Thursday, January 31, 2013

Citizen Science ~ Butterflies, Ships, and Science (Maybe)

Even after all that has been learned about it in recent years, the monarch butterfly (Danaus plexippus) remains marvelously mystifying.  Weighing just roughly half a gram, some of these creatures make an annual migration of thousands of miles from the eastern U.S. and Canada to the Transvolcanic Range of central Mexico where they overwinter.  Hard to get more amazing than that.  I recently read Sue Halpern’s book, Four Wings and A Prayer:  Caught in the Mystery of the Monarch Butterfly (2001), a superb piece of provocative and inspiring nature writing telling a story populated with wonderful butterflies, as well as a colorful cast of men and women (some in the human cast are more wonderful than others).

(I photographed this monarch in the Smithsonian Natural History Museum's live butterfly exhibit.)

I was particularly struck in Halpern's account with the role of the amateur, the citizen scientist, interacting directly with the butterfly and with scientists studying it.  In the early 1950s, when the destination and fate of the millions of monarchs seen traveling through the fall skies from the northern reaches of the U.S. and Canada were still a profound mystery, zoology professor Fred Urquhart at the University of Toronto and his wife Norah recruited volunteers in an effort to tag monarch butterflies and track their journey.  Some 3,000 volunteers responded and the Urquhart network generated data until the early 1990s.  I recently saw the IMAX 3D movie Flight of the Butterflies which tells of the search for the monarchs’ overwintering site; it presents the Urquharts as the unblemished heroes of the tale.  As Halpern suggests, this is not the only way to tell the story.  Regardless, the Urquhart network produced a wealth of useful data.  And the effort continues.  For instance, Monarch Watch, a great resource supporting the monarch, has reported the recovery of over 16,000 of its tags between 1992 and 2011.

There currently is a buzz about the exploding universe of what’s labeled “citizen science,” in which myriad volunteers provide support to scientific projects.  Citizen science, per se, has come under academic study, generating various definitions of what it is.  I like the definition of "public participation in scientific research" offered by Cornell Lab of Ornithology's Citizen Science website.  Yes, it's a bit circular because the phrase "citizen science" is in this definition but it captures the essence of what this activity is (or should be) about:
The growing field of public participation in scientific research (PPSR) includes citizen science, volunteer monitoring, and other forms of organized research in which members of the public engage in the process of scientific investigations:  asking questions, collecting data, and/or interpreting results.
Press coverage has been enthusiastic with Hillary Rosner’s piece in Scientific American (Data on Wings, February 2013) just a very recent example.  At this end of this post, I take Rosner to task for certain claims in her article, but first a bit of history and context.

Citizen Science ~ Past

As the butterfly tagging suggests, this is really old news.  Citizen science projects in this country have a more than two hundred year history.  Writer Jeffrey P. Cohn in a piece titled Citizen Science:  Can Volunteers Do Real Research?  (BioScience, March 2008), posits, “The practice goes back at least to the National Audubon Society’s annual Christmas bird count, which began in 1900.  About 60,000 to 80,000 volunteers now participate in the that survey.”  But such projects date back still farther.  Rosner cites the meteorology network fashioned by Joseph Henry, the Smithsonian’s first Secretary in the l840s.  Historian Daniel Goldstein writes that “American participation in European-dominated [science] networks dated back at least to the previous century [18th century], and they [Americans] had been building their own correspondence networks for decades.”  (“Yours for Science”:  The Smithsonian Institution’s Correspondents and the Shape of Scientific Community in Nineteenth Century America, Isis, December 1994, note 8.)

I would include among the historical antecedents to today’s rush of citizen science projects the correspondence network that Spencer F. Baird maintained from his position as the Smithsonian Institution’s Assistant Secretary of the Natural History Department (a position to which he was appointed in 1850).  Purists may argue that it wasn’t citizen science at all because there wasn’t a specific scientific research project being supported.  That’s true, but the reaching out by this scientist to the broader public, seeking to engage it in fulfilling (often in very hands-on ways) the scientific mission of this institution seems, to me, to make it at least a pretty close cousin to citizen science.

Upon his arrival in Washington, Baird, an ornithologist and natural history professor at Dickinson College, expanded the institution’s existing correspondence activities into a nationwide web of correspondents that helped to build the Smithsonian’s collections of natural history specimens, and to support science across the country.  Baird was a collector of the first order who shipped his own collections to Washington in two boxcars. (Baird as Assistant Secretary and the Growth of a Dream, Smithsonian Institution Archives.)

(Baird is seen above in 1845 when he was Professor of Natural History at Dickinson College.  It is part of the collection of the Smithsonian Archives and was downloaded from its website.)

The assistance moved both ways in the network, with personal correspondence from Baird, books, help with identifications, among other support, flowing out from Washington.  This was no small undertaking for the assistant secretary.  Most of the over 3,000 letters that Baird personally wrote annually early in his tenure were to correspondents in his network, and the burden only grew over time.

I am particularly interested in Baird’s enterprise because of what it says about the widespread enthusiasm with which mid 19th century America embraced science.  The vast majority of the correspondents were committed at some significant level to doing, and learning about, natural history.  (Goldstein does note that a small subset of correspondents apparently had little interest in natural history.)  Given that the professionalizing of the sciences was still largely in its infancy, it’s probably not surprising that the network reached well beyond those for whom some aspect of natural history might be the basis of their careers.  The breadth of its reach was impressive, embracing a broad group of people from many different walks of life with an interest in natural history.  They were not “a small class of highly educated urban male professionals.  The doctors, professors, and government scientists were complemented by large numbers of farmers, tradesmen, clerical workers, and manual laborers. . . . [M]ost of the respondents [to a survey of correspondents] were probably not among the minute fraction of the American population with college degrees.”  (Goldstein, “Yours for Science,” p. 577.)

I love the image of a farmer exchanging letters with an assistant secretary of the Smithsonian about, say, a collection of insects, perhaps even sending some specimens to Washington.

Citizen Science ~ Present

What the Urquharts did, engaging a cadre of non-scientists to work on a specific scientific endeavor (tagging monarchs), has now become more common, technology-driven, and conducted on a scale not previously seen.

In the name of citizen science, I’ve time traveled.  For a very brief period last year, I was a lieutenant aboard a British naval sloop sailing out of Queenstown, Ireland.  It was February, 1917, and the bloodletting of World War I would continue its awful course for more than a year.  This year, as I try to reengage in this time travel, I’m on board the gunboat U.S.S. Concord in 1891.

(This photo was taken between 1890 and 1901, and was downloaded from the Library of Congress' Prints and Photographs Online Catalog.)

The context, in both instances, has been the Old Weather project which is mining old ships’ logs to amass weather data in an effort to improve the computer models used to analyze weather patterns and future climate.  My responsibility, as is that of every volunteer engaged in the project, has been to read scans of the original ships’ handwritten logs and transcribe the location of the ship and the weather data appearing in the log, including the direction of the weather, its force, the barometric pressure, the temperature (measured in several different ways), the state of the sky (nature of the clouds, extent of cloud coverage), and the kind of precipitation (if any).

The project, which began with the logs of vessels in the British Navy during WWI, and now includes the U.S. Navy in the late 19th and early 20th centuries, has the support of several governmental agencies, museums, universities, historical societies, and other institutions.  These include the U.S. National Archives, NOAA, the UK’s Met Office (national weather service), National Maritime Museum (UK), and the University of Oxford.

The power of the crowd has been put to work transcribing these logs in part because computers are ill equipped to read the handwritten log entries (frankly, it’s not always easy for this human to read the writing either).  Each log page is transcribed multiple times by different participants in an effort to weed out errors.  As of May 2012, a million log pages had been transcribed.

It’s a worthwhile project, with the resulting data made available not only for climate and weather studies, but also for historical and geographic research, among other uses.  There are some other interesting applications.  Using the logs of British naval vessels during WWI, the The Guardian posted an amazing digital representation of the changing locations of these vessels during each month of the war (at this link).  Okay, it’s not climate science, but it’s a spellbinding reflection of the course of the war.

Old Weather is part of the Zooniverse’s array of projects which began in 2007 with Galaxy Zoo using "crowdsourcing" to classify galaxies.  It has expanded to include a wide range of different computer-based projects enlisting lay people in scientific efforts that range from exploring the Moon’s surface to classifying cyclone data, from identifying animals in millions of pictures taken in the Serengeti to categorizing sounds made by whales.  Zooniverse lays claim to nearly 800,000 volunteers at work on its projects.

Citizen science, citizen scientists.  The growing interest in these activities arises, in part, because they can be greatly facilitated by computer technology linking the efforts of thousands, if not hundreds of thousands, of individuals at work on data numbering in the millions.  Yet, lest one conclude that all current citizen science projects are technology driven and tether volunteers to their computers, there are many, like butterfly tagging, that draw participants outside where they run the risk of getting their hands dirty.  The Citizen Science Central website offers links to a broad array of projects that run the gamut.

In her Scientific American article, Hillary Rosner writes of the potential effect citizen science projects (of all stripes) have of informing a broad swath of the population about difficult scientific issues, and drawing them into a search for solutions:

Cumulatively, . . ., the spread of citizen science may amount to something much larger, signaling a shift in the way scientists and the public think about the enterprise of science.  A new age of participatory science is taking shape at the exact moment when society may need it most – as we cope with complex problems such as climate change that require both copious data and an engaged citizenry.  (Data on Wings, Scientific American, February, 2013, p. 70)

She asserts, “One of citizen science’s most important contribution may ultimately be to spread scientific literacy by giving laypeople direct contact with the process of science.”

It’s a heady assessment and I think she claims too much, at least for some of these projects.  How connected are their volunteers to the process of science or to the science into which their labor feeds?  I wish she had cast a more critical eye on differences among them and considered which are more likely than others to make real contributions to scientific literacy, and why.

Take my own, very brief work on the Old Weather project.  Ah, the dreaded “sample of one.”  I understand that what I am doing with the ships’ logs fuels analysis of weather and climate patterns over time, but what I have been learning about are the old ships and the glimpses of history that the logs afford me, not the climate science on which the project is focused or the scientific process that's at work with the data being generated.  Is that my fault?  Perhaps, but, in this instance and with this specific volunteer, just doing the data gathering work doesn't guarantee any exposure to the scientific process, any growth in scientific literacy.

Tuesday, January 22, 2013

Family Matters ~ Peabody Museum of Natural History

On a recent trip to Connecticut to visit family, I slipped away and spent part of an afternoon at Yale University’s Peabody Museum of Natural History.

I expected to find a shrine to Othniel Charles Marsh (1831 – 1899) because, without him, there would be no museum.  Though evidence of Marsh’s abundant contributions to paleontology mark the museum, there is no hagiolatry here, thankfully.  A large portrait, prominently displayed, does honor George Peabody (1795 – 1869), the wealthy businessman, banker, and philanthropist whose gift financed this museum.  His generosity extended to numerous other scientific and cultural institutions as well, among them Harvard University’s Peabody Museum of Archaeology and Ethnology, and Johns Hopkins University’s Peabody Institute (a preeminent music conservatory).  He was also committed to improving housing for the poor in his adopted Britain where he spent the last three decades of his life.

Of course, for the museum, it made all the difference that Peabody and Marsh were family – Peabody’s sister Mary was Marsh’s mother.  She died when Othniel was two, and Peabody assumed a central role in supporting his nephew.  In 1862, Marsh, who by then had earned a master’s from Yale’s Sheffield Scientific School at Yale, skillfully planted the seed with his uncle for the endowment of scientific research at Yale, a seed that bore fruit in 1866 with a generous gift of $150,000 for the founding of the Museum of Natural History.  Marsh apparently was responsible for guiding Peabody’s philanthropy toward the sciences in general, not only at Yale.  (This is Franklin Parker’s argument in George Peabody:  A Biography, 1995, portions available on line.)  Not coincidentally, in that same year, 1866, Marsh was appointed Professor of Paleontology, the first such professorship in the U.S.  (The museum’s website is an excellent source for more information on Marsh and the history of the museum.  Very useful and rather balanced in its assessment of Marsh is the museum’s own publication by Mark J. McCarren, titled The Scientific Contributions of Othniel Charles Marsh:  Birds, Bones, and Brontotheres, 1993.)

Marsh, a decidedly prickly personality, went to on to become, in McCarren's words, “the greatest American paleontologist of the nineteenth century with only the brilliant and energetic Edward Drinker Cope being worthy of comparison.”  (McCarren, p. 1.)  Cope (1840 – 1897) and Marsh entered into a bitter, heated competition in pursuit of fossils of new species, particularly dinosaurs, in the western reaches of the U.S.  The so-called Dinosaur Wars or Bone Wars have been touched on in previous posts in this blog (including one at this link).

Marsh’s unflagging pursuit of vertebrate fossils in the west, financed in large part by Uncle George’s money, led to the amassing of a huge collection, some elements of which are on display in the museum.  In passing, I would note that the Smithsonian’s National Museum of Natural History benefited greatly from the fallout of the Marsh vs. Cope struggle, with significant parts of Marsh’s collection ultimately coming to rest in the NMNH.

Greeting a visitor to the Peabody Museum is a life-size statue of Torosaurus latus which stands outside on a 13 foot tall granite pedestal.

“Greeting” might not be the right word.  I was tempted to write that this ceratopsian (horned) dinosaur “stands guard” and the animal certainly is formidable, but that may not be appropriate given that T. latus was a plant eater.  Still, vegetarians can be aggressive.  More on Torosaurus in a moment.

The present museum building was opened in 1924, replacing the original structure that stood from 1876 to 1917.  It is only one of several that presently house the university’s natural history collections.  Much of the interior of museum that is open to the public is intimate and dark.  Movement from floor to floor is by stone stairways lit by arched windows.  All of which fits my image of a medieval university building or, perhaps, a monastery.

(The tentacles of a model of giant squid, suspended over the opening hallway, cut across the windows in the photo above.)

The centerpiece of the museum is the Great Hall where the dinosaurs live.  Dominating the room is an Apatosaurus (the dinosaur formerly known as Brontosaurus).

The walls are lined with fossil displays, while The Age of Reptiles mural, painted by Rudolph Zallinger, runs above the exhibits along one wall.  The mural is lost on me, partly because of its location (high on its wall and, so, immune to close study) and partly because I worry that murals that are several decades old (this one was begun in 1943) may not reflect the best thinking about the depicted flora and fauna.  I wonder whether I’m also reacting negatively because the museum makes a big deal about how the mural is off limits for photography and the guard cautioned me when I appeared to be photographing it.  (Actually, I was, though unintentionally.  Honestly, I deleted those shots.)

In contrast, I was awed by the huge piece of chalk that stands against one wall.  Embedded in the stone is what its plaque describes as “one of the most complete mosasaur skeletons ever found.”  These remains of a Platecarpus tympaniticus are as they were uncovered in Kansas in 1877.  Amazing.

But, frankly, the most compelling feature in the Great Hall is the display of several ceratopsian skulls that occupies the far wall.  It’s a spellbinding collection of enormous horned skulls.  The photograph below shows a tandem of skulls; that in front is from a Triceratops and that behind from a Torosaurus.  (The latter, measuring, I believe, some eight feet in length, was found by John Bell Hatcher in 1891.  The inspiring Hatcher is the subject of a previous post.  Is that a bit of mural in the picture?)

The plaque describing the Torosaurus is interesting for a couple of reasons.  First, it contradicts information regarding the derivation of the name provided by the museum on its website.  The plaque states unequivocally that the name “comes from the Greek, meaning Bull Reptile,” whereas the website, acknowledging confusion in some circles over the source of the name, posits (quite persuasively) that Marsh, who named the beast, focused on the large oval holes (parietal fenestrae) in its frill.  Thus, the Greek root toreo, meaning “perforate, pierce,” is most likely the name’s origin.  It's a "perforated lizard."  Indeed, in 1892, Marsh wrote, “The open perforations in the parietal which have suggested the name Torosaurus, readily separate this genus from all the gigantic species hitherto known in the Ceratopsidæ, but may perhaps be found in some of the smaller and less specializes forms, from lower horizons of the same formation.”  (O.C. Marsh, The Skull of the Torosaurus, American Journal of Science, January 1892, p. 82.)

As for my second point of interest with the plaque, it's a matter of omission.  It emerged as I explored the little tussle over origins of the name a bit further, and stumbled on the more fundamental debate going on within some portion of the paleontological community over this particular dinosaur, a debate that has all the hallmarks of a family argument.  It has rabidly held positions, the questioning of motives, snide remarks and innuendo, with little evidence, so far, of anyone ceding ground.  Perhaps, as will be clear, it's not surprising the plaque makes no mention of this debate.

The Torosaurus skirmish began in 2010 when Jack Horner and John Scannella of the Museum of the Rockies published a paper in which they asserted that, heretofore, paleontologists had been confusing adult and juvenile specimens within the same genus when they distinguished between Torosaurus and Triceratops.  According to this hypothesis, the Torosaurus is actually just the Triceratops grown up.  They're all in the family or, more precisely, they're all in the genus.  This argument asserts that the apparent skeletal differences between the two genera reflect changes in the animal as it matured.  Horner and Scannella theorize that these changes took place rapidly as the animal reached adulthood, e.g., the parietal fenestrae opened up very late in the animal’s development.  If correct, the separate genus of Torosaurus would be laid to rest.

But, not so fast.  Nicholas R. Longrich and Daniel J. Field of Yale University have come to Torosaurus’ rescue, asserting in a recent paper that the Horner-Scannella hypothesis fails because not all of the Torosaurus specimens appear to be more mature than the Triceratops specimens, and there is an absence of intermediate specimens between the two (as would be expected if one matured into the other).  These are two of the three conditions they contend would have to be met for “the Torosaurus is Triceratops hypothesis” to stand.  (They agree that the other condition, similar distribution of the two purported genera in terms of geography and stratigraphy, is met.)

In a New York Times article on the fight, Longrich is quoted as saying, “Horner’s got an agenda. . . . He has this hit list of dinosaurs that he’s trying to get rid of.”  That Horner and Scannella seek to dethrone a Peabody Museum symbol may have played a role in their robust response, acknowledge the Yale researchers.  “That’s not to say we were biased,” Field noted.  For his part, Horner commenting on bone fusion, a key element in the Longrich/Field analysis for determining maturity (the skulls of less mature individuals may be less fused), said, “Bone fusion, as far as we’re concerned, doesn’t say anything.”

Making this debate over the two genera even more like the tail end of a long family dinner is that, at its core, it’s a manifestation of a longstanding conflict that has punctuated many family gatherings.  Within paleontological ranks, this is the classic struggle between lumpers and splitters, that is, between those whose inclination is to merge taxa and those who are prone to identify new taxa.

(The Torosaurus skirmish can be followed in various sources, including J.B. Scannella and J.R. Horner, Torosaurus Marsh 1891 is Triceratops Marsh 1889 (Ceratopsidae: Chasmosaurinae):  Synonymy Through Ontogeny, Journal of Vertebrate Paleontology, July 2010; Longrich and Field, Torosaurus Is Not Triceratops:  Ontogeny in Chasmosaurine Ceratopsids as a Case Study in Dinosaur Taxonomy, PLoS ONE, February 29, 2012; John B. Scannella and John R. Horner, ‘Nedoceratops’:  An Example of a Transitional Morphology, PLoS ONE, December 14, 2011; Theodoric Meyer, Triceratops’ Quiet Cousin, the Torosaurus, Gains New Legitimacy, The New York Times, March 5, 2012; Carol Hsin, Peabody Icon May Need a Name Change, Yale Daily News, October 22, 2010.)

There’s far more to the museum than I’ve touched on, much of it interesting and well done (Birds of Connecticut, and the Hall of Minerals, for example), though my hopes for the Connecticut Fossils exhibit were dashed when it only confirmed my own understanding of a dearth of such fossils.  The sad truth is that Connecticut is, as the exhibit describes, “one of the least fossiliferous states in the U.S.”

At visit's end, I eased through the front doors of the museum into a cold winter afternoon, walked to my car, and drove off to rejoin family.

Saturday, January 12, 2013

Strange Small Eruptions

Horatio         In what particular thought to work I know not;
     But in the gross and scope of my opinion,
     This bodes some strange eruption to our state.
~ Hamlet, Act I, Scene I

I haven’t thought through the precise implications of my fascination with the world of microfossils, but in general I sense that it “bodes some strange eruption to our state.”  Perhaps not tragedy, but certainly change in behavior. 

Case in point, the fossil shell pictured below.  It prompted new behavior and led to some small eruptions (though nothing really earthshaking).

In a recent post, I initially identified this shell as coming from an Ecphora tricostata.  I have reason to think something’s rotten in my analysis, given the location where it was found (Scientists’ Cliffs), the formation I think it came from (Calvert), and the likely age of the material (Middle Miocene – some 16 to 12 million years old).  The definitive study of the stratigraphy of this area posits that E. meganae, not E. tricostata, is found in these portions of the Calvert Formation, but my fossil favors the latter more than the former.  (Lauck W. Ward and George W. Andrews, Stratigraphy of the Calvert, Choptank, and St. Marys Formations (Miocene) in The Chesapeake Bay Area, Maryland and Virginia, Virginia Museum of Natural History, 2008.)

It’s symptomatic of my current obsession with the micro that, rather than continue to puzzle over the identification of this Ecphora, I am now consumed by the gray clay matrix that surrounded and filled the shell.  Some three months ago, when I prepared the fossil, I ignored some expert advice and removed the matrix from what, unfortunately, turned out to be a rather fragile shell.  In the process, the internal, central pillar (columella) broke free.  A shame.

But, in a move that I recognized at the time as somewhat quixotic and strange, I bagged the matrix I removed from the shell, slapped a label on the bag, and set it aside.

A couple of weeks ago, I came across the bag and thought, “What the hell, let’s see what’s in here.”

I wont go through the tedious details of my amateurish handling of these few grams of Miocene material, except to say that it involved one percent solutions of Calgon (in water), lots of soaking, lots of sieving, but no baking.  And still it’s plagued with lumps.  (The comedy of errors that is my preparation of material for microfossil searching is described in painful detail in a previous post.  I’ve added some scientific sieves to my equipment, providing a patina of the professional to my inherently sophomoric efforts.)

There was something of the miraculous when, under the microscope, from the gray miasma of this matrix, intricate microfossils made their first appearance, ghosts of minute Miocene fauna.  Amazing what now gets my heart racing.

From within that fractured Ecphora came a flood of foraminifera shells, accompanied by a much  sparser scattering of ostracode shells.  Remarkably, despite several hours of picking, I haven’t exhausted this sample yet.  At this juncture, the critical limit to my time before the microscope is what my hunched over shoulders can bear.

Though I am retrieving foraminifera shells in many different and complex shapes, it’s a couple of shells from the ostracodes, those miniscule crustaceans, that have captured my imagination for the moment.  These two fossils are ornate, exploding with blunt and pointed spines.  Among the many spines are some that, upon closer examination, form three curved rows marking portions of the length of each shell.

These two specimens are both about 0.8 mm long.  Ostracodes have right and left valves hinged at the dorsal edge (top edge of each specimen in the photograph).  The top specimen shown is a right valve, the bottom one is a left valve (the valves are certainly from two individuals).

I’ve identified this Miocene ostracode as Actinocythereis exanthemata (Ulrich and Bassler, 1904).  My primary source for this identification is Richard M. Forester’s paper titled A Systematic Revision of the Ostracode Species Described by Ulrich and Bassler and by Malkin from the Chesapeake Group in Maryland and Virginia (U.S. Geological Survey, Geological Survey Professional Paper 1128, 1980, p. 11 and plate 3, figures 7 and 8).

In 1904, E.O. Ulrich and R.S. Bassler, wrote the initial description of this species for the Maryland Geological Survey’s Miocene: Text (Volume I, 1904, p. 117-118).  They contributed the Ostracoda discussion to the Systematic Paleontology portion of the book.  Amid their lengthy characterization of this fossil, which they named Cythere exanthemata, is a pithy phrase that nicely captures the essence of their description – this ostracode shell has an “extremely nodose and spiny carapace.”  (p. 117)

Nodose challenged my vocabulary, but it’s a great word.  According to the New Oxford American Dictionary, it's an adjective meaning “having or characterized by hard or tight lumps; knotty.”  The neat noun form is nodosity.  Savor that word.  Makes sense that nodule has the same Latin root.

Here are the drawings of C. exanthemata that Ulrich and Bassler included among the plates in the second volume of the work on the Maryland Miocene.

 They acknowledged some concern about precisely where C. exanthemata should come to rest taxonomically, but noted they were at work on a monograph which, “it is hoped, may result in a more natural and serviceable classification of the fossil species than the one now in use.”  I don’t think they ever followed through on this.  The taxonomic history of A. exanthemata prepared by Forester in 1980 includes no subsequent publication of theirs.

Now, of the 1904 duo who tackled the Maryland Miocene ostracodes, Ulrich had the reputation of being a splitter – seeing different species where others didn’t.  I’m not certain about Bassler in this regard.  (The career paths of the two men intrigue me and will be the subject of a future post.)

As a post-doctoral fellow at the U.S. Geological Survey, Forester reanalyzed the taxonomic decisions regarding these ostracodes made by Ulrich and Bassler in 1904 and several D.S. Malkin had made in a 1953 article (Biostratigraphic Study of Miocene Ostracoda of New Jersey, Maryland, and Virginia, Journal of Paleontology).  Forester concluded that Ulrich and Bassler were guilty of both splitting and lumping.  In some instances, they identified males, females, and juveniles of the same species as distinct species.  In others, the array of specimens they offered as examples of a single species should have been considered different species under current practice.  So, he redid the species.

Unfortunately, even after Forester’s work, the identification of A. exanthemata is, in my eyes, still rather obscure.  In his treatment of A. exanthemata, Forester drew a fine distinction among specimens that previous researchers had considered of the same species.  He concluded that figure 4 in the Ulrich and Bassler’s drawings of C. exanthemata (see above) was actually A. marylandica.  (Ulrich and Bassler noted that figure 4 was a drawing of the largest specimen of the purported species that they'd found.)  Forester acknowledged that “Actinocythereis exanthemata is most frequently confused with the lower Miocene to Holocene species A. marylandica (Howe and Hough, 1935),” and identified similar instances of this confusion by other researchers in the decades since 1904.  But, he asserted, A. marylandica is “larger and more robust” and has a “slightly different” spine arrangement.

That’s not much help for me, actually.  The size distinction isn’t useful without more specimens to work with and, it’s not really certain that any differences in the configuration of the spines are evidence of much.  In a later study of South Carolina ostracodes, Thomas M. Cronin commented that “[t]he degree of variability in the spines precludes separation [of these two species] on the basis of this characteristic.”  (Evolution of Neogene and Quaternary marine Ostracode, United States Atlantic Coastal Plain:  Evolution and speciation in Ostracoda, IV, appearing in Studies Related to the Charleston, South Carolina Earthquake of 1886 – Neogene and Quaternary Lithostratigraphy and Biostratigraphy, U.S. Geological Survey Professional Paper 1367, 1990, p. c-35.)

[Later edit:  I dropped a paragraph from the original post which suggested that the two species may actually be males and females of the same species.  I believe I misread a study by Frederick M. Swain (Some Upper Miocene and Pliocene(?) Ostracoda of Atlantic Coaster Region for Use in Hydrogeologic Studies, U.S. Geological Survey Professional Paper 821, 1974, p. 30.).]

Nevertheless, as far as I can unpack Forester’s description of A. exanthemata, I think my two specimens fit.  And, in this instance, I’m going to follow the National Football League approach (instant replay overrides the ruling on the field only in the face of indisputable evidence) and stay with A. exanthemata.

Of course, I also have a nonscientific motivation, I love that species name – exanthemata.  Its Greek root, exanthema, means “an eruption.”

[Much later and decidedly sheepish edit:  I'm really beginning to think that these two ostracode specimens may be from Henryhowella evax, not Actinocythereis at all.  H. evax is apparently more ovate than A. exanthemata.  Further, the spines on A. exanthemata appear more pronounced than those on the specimens above.  If this rethinking of mine is correct, it leaves me looking more than a bit foolish for having rambled on at length in this post about a couple of misidentified fossil ostracode shells.  My apologies.]
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