke down the outer layers of various Ecphora specimens found along the Calvert Cliffs in Maryland and then analyzed the material.  Earlier this year, they reported that they had found “protein-rich polymetric shell-binding material and associated pigments in [Ecphora] specimens as old as 18 Ma [million years old].”  (Preserved Macroscopic Polymeric Sheets of Shell-Binding Protein in the Middle Miocene (8 to 18 Ma) Gastropod Ecphora, Geochemical Perspectives Letters, January 20, 2015, p. 2.)  “In this context, intact proteinaceous shell-binding material in 8 to 18 Ma Ecphora represents some of the oldest and best-preserved examples of original protein observed in a fossil shell.”  (p. 7)

Finally, even more exciting, Nance et al. suggest their work raises the “possibility of amino acid sequencing and phylogenetic analysis through 10 million years of gastropod evolution.”  (p. 8)  I wonder if, thanks to that calcite layer, we might eventually bring some order to the Ecphora taxonomic confusion, order befitting the beauty of these fossil shells.

Friday, July 31, 2015

“Casual Collecting” ~ The U.S. Forest Service Hits Amateur Paleontologists with a Dictionary

When is “casual collecting” of fossils not casual collecting?  For that matter, when is a “sandwich” not a sandwich?  The answer is:  when a dictionary is used as a dispositive and authoritative source.

I’ve long thought it poor form to make a major point in an essay by using a dictionary’s definition of a word.  It’s somewhat akin to making a conclusive statement by quoting Wikipedia.  In other words, it shows a lack of imagination and, perhaps, research skills, as well as, ignorance or disregard of how the quoted authority is actually derived.  Yes, I’ve been guilty of incorporating a dictionary definition or two in the central part of a blog posting, but, that said, I do recognize that definitions of words differ from one dictionary to another, and that definitions change over time because dictionaries, particularly modern ones, are intended to reflect usage and common understandings.  They do not seek to present a definitive or authoritative guide to how a word should be used.

Not much is really lost when a blog post engages in this practice, but in other venues a great deal more may be at stake.  Take, for example, the recently published final regulations from the Department of Agriculture’s Forest Service (Federal Register, April 17, 2015) for its administration of the Paleontological Resources Preservation Act (Title VI, Subtitle D, Public Law 111-11).  These regulations have sent spasms of concern through the ranks of amateur paleontologists and fossil hobbyists.  And much, if not all, of that angst arises not from the regulations themselves, but from language in the accompanying (I think that’s the right word) “Section-by-Section Explanation of the Final Rule.”  In that Section-by-Section, the Forest Service turns to a dictionary to define the word “casual.”  Surely a misguided step.

So, what’s this all about?

PRPA is necessary and sound legislation enacted to protect paleontological resources on Federal land, replacing the previous patchwork of rules and policies with an overarching legal framework defining what can and cannot be done with such resources, and providing serious penalties for deliberate violations.  I’ve posted on this several times, most recently on June 7, 2013.  PRPA absolutely forbids commercial collecting of fossils on Federal land, while allowing “casual collecting” without a permit under specific conditions.  The law defines “casual collecting” in Section 6301(1):
The term “casual collecting” means the collecting of a reasonable amount of common invertebrate and plant paleontological resources for non-commercial personal use, either by surface collection or the use of non-powered hand tools resulting in only negligible disturbance to the Earth’s surface and other resources.  As used in this paragraph, the terms “reasonable amount”, “common invertebrate and plant paleontological resources” and “negligible disturbance” shall be determined by the Secretary.  [Note:  Reference to the “Secretary” should be read as to either the Secretary of the Interior or the Secretary of Agriculture, depending upon the federal lands involved.]
Under Section 6304(2) of the law, casual collecting without a permit is allowed on land of the Bureau of Land Management, Bureau of Reclamation, and the Forest Service “where such collection is consistent with the laws governing the managements of those Federal land and this subtitle.”

All well and good.  I’ve argued previously that PRPA actually is a boon to amateur paleontologists because it authorizes in law the “casual collecting” of  “common invertebrate and plant” fossils and also applies this to a somewhat broader sweep of federal lands than had been true under the previous policies and rules.  The key, for me, is my belief that, under this statute, what amateur paleontologists and hobbyists do is, in fact, “casual collecting.”  It’s important for this discussion to know  that I consider an “amateur paleontologist” to be someone who takes the avocational pursuit of fossils seriously, following a deliberate approach to collecting modeled, as best he or she can, on the practices of professional paleontologists.

During the many years of its legislative consideration, PRPA was the source of much handwringing and hyperbole within the amateur paleontology community sparked by concern that the law targeted amateur fossil collecting on Federal land for elimination, threatening violators with draconian penalties.  That concern about the law was, I thought and still think, unwarranted

But, now, I’m not so sure about the effect of the regulation writing process of the Forest Service.  The final regulations define “casual collecting” just as they were defined in the proposed regulations (Federal Register, May 23, 2013) and as they are in the law.  No problem there.

The Forest Service’s decision to add language defining “casual” to the text accompanying the regulations has created a problem for the amateur paleontology community.  Reflective of that concern is a piece that appeared in the 2nd issue in 2015 of the Janus, the newsletter of the North Carolina Fossil Club.  It’s titled Federal Forestlands Fossil Collection Ruling and Why it Matters and the author asserts that the Forest Service rule
is designed to end amateur fossil collecting (of any kind) on all Federal Forest Lands.
The writer goes on to claim that the “ruling is SPECIFICALLY written to address fossil INVERTEBRATE collection.  The 2009 Ruling already banned Vertebrate collecting” (capitalization in the original).

The message is clear and the tone just a bit shy of apocalyptic.  The perfectionist in me cringes at the erroneous references to a “2009 Ruling” (that’s the year the underlying legislation was signed into law) and its prohibition on vertebrate collecting (that ban was nothing new under prior Federal policies and rules, its codification in law is what was new).  But, getting beyond that and the various other errors in the article regarding legislative process and rule making, I think there is some fire beneath all of the smoke being raised.

In the Section-by-Section Explanation of the Final Rule, the Forest Service appears to be engaged in a process of trying to take away what the law provides for amateur paleontologists.  After reiterating the elements that the law stipulates constitute “casual collecting,” the Section-by-Section Explanation descends into a bit of dictionary-inspired madness:
The Department [of Agriculture] considers that in establishing the term “casual collection” [sic – the term actually established in law is “casual collecting”] rather than “amateur collection” or “recreational collection”, the Act intended that casual collection reflect the commonplace meaning of “casual”.  The commonplace definition of casual includes the elements “happening by chance; not planned or expected”, “done without much thought, effort, or concern”, and “occurring without regularity” (“casual”  2014.  (4 March 2014)).  (Federal Register, April 17, 2015, p. 21594.)
The Section-by-Section goes on to state
Consequently, the Department considers that casual collecting would generally be happenstance without intentional planning or preparation.  Development of criteria for reasonable amount and negligible disturbance reflects, in part, the view of casual collecting as an activity that generally occurs by chance without planning or preparation.  (p. 21594) 
Wait, wait.  In light of my idea of what an amateur paleontologist does in pursuit of fossils, we may be screwed.  Often, we plan, go into the field prepared, and are deliberate in our actions.  But, and it’s a sizeable but, none of the language in this Section-by-Section Explanation appeared in the proposed regulations in 2013 and their accompanying text.  So, it, essentially, appears out of nowhere and was not subject to any public comment.  Further, and very significantly, the law already defines what constitutes “casual collecting” and the legal elements are (1) collecting “a reasonable amount of common invertebrate and plant” fossils, (2) collecting for “non-commercial personal use,” and (3) collecting from the surface of the land or by means of “non-powered hand tools” without creating more than a “negligible disturbance to the Earth’s surface and other resources.”  That’s it, period.

Yes, the law specifically allows the Secretaries to define certain phrases in the definition, but not the term “casual collecting” or the word “casual.”

Admittedly, I don’t know what legal force this Section-by-Section Explanation really has when it comes to enforcing the Forest Service’s regulations, either by the agency or in a court of law.  Perhaps little, perhaps a great deal.  Regardless, it’s highly troubling and it’s wrong.

Assuming that this language reflects how the Forest Service will actually approach amateur paleontologists collecting on its land, then, as far as I can see, the Service is going out of its way to limit the collecting that can take place in such a way that violates the spirit, intention, and plain language of the law.  Turning to a dictionary’s definition of what “casual” means is nonsensical and fraught with problems.  Different dictionaries may define “casual” in different ways and a dictionary may provide several senses for a word, as the Merriam-Webster Dictionary website, cited by the Forest Service, does for “casual.”  It offers three different senses of the word “casual,” each of them conveying something slightly different.  The Forest Service’s Section-by-Section Explanation picks from all of those senses in its selection of “phrases” that it asserts define “casual.”  Yes, one of the Merriam-Webster senses focuses on chance and the unexpected, but another, separate sense is based on the idea that “casual” can be used to describe something that does not occur with regularity, that is occasional.

My Webster’s Seventh New Collegiate Dictionary (1963), which is one of two I have immediately at hand (it’s a falling-apart, hardcover book that just happens to be around my summer cottage) has this to say about how to use the different senses of a word:
The best sense is the one that most aptly fits the context of an actual genuine utterance.  (p. 12a)
Ah, context.  That’s missing from what the Forest Service did in its effort to define “casual.”  At the outset, there is the context of the legal definition itself which is dispositive, as far as I can see.  It’s easy to identify what would not constitute casual collecting – the collection of an unreasonable amount of fossils, the collection of vertebrate fossils or fossils from rare invertebrates or plants, the collection of fossils for commercial purposes, or the collection of fossils in such a way that the land is disrupted.  The law intends to preclude each of those actions.

Perhaps even more damning for the Forest Service is the internal inconsistency that its definition of “casual” has with the language of the law itself.  The Forest Service holds that the drafters of the law intended “casual” to mean, among other things, “happening by chance; not planned or expected” or “done without much thought, effort, or concern.”  If that’s true, then, why would the law permit “casual” collectors to use “non-powered hand tools”?  The Forest Service regulations define such tools as “small tools that can be easily carried by hand such as geologic hammers, trowels, or sieves, but not large tools such as full-sized shovels or pick axes.”  How would such allowable tools come to be brought onto Forest Service land by collectors in the first place, if not deliberately, through planning, and with forethought?

Did the Forest Service do a thorough search through the legislative history to determine whether “casual collecting” was intended to preclude amateur collecting?  The appropriate legislative history should be seen as really stretching back through several Congresses because that’s the time span in which the legislation was considered.  I went back through just the 111th, 110th, and 109th Congresses to see what might turn up.

What doesn’t turn up is any explicit statement that “casual collecting” was not intended to describe what most amateurs and hobbyists do.  Rather, in some instances, it’s fairly clear that the phrase is broadly construed by the Members who sponsored the bills and by officials in the Executive Branch.  For instance, in the 109th Congress, when Senator Akaka introduced S. 263, the Paleontological Resources Preservation Act which had a definition of “casual collecting” that mirrors what was ultimately enacted in 2009, he stated:
The bill acknowledges the value of amateur collecting and provides an exception for casual collection of invertebrate fossils, but protects vertebrate fossils found on Federal lands under a system of permits.  (Congressional Record, February 2, 2005, p. S891.)
Perhaps Senator Akaka intended to distinguish “amateur collecting” from “casual collection,” but I don’t think so, I believe he was equating what amateurs do with casual collecting.

In the next Congress, the Senate Committee on Energy and Natural Resources approved S. 320, the Paleontological Resources Preservation Act and reported it with language identical to that in P.L. 111-11 defining “casual collecting.”  The Senate Committee Report 110-18, to accompany S. 320, included, among the Executive Communications for the legislation, a statement by Christopher Kearney, Deputy Assistant Secretary for Policy, Management and Budget of the Department of the Interior.  (This statement was actually presented a couple of Congresses earlier in testimony on S. 546 that included the same language regarding “casual collecting.”)  Kearney had this to say:
One exception to the permitting requirements under S. 546 is for casual collection of certain paleontological resources for personal, scientific, educational and recreational uses.  This important provision would authorize the Secretary to allow the public to casually collect common invertebrate and plant fossils without a permit on certain federal lands.  In other words, under this bill, visitors to BLM [Bureau of Land Management] lands who enjoy paleontology as a hobby could continue to collect and keep for their personal use a wide variety of plant and common invertebrate fossils.  The casual collection of such fossils can be an important component of the public’s enjoyment of some federal lands and is generally consistent with scientific and educational goals.  (p. 6)
The BLM has always been supportive of fossil collecting by amateurs, so it’s not surprising that Kearney’s statement reads as it does.  Significantly, he finds that the legislation permits “casual collection” by those who “enjoy paleontology as a hobby.”  Where’s the notion that “casual” means happening by chance or unexpectedly?  That simply wasn’t an aspect of the understanding of what “casual” meant to this governmental official testifying on the legislation.

Finally, with regard to the Bureau of Land Management, which has not yet issued even its proposed regulations for PRPA, I take some solace in the concluding comments in the North Carolina Fossil Club piece.  The author reports on a conversation she had with “the head paleontologist of the Bureau of Land Management” who acknowledged that the Forest Service language was “unfortunate.”  The author of the piece asserts that “the BLM folks seem to be more open to the Amateur/Avocational community and they intend for their wording to be different.”

I would hope so.  The language of the law is straightforward; its definition of “casual collecting” requires no ad hoc definition of the word “casual.”  How does the Forest Service define “absurd”?

The case of the “sandwich” definition is a wonderful example of why what the Forest Service has done in relying on a dictionary to determine legislative intent is absurd.  There’s a fascinating literature on the use of dictionary definitions in court opinions, primarily at the level of the U.S. Supreme Court.

[Note:  If you came to this post to read about PRPA, you may want to stop here.]

Lawyer and reporter Adam Liptak, writing in the New York Times, asserts, “In the last two decades, the use of dictionaries at the Supreme Court has been booming.”  (Justices Turning More Frequently to Dictionary, and Not Just for Big Words, June 13, 2011.)  Citing a Marquette Law Review article, Liptak notes that in the first decade of the 21st century, Supreme Court justices turned to dictionaries in 225 opinions, defining 295 words.  Fifty years earlier, in the decade of the 1960s, dictionaries figured in just 16 opinions, defining 23 words.

Much of the recent blame for this trend can be laid at the feet of the “textualists” on the Court, Antonin Scalia, among them.  Law professor Ellen P. Aprill describes “textualism” as giving “particular attention to the statutory language” involved in a case.  (The Law of the Word:  Dictionary Shopping in the Supreme Court, Legal Studies Paper No. 2006-12, Loyola Law School, 1998, p. 278)  Instead of turning to the legislative history of a statute, textualists often employ a different tool to parse the meaning of words used in statutes:  the dictionary definition.  Aprill provides a detailed examination of why dictionary definitions are often decidedly unreliable and inappropriate in a legal context, concluding:
Their purpose of giving readers and speakers approximate meanings of words so that they begin to understand the meaning of the word in context makes dictionaries ill-suited for determining the meaning of a particular word in a particular statute.  (p. 334)
One of the funniest and most damning instances of using a dictionary definition in a case centers on a decision rendered in 2006 by Judge Jeffrey A. Locke of the Massachusetts Superior Court in the case White City v. PR Restaurants.  The case hinged on whether White City Shopping Center had violated the “sandwich” exclusivity clause in its lease with PR Restaurants for the operation of a Panera Bread Restaurant in the shopping center.  That clause stipulated that White City couldn’t enter into a lease with any other entity with a significant portion of its annual sales (over 10 percent) coming from the sale of sandwiches.  The crux of the legal debate was whether the “tacos, burritos, and quesadillas” that a Qdoba Restaurant would be selling under a lease with White City should be considered “sandwiches.”  Since the exclusivity clause did not define “sandwich,” Judge Locke turned to the New Webster Third International Dictionary which defined a "sandwich" as “two thin pieces of bread, usually buttered, with a thin layer (as of meat, cheese, or savory mixture) spread between them.”  The word “sandwich,” determined Judge Locke, did not include burritos, tacos, or quesadillas because those foods involved the use of “a single tortilla and stuffed with a choice filling of meat, rice, and beans.”  Though, as I read it, the heart of his decision rested on his interpretation of this dictionary definition, Judge Locke also noted that PR Restaurants could have defined sandwiches in the exclusivity clause and chose not to, even though at the time it was negotiating its lease, it was aware that nearby restaurants sold burritos, tacos, and quesadillas.

The White City decision is saluted by Justice Antonin Scalia and Bryan Garner in their book titled Reading Law:  The Interpretation of Legal Texts (2012).  Richard A. Posner, Judge on the U.S. Court of Appeals for the Seventh Circuit, in a scathing review of the book for the New Republic titled The Incoherence of Antonin Scalia (August 24, 2012), reserves some choice words for Scalia and Garner’s treatment of White City.  They posit that the entire case was decided on the basis of the dictionary definition.  Posner disagrees, noting, as I did above, that Locke put the definition in the context of the drafting of the exclusivity clause.

But here’s where the fun really mounts and a critical point gets made about reliance on dictionary definitions.  Posner posits, “[T]he court got the definition wrong.”  He observes, 
A sandwich does not have to have two slices of bread; it can have more than two (a club sandwich) and it can have just one (an open-faced sandwich).  The slices of bread do not have to be thin, and the layer between them does not have to be thin either.  The slices do not have to be slices of bread:  a hamburger is regarded as a sandwich, and also a hot dog – and some people regard tacos and burritos as sandwiches, and a quesadilla is even more sandwich-like.  Dictionaries are mazes in which judges are soon lost.  A dictionary-centered textualism is hopeless.  (Emphasis added.)
Amen to that.  Sadly, the Forest Service is also lost in a dictionary maze.
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