28 July 2016

The Paleo Travel List

Update (7/28/16) : Four years ago, I wrote this post in which I listed the paleontological sites and museums that I thought would make worthwhile trips for anyone with an interest in fossils.  Looking back at it now, I realized that I had a few additions (the University of Florida's museum and three German sites associated with the Messel lagerstätte) to make to it and that, as it might be a useful resource for people looking to plan paleo-centric travel, I should provide a permanent link to it on my main page.  I've made both changes and will try to update the list more frequently than I have been in the future.

Original Post (7/15/12): As many of you are aware, while paleontology is the main focus of this blog, I occasionally lapse into writing about places I've visited. I love to travel and I love reading travel literature, and I've noticed, as I'm sure many of you have, a recent trend in the field. If you go to the travel section of pretty much any bookstore, you'll see the usual guidebooks and travel narratives, but you'll also see books that are effectively lists of places to visit. Their titles are usually variations on the themes of "X Places to See Before you Die" and "X Places You Must Visit." I'm not altogether sure it's a healthy direction: I think travel should be about experiencing a culture or landscape different from the one you live in, not crossing items off a list (though, in fairness, "checklist travel" has a certain appeal to the more OCD aspects of my personality). Still, the popularity of these books - and the corresponding websites - is undeniable, and it got me wondering: what would a list of must-see paleontology destinations look like? My attempt at an answer can be found below.

A few places on the list were no-brainers: the big museums of the East Coast and Midwest, the grand collections of Europe, or places like Dinosaur National Monument and Petrified Forest National Park where you can see spectacular fossils in situ. I added a few other places because they do an outstanding job displaying the paleontology of a particular site (Rancho La Brea, Urweltmuseum Hauff) or region (University of Nebraska Museum, Staatliches Museum für Naturkunde). A few places made it onto the list because of their especially impressive combinations of fossils and reconstructions or paleoart (the dioramas of the Denver Museum of Nature & Science or the murals of the San Diego Natural History Museum, for example), and a few more made it on due to the historical importance of the fossils there (the first described dinosaur fossil in Oxford's Natural History Museum, for example).

Obviously, this list is incomplete. It includes only places I've visited, leaving entire continents neglected. I'd be very curious to hear what else readers of this blog think would belong on it. Bear in mind that this list is intended for members of the general public, NOT for career paleontologists; we all have our own distinct ideas of which museums or sites are particularly interesting, and many of these may hold little to no appeal for someone with a more casual interest in fossils. However, I think any of the places listed below would be worth a trip for anyone with even a slight predilection for paleontology:

Map of Sites

United States


Canada

Royal Tyrell Museum, Drumheller, Alberta

Canadian Museum of Nature, Ottawa, Ontario


Germany

Humboldt Museum für Naturkunde, Berlin

Grube Messel (reviewed 12/2015)/Hessisches Landesmuseum Darmstadt/Naturmuseum Senckenberg, Messel/Darmstadt/Frankfurt, Hesse

Paläontologische Sammlung, Tübingen, Baden-Württemberg

Staatliches Museum für Naturkunde, Stuttgart, Baden-Württemberg

Urweltmuseum Hauff, Holzmaden, Baden-Württemberg


United Kingdom

08 July 2016

Fossil Vertebrate of the Month: Miracinonyx

Natural Trap Cave
Photo by the author
This year being the centennial of the US National Park Service, the ecosystems and animals of Yellowstone have been on lots of peoples' minds (and itineraries).  Certainly, the Greater Yellowstone Ecosystem remains the best place in the continental United States to see what remains of North America's megafauna, but a site roughly a hundred miles to the east attests to how much more diverse that fauna used to be.  On the hills above Bighorn Canyon on the Wyoming-Montana border sits Natural Trap Cave, one of the most important Pleistocene vertebrate localities in the world.  Then as now, the cave is a huge hole in the ground, and while a grate keeps anything too big from falling in anymore, during the Pleistocene it was a death trap for tens of thousands of animals.  I was fortunate enough to be able to spend some time working at the site this month, and while my contributions consisted mainly of rodent bones and teeth, the cave has yielded fossils of a wide range of animals.  Some of these - bison, wolves, wolverines, to name a few - would be familiar to Yellowstone visitors today.  Some - mammoths, horses, and camels, for example - are now extinct but are nevertheless fairly familiar.  Others are more obscure, and perhaps the weirdest of these often overlooked animals is the American cheetah Miracinonyx.  Really, I should have quotes around the word "cheetah," as the evolutionary history of Miracinonyx has long been a bone of contention.  It was first described on the basis of fossils from Pennsylvania by the great paleontologist E.D. Cope in the 1890s, who placed it in Uncia, the same genus as modern snow leopards.  Other finds from the east led 20th Century researchers to conclude that it was closely related to modern Puma, the genus that includes modern jaguarundis and cougars.  It was specimens from Natural Trap Cave described in the 1970s that first demonstrated that Miracinonyx had extremely elongated legs similar to those of cheetahs, indicating that it too hunted its prey by chasing it down.  This was something of a bombshell, as most cats are ambush predators specialized for sneaking up on prey and pouncing; modern cheetahs are the only modern big cat that is a really effective pursuit predator.  It was widely suggested that this similarity in morphology meant that North American and African cheetahs not only hunted in a comparable and unusual way, but that they were very closely related.  Consequently, during the 1980s most authors referred Miracinonyx specimens to the Acinonyx, the genus of modern cheetahs.  All this taxonomy may seem very dry and dull, but it has an important implication: that despite their geographic distance, cheetahs in North America and Africa were similar because they were close relatives descended from a recent common ancestor, an evolutionary phenomenon known as parallelism.  However, since 1990 our understanding of the evolutionary history of Miracinonyx has changed substantially.  That was the year that Blaire Van Valkenburgh and colleagues performed an analysis of the morphology of a specimen from a West Virginia cave and showed that, in fact, the animal that paleontologists had been referring to for years as a cheetah was actually a very close relative of cougars.  This finding was later backed up by an analysis of ancient felid DNA, which likewise showed a close relationship between Miracinonyx and Puma.  The North American cheetah's evolution switched from being an example of parallelism to one of convergence, in which two unrelated species evolve similar traits due to similar environmental pressures.  It has been further argued, though with considerably less direct evidence, that the evolution of pursuit predation in Miracinonyx may have had a major impact that can still be observed today.  As "cheetahs" got faster, it would likely have put pressure on their prey to evolve traits that would allow them to run faster as well, which would in turn lead to further pressure towards speed-related traits in Miracinonyx in a process known as coevolution (or, more colorfully, an evolutionary arms race).  This could explain the blazing speed of the still-extant pronghorn Antilocapra, which has been clocked at over 60 miles per hour.  This is far faster than any living mammalian predator in North America, but well below the top speed of modern cheetahs.  So if you do make it to one of the western national parks this centennial year and you're fortunate enough to see a herd of pronghorn running at full tilt, spare a thought for the bizarre cat that may have made such velocity necessary.
Miracinonyx and Antilocapra
Reconstruction by Mauricio Antón

14 June 2016

In Memoriam: Robert T. Paine

Remove a particularly important species from an ecosystem and the catastrophic consequences can ensue.  This, in painfully abbreviated form, is the summary of what must be considered the most significant study of the illustrious career of the great ecologist Robert T. Paine, who died this week.  The notion that removing a critical species - a keystone species, to use the term Bob coined - can lead to a crash in diversity may seem obvious enough today, but it was anything but in 1969.  This was the year in which Bob published his research on the effects of predation by the sea star Pisaster on the intertidal communities on the lands of the Makah Nation on the far northwest tip of the Olympic Peninsula.  One might expect that the removal of the ecosystem's top predator would cause its prey to become common across the board, but instead the removal of sea stars released mussels from their main form of population control, allowing them to take over swathes of the intertidal and driving out almost all - indeed, in some cases, all - other animal species.  Because of the importance of Pisaster in controlling diversity on the rocky shores of the Northwest, it was likened to a keystone in an arch which, if removed, will cause the entire structure to collapse.  The concept of keystone predators has since grown to become one of the most important in all of ecology, informing studies in areas as diverse as conservation biology and my own field of paleoecology.  It is also unquestionably the largest academic feather in Bob's cap (which is so covered in feathers that it resembles the head of one of the coastal birds whose calls he could so precisely identify and interpret), but I would argue that the idea of keystone species was not Bob's greatest contribution overall.  Somewhat ironically, a man best known for analyses of what happens when when an important player is removed from a community had his most profound impact by adding to the ranks of the scientific community.  By mentoring generations of students and postdocs, who themselves would go on to mentor others, he was the father of what has quite reasonably been described as a dynasty of ecologists, the impressive scope of which is best appreciated in visual form.  It was in 2003 in the capacity of a summer research assistant for two of Bob's former students, Cathy Pfister and Tim Wootton, that I met Bob, who accompanied us on several trips to Tatoosh Island, one of the world's great natural laboratories.  I doubt he would have remembered me (and, given that I was fairly new to ecology at that point and exceedingly new to serious field work, this is probably for the best), but to have been even a bit player in the saga of one of the century's great biologists has been one of the great honors of my life thus far.  Even my relatively brief interaction with him, with his students, and with his students' students, was enough to impress upon me the significance of his legacy.  Cooperating with the Makah, he established a study area on Tatoosh and on nearby areas of the mainland that has been the focus of active research since the '60s, and for anyone interested in the long-term effects of changes in climate and other ecological variables, the importance of such an extensive data set cannot be overstated.  One of my most enduring memories of Bob was a discussion we had after dinner one evening, in which he talked about his pride not only having established the research program on Tatoosh but in knowing that he had inspired others to ask similar questions to those he had been asking, meaning that this program would perpetuate itself well into the future.  Perhaps this moment of self-reflection stands out to me because of Bob's generally (though good-naturedly) cantankerous demeanor (another enduring memory I have of that summer is him knocking down swallow nests in our sleeping area before a visiting scientist arrived, since he was concerned they had "a mystical view of nature" but was under no circumstances going to sleep beneath what amounted to a guano factory), but it also stands out because it was so clearly true.  In a field that is often accused of relying heavily on models and on extrapolations beyond available data, Bob understood better than anyone the value of data gathered in the field for answering some of the most important scientific questions of our age.  This understanding is what made him a titanic figure in ecology, and his ability to impart this understanding and his enthusiasm for field-based experimental research is what truly cemented this status.  His prowess as a researcher means his death will leave a huge hole in the world of ecology, but the legion of ecologists he inspired will insure that the community of which he was a part will continue to thrive.

22 May 2016

Conference Review: Rocky Mountain GSA

The University of Idaho
Site of this year's Rocky Mountain GSA meeting
This week, the Rocky Mountain Section of the Geological Society of America descended from said mountains to the Inland Northwest, hosting their annual meeting in at the University of Idaho in Moscow.  While I hadn't submitted an abstract, the combination of proximity, a freer schedule now that classes are over for the year, a field trip to Clarkia, and a session on lagerstätten was enough to entice me down to the Palouse.  While paleontology did not feature nearly as prominently as it did at the previous GSA sectional meeting I'd attended, there were a few highlights that I wanted to share:


  • The primary allure of the conference was the field trip to the Clarkia fossil beds of north-central Idaho.  Having taken my Paleobiology class to one of these sites last semester, I had some familiarity with the Clarkia fossils, but I didn't want to pass up a chance to learn more about them from researchers who had focused on them, notably co-organizers palynologist Bridget Wade  and paleobotanist Bill Rember, both of UI, and Ralph Stearley of Calvin College, who has worked on fossil fish from around the Northwest.  The organizers, my fellow attendees, and the fossils themselves predictably did not disappoint.  My effusive praise of Clarkia deserves a post of its own, so expect one in the near future.  For now, all I'll say is that it ranks right up there with sites such as Ashfall and Messel in terms of the paleobiological story it tells, and it surpasses all other sites I know of in terms of quality of preservation.
  • Speaking of Clarkia, there was one presentation relevant to it at the conference, but it focused not on fossils but on several layers of volcanic ash present at various localities in the region.  The research, conducted by Washington State's Cassie Geraghty, found that several of the ash layers were likely produced by a volcanic field in northern Nevada that was active about 15.5 million years ago.  This is significant because it means that the Clarkia biota lived at the peak of the Mid-Miocene Climatic Optimum, the last major period of global warming in Earth's history, making it not only intrinsically interesting from an ecological perspective, but providing a possible glimpse of what might happen to organisms and ecosystems as climate continues to warm going into the future.  Another poster in the same session, by Klarissa Davis, also of WSU, looked into the connection between volcanism and climate in the mid-Miocene, suggesting that the Columbia River Basalts, that still cover much of the Inland Northwest today, may have played a large role in driving climate at the time by releasing greenhouse gases during eruption.
  • The only paleontology-focused session was on lagerstätten, and featured several talks by
    The sunfish Archoplites
    Clarkia Fossil Beds
    paleontologists from around (and, in a few cases, beyond) the region.  The most interesting from my perspective was given by the University of Montana's Lindsey Mackenzie.  There has been a long-standing tradition of categorizing lagerstätten into "preservation type" groups (e.g, Burgess Shale-type preservation).  Lindsay's work recently has been on analyzing whether or not these groups actually reflect chemical, geological, and geographic reality.  The project is still in its infancy, but it should be very interesting to see how it unfolds, as it will probably have major paleoecological implications.  Other interesting talks in the session included descriptions of the invertebrate faunas of the Raven's Throat and Bear Gulch lagerstätten by Julien Kimmig and Amy Singer, respectively, and of the Miocene fossil fish of Idaho and Oregon by the aforementioned Ralph Stearley.  The most exciting bit of news from the latter talk was that Ralph and his colleagues may have identified a kokanee population of the saber-toothed salmon Oncorhynchus rastrosus; that is, they have evidence that a landlocked population of the usually enormous fish became dwarfed, which would certainly add a new twist to the saga of one of the Northwest's most bizarre extinct animals.

19 March 2016

Fossil Vertebrate(s) of the Month: Glyptodontinae

Glyptodon clavipes & other South American megafauna
Field Museum
It's an old adage that one of the joys of paleontology is that you never know what you're going to find in the field.  It could be something fantastically bizarre or gorgeous, or it could be something that changes our understanding of a group's evolution.  As paleontology itself evolves into a more analytical field, new and improved research methods lead mean that game-changing discoveries now happen in the lab at least as frequently as they do in the field.  A prime example of this is a subfamily of South American mammals known as the glyptodontines.  Were I writing this a month ago, I'd have referred to them as glyptodontids, members of their own distinct family related to, but distinct from, sloths, anteaters, and armadillos.  Glyptodonts are as far from a recently-discovered taxon as you can get, having been named in 1879 and even before that having been the subject of study by such luminaries as Darwin and Owen.  Likewise, they are anything but obscure, having long been the focus of both scientific and public attention, due in no small part to their size (the largest are often compared to VW Beetles), their massive shells composed of hexagonal plates (the size and bulkiness of which leading to relatively high rates of preservation and a very good fossil record), and their armored (and in some cases weaponized) tails.  And yet, there's still a lot we don't know about even such a seemingly well-understood group.  Until now, I've used glyptodonts as prime examples of convergence, evolving armor similar to that of armadillos despite being from a separate xenarthran lineage.  Last month, though, a study by Frederic Delsuc and colleagues showed that armadillos and glyptodonts are similar not due to convergence, but because they are very closely related.  In fact, using mitochondrial DNA recovered from a 12,000 year old specimen of the spike-tailed glyptodont Doedicurus, Delsuc et al. showed that not only do glyptodonts belong to the same order (Cingulata) as armadillos, they can actually be placed in the armadillo family Chlamyphoridae.  This family does not include armadillos of the genus Dasypus so familiar to Texans and Floridians, but it does include, among other species, the pink fairy armadillo and the giant armadillo (competitor and, sadly, early-round upset victim in March Mammal Madness).  That such a well-studied group can still surprise us as we develop new methods of study is not only a testament to the data-driven, non-dogmatic nature of science, but nicely illustrates why it's so much fun to study fossils: be it on the pampas of Argentina or in a genetics lab in Montpellier, you really never know what you're going to find.

25 December 2015

Fossils 'Neath the Tree

video
Of course, one of the joys of any advent calendar is the payoff at the end, so here's my gift to you: lots and lots of lagerstätten set to Tchaikovsky.  Note that I only used my photos, so not every site I highlighted is included and there's a strong emphasis on Neogene mammals.  Happy Holidays!

24 December 2015

24. Frozen Mummies of the Far North

Frozen Siberian Cave Lions Cubs
National Geographic
Location: Siberia, Russia & Alaska, USA
Age: Pleistocene

Over the last 24 days, we've seen lagerstätten preserved in many different ways, all of which have in some way helped tell the story of how climate change through the Cenozoic has affected life on land.  Today, to close out the advent calendar, we're ending with specimens that share not a particular locality but rather a particular environment of preservation, one that only exists because of the cold climate of the Pleistocene.  Original soft tissue - muscles, organs, skin, and hair - are not unheard of from the Pleistocene.  Mummies have been preserved in dry caves across the globe: moas in New Zealand, thylacines in Australia, ground sloths in Patagonia and the Mojave Desert.  Even more spectacular are those animals that have been frozen in the permafrost of the far reaches of the Northern Hemisphere.  Permafrost is the frozen soil that underlies the tundra of Siberia and Alaska and, if any organism is buried in either region's sediments before being significantly scavenged or decomposed, it can become preserved in the subsurface ice.  Melting during warmer periods or, more recently, mining brings these remains to light with surprising frequency.  Because they consist of original organic material, these permafrost mummies do not qualify as fossils by everyone's definition.  For those of us that do consider them to be a part of the fossil record, though, the Siberian and Alaskan permafrost constitute what has been referred to as "the ultimate lagerstätte." Frozen woolly rhinos have been unearthed, as have bison (see the University of Alaska's "Blue Babe" for a particularly well-known example), horses, and numerous other animals.  Very recently, a discovery of frozen Siberian cave lion cubs made major waves, but historically (and as with many sites profiled in the last week) the real stars of the show are mammoths.  In fact, a frozen woolly mammoth brought back to St. Petersburg at the end of the 18th Century was one of the first fossils of any type of organism to pique the interest of the general public.  Today, permafrost mummies are sources of hugely valuable information about life in the subarctic regions of the world during the Pleistocene (they have also, unfortunately, become lightning rods for creationists, who have frequently made the claim that the specimens show evidence for rapid freezing, allegedly falsifying gradualist explanations for the history of Earth and its life - I need hardly remark that such evidence is, in fact, nonexistent).  Organisms and ecosystems from the polar regions of the world are the first to feel the effects of climatic change, so the light that permafrost mummies can shed on how life has responded to periods of warming and cooling in the past could be invaluable for illuminating the future of modern subarctic organisms.

Visit: Permafrost is widespread (though increasingly rare) beneath the tundras of Alaska, Canada, and Russia.  However, as a subsurface feature, it's not something easily observed.  The best opportunity I know of for doing so is the Permafrost Tunnel Research Facility near Fairbanks.  As a research site, it's not generally open to the public, but the Army Corps of Engineers does lead occasional tours.
Fossils: In the continental US, your best bet is the American Museum of Natural History, home to both a frozen mammoth and a frozen squirrel, nicely demonstrating that it's not just megafauna that were frozen.  The University of Alaska Museum of the North has an especially important collection, including the aforementioned "Blue Babe."  My lack of Russian language skills makes verification of this difficult, but the two museums that have historically housed permafrost mummies in that country are St. Petersburg's Zoological Museum and Moscow's Paleontological Museum.
Is there a relevant book full of gorgeous fossil photos that I can gift to a paleontologically-minded friend?: Several!  Enough, in fact, that I'll simply leave it to you all to search for one that suits your interests rather than linking to any in particular.

This post is part of my 2015 Paleontology Advent Calendar, a series of vignettes on lagerstätten - sites of exceptional fossil preservation - that document changes in climate and environments through the Cenozoic.  You can see the other posts here.