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Paleontological field work and nuclear testing

In the mid to late 1950s, Charles L. Camp, Professor in the Department of Paleontology and former Director of UCMP (1930-1949), spent his summers working at what would later become Berlin-Ichthyosaur State Park, about 55 miles north of Tonopah, Nevada, and 150 miles northwest of Yucca Flat at the Nevada Test Site.

Beginning in 1951 and ending in 1992, the United States did extensive nuclear testing at Yucca Flat. There were 739 tests conducted there, resulting in Yucca Flat being called “the most irradiated, nuclear-blasted spot on the face of the earth.”1 Large amounts of radioactive material were released into the atmosphere, and communities downwind of the test site, such as St. George, Utah, felt the effects of this. See this Journal of the American Medical Association article.

The government publicized the dates and times of scheduled tests so Camp was aware that they were going on while he worked at the ichthyosaur site. In his field notes from 1955 to 1957, he mentions three of these tests:

Apple-2 test

The Apple-2 atomic test conducted on May 5, 1955.


On May 6, 1955, Camp wrote “The atom went off yesterday morning and I didn’t hear or see it. Harold [Harold Newman, a local who assisted Camp] claims he did.”

This was “Apple-2,” the 13th atomic test in a series of 14 called Operation Teapot conducted at the Nevada Test Site. It’s yield was 29 kilotons.

A few days later, on May 15, Camp could not help noticing the atomic blast: “The 14th big atom went off this morning at 5 [5:00 am], 200 miles away. I sat up in bed and saw a violet-pink flash lasting a fraction of a second. About 15 min. later a low grumbling thunderous roar came in like thunder shaking the earth a little. This came in two or three crescendos. About 3-5 min. later a more subdued noise like far away growling of lions came through the air without quite so much force.”

This was “Zucchini,” the final test of Operation Teapot, with a yield of 28 kilotons. According to a 1997 National Cancer Institute report, civilian exposure to some 24,500 kilocuries of radioiodine that had been released into the atmosphere by the Teapot tests would eventually cause about 13,000 cases of thyroid cancer.

On July 5, 1957, Camp experienced another blast: “Big bomb from balloon went off at 5 am and rattled the windows, shook the cabin and growled like thunder. Flash very bright 20 seconds before blasts hit. Three blasts (one ‘aftershock’ I suppose).”

Hood test

The 74-kiloton Hood atomic test conducted on July 5, 1957.


This was the 74-kiloton “Hood” test, fourth in a series of 29 tests called Operation Plumbbob that were conducted from May through October of 1957. It was the largest atmospheric test ever conducted within the continental United States and it was almost five times as powerful as the atomic bomb dropped on Hiroshima (15 kilotons). The device was carried aloft by a balloon and detonated at 460 meters above the ground. According to the same National Cancer Institute report mentioned above, the Plumbbob test series put more than twice as much radioiodine into the atmosphere as any other series, and about 38,000 eventual cases of thyroid cancer were expected to be the outcome.

Despite his proximity to the test site, Charles Camp lived to be 82, dying in 1975, albeit from cancer. The prevailing westerly winds that blew the radiation clouds towards Utah were probably his saving grace.

 

1Clarfield, G.H., and W.M. Wiecek. 1984. Nuclear America: Military and Civilian Nuclear Power in the United States 1940–1980. Harper & Row, New York. P. 202.

Photos are from http://nuclearweaponarchive.org; the images are believed to be in the public domain.

New fossil footprint exhibit debuts online

Fossil tracks logoVisit the new UCMP/University of Colorado online exhibit on fossil tracks! It is fascinating to consider that fossil footprints and trackways offer direct physical evidence that ancient animals passed through an area long ago. However, these trace fossils also provide important clues that shed light on several aspects of paleobiology, such as anatomy, locomotion patterns, behavior, and footprint preservation. The website provides basic information about the preservation of fossil tracks, how they are studied, and where they have been found. You can also test your fossil track expertise in the “Who made these fossil tracks?” section.

University of Colorado graduate student, Allison Vitkus is lead author on the exhibit, which was produced with funding from a National Science Foundation grant to Karen Chin and Martin Lockley. Martin Lockley spent his career at the University of Colorado Denver amassing one of the world’s most diverse collections of fossil tracks. This extensively-studied collection was held at the University of Colorado Dinosaur Tracks Museum in Denver but has now been moved to the University of Colorado Museum of Natural History in Boulder. NSF provided funds to transfer the specimens, make curatorial improvements to the collection, develop a searchable online catalog of the collection, and share information about this exciting collection with the public in this new UCMP online exhibit!

Global change consensus statement having a global impact

Page from consensus statementOver a year ago in a May 30, 2013, blog post, we reported on Professor of Integrative Biology and UCMP curator Tony Barnosky’s presentation to Governor Jerry Brown of a statement about global environmental problems and what people must do to ensure the health of the planet. That statement was written at Brown’s request after the Governor had heard about a Nature paper that Barnosky had coauthored with his wife, Stanford professor of Biology and UCMP research associate Elizabeth Hadly, and several other scientists in June 2012 (Nature 486:52-58). Brown wanted to use the statement as a powerful tool with which to help him shape environmental policy, and it has done that. Furthermore, the statement which has now been endorsed by over 3,300 people (mostly researchers) around the world, has influenced environmental policy well beyond California’s borders. Read the complete statement on the ConsensusForAction website.

Governor Brown presented copies of the statement to President Obama and Chinese President Xi Jinping. Since then, California and China have agreed to jointly develop green technologies and to reduce greenhouse gases. California, Oregon, Washington, and British Columbia have signed a pact to use ideas set forth in the statement as the basis for making energy and environmental decisions. The statement has been translated into several other languages and has found its way into the hands of politicians around the globe. Members of Nepal’s parliament have signed the statement and intend to address climate change when writing a draft for their new constitution. As Hadly put it, “We never could have guessed the reach this paper has had.”

In the July 24, 2014, issue of Nature (Nature 511:402-404), a news feature praises the work of “information advocates” Barnosky and Hadly.

Making the Earth sciences engaging and relevant for broader communities

Lisa at Cal Day

Lisa White at Cal Day, April 2014. Photo courtesy of Pat Holroyd.

Historically, paleontology has been a male-dominated field. Over the past few decades, more and more women have entered the field, but female African-American paleontologists remain a rarity. Lisa White, UCMP’s Assistant Director of Education and Public Programs, is one of these rare women. She spent 22 years as a faculty member at San Francisco State University and held the titles of Professor and Associate Dean when she came to Berkeley in 2012. White was profiled recently in California, UC Berkeley’s alumni magazine.

White has been involved in a variety of programs that introduce minority youth to the Earth sciences, providing them with hands-on experiences both in the lab and in the field to help make the subject engaging and relevant. Two of these programs are “Reaching Out to Communities and Kids with Science in San Francisco” (SF-ROCKS) and “Minority Education Through Traveling and Learning in the Sciences” (METALS).

White gets excited by science and she shares that enthusiasm, both with minorities and the general public as a whole. “We’re trying to reach entire communities that may never be able to access the collections at the museum [UCMP’s collections are closed to the public], but I think they can get excited about what those collections tell us about life in the past.”

Flash! Grad student discovers how Ctenoides ales, the “disco clam,” flashes

Back in 2010, while diving in Indonesia, Lindsey Dougherty first witnessed the flashing behavior of the so-called “electric clam” or “disco clam,” Ctenoides ales. She decided then and there that the focus of her Ph.D. would be the study of these fascinating bivalve mollusks.

Disco clam flashing

Ctenoides ales caught in the act of flashing. In the photo, it's the silvery white band along the lip of the mantle. Photo by Lindsey Dougherty.

Now, four years later, Dougherty reports in the British Journal of the Royal Society Interface just how the flashing works. A nice description of the mechanism and a video showing the flashing behavior is provided in Robert Sanders’ article on UC Berkeley’s News Center website. Also see The Royal Society’s news blurb (with more video footage) about the study, listen to Lindsey describe her research in a New York Times Science Times podcast on iTunes, or check out this ABC News video that aired on July 23.

Lindsey on Cal Day

Lindsey Dougherty describes her work with Ctenoides ales to a Cal Day audience. Cal Day is the annual campus-wide open house that takes place every April. Photo by Jenny Hofmeister.

Dougherty is now looking into the reasons for the flashing behavior. Perhaps it attracts prey or serves as a warning to potential predators; or maybe it’s a signal to juveniles of its own species that this is a good substrate on which to settle. We’ll have to wait and see what Dougherty finds out!

Here are some of the other news outlets and organizations that picked up the disco clam story:

75-year-old sculptures by William Gordon Huff relocated

For the past three years or so I have been researching the life of sculptor William Gordon Huff. Never heard of him? That’s not too surprising since he didn’t have gallery shows and, to my knowledge, no major museum has examples of his work. But, if you do any traveling in California, there’s a good chance that you’ve seen Huff’s work without even knowing it, because most of his sculpture was public art, primarily in the form of bronze bas reliefs for historical plaques. Huff’s plaques can be found in Hangtown, Camptonville, Columbia, Ukiah, Peña Adobe Park, Angels Camp, Murphys, Napa, Monterey, Stockton, Pt. Reyes, Benicia, Alameda, and the University of California’s Angelo Reserve, to name a few places. And then there are his ceramic plaques on The Wall of Comparative Ovations in the Sierra foothills town of Murphys, but that’s a whole story in itself.

Huff’s most notable works, and those that garnered the most media attention, were created back in the 1930s, beginning with his 12-foot bronze statue of Chief Solano. This piece, dating from 1934, can still be seen in Fairfield in front of the Solano County offices at the corner of West Texas Street and Union Avenue.

But Huff is probably best known for his work on the 1939-1940 Golden Gate International Exposition (GGIE) that was held on Treasure Island. He constructed four, 20-foot-tall, free-standing figures — two of each — representing "The Arts," "Industry," "Science," and "Agriculture" to fill eight archways in the octagonal Tower of the Sun, the central feature at the fair. He made 28 nine-foot-tall, free-standing female figures for buttresses surrounding the Court of Flowers, as well as two figures for the east side of the Arch of Triumph, which connected the Court of Flowers to the Court of Reflections.

Nimitz plaque, Chief Solano, The Arts

Top: Huff with a fine plaque that he made for the Alameda Naval Air Station. This plaque was unveiled in January, 1967, at the dedication of the station’s airfield as Nimitz Field. Photo from the Huff archives. Below left: Huff with his statue of Chief Solano in 1934. Below right: Huff working on one of his figures for the GGIE’s Tower of the Sun. This and the Chief Solano photo are courtesy of Kevin Phipps, Huff’s grandson.

At the same time as he was working on these monumental sculptures, he was preparing GGIE exhibits for the Department of Paleontology. With painter Ray Strong doing the backgrounds, Huff sculpted the animals and foregrounds for six 1/6th-scale dioramas, depicting scenes from different geologic time periods. Huff also made five life-size heads of Miocene and Pleistocene mammals as well as a 13-by-7-foot bas relief of two American Lions (Felis atrox) attacking a giant Ice Age bison (Bison latifrons). Huff helped with three or four smaller exhibits in addition to these but no sculptures were needed for them.

Permian and Pleistocene dioramas

Top: A portion of the Permian period diorama as it appeared in 1939. Bottom: The Pleistocene epoch diorama as it appeared in 1939. Both photos are from the UCMP archives.

The GGIE was intended to last only a single year, but because it didn’t make enough money, it ran for a second year. Huff made some new sculptural additions to the paleontology exhibit for 1940. He made 20 small plaques of prehistoric animals, a display of invertebrate fossils from Mt. Diablo, and perhaps more.

Since the GGIE exhibits were meant to be temporary, all of Huff’s sculptures were made of plaster. When I began my investigations into the life of William Gordon Huff, only two of his GGIE sculptures were known to still exist: (1) the large bas relief of the lions attacking the bison — this piece is in UCMP’s storage facility in Richmond — and (2) one of the five life-size heads, that of Synthetoceras (a Miocene deer-like mammal) that was restored and featured in UCMP’s Cal Day display two years ago. Nobody knew what had become of the six dioramas or the other four life-size heads; I assumed that they had fallen apart or had been destroyed. Who expected these temporary plaster sculptures to survive 75 years?

But in the span of one month, I have seen two of the six dioramas and two of the original five life-size heads — plus a completely unknown sixth head!

The dioramas
It took a while to track down the dioramas. Documents in the UCMP archives indicated that the six were brought back to Berkeley following the GGIE and were installed in Bacon Hall; they remained there through at least 1947. According to another archival document, the dioramas were transferred to the California Academy of Sciences in San Francisco at some point. Two of the dioramas were acquired by San Francisco’s Randall Museum; when that was is unknown and what became of the other four is still a mystery. But in the early 1980s, the Randall Museum gave their two dioramas back to UCMP. They were kept at the museum’s Clark-Kerr storage facility until around 1997 when Diane Blades, representing the San Joaquin Valley Paleontology Foundation, took them south, ostensibly for the Fossil Discovery Center in Chowchilla. But they did not end up there. It’s not clear where the dioramas were between 1997 and 2012, the year they were discovered in a Madera Library storage space. Lori Pond, president of the San Joaquin Valley Paleontology Foundation, rescued the dioramas just days before they were scheduled to be broken up and hauled off to the landfill. Today, the two dioramas, representing the Permian and Pleistocene, are sitting in Lori’s garage. She hopes to find funding to have the dioramas cleaned and restored, but more importantly, she’d like to find them a new home; a place where the public can view them as it once did 75 years ago on Treasure Island.

Permian and Pleistocene dioramas today

Top: Mark Humpal, Portland art galley owner and art historian, admires the Permian diorama. Note the collapsed fragments of a Dimetrodon sculpture at the center of the photo. Bottom: The Pleistocene diorama as it appeared in May 2014. Note that part of the mammoth’s tusk has fallen and that one Smilodon has broken off its supporting armature. Both photos by Dave Smith.

The life-size heads
The discovery of two of the original GGIE life-size heads and of a third new one (perhaps a 1940 addition to the GGIE paleontology exhibit) was serendipitous. In 2012, Senior Museum Scientist Pat Holroyd was talking with Sally Shelton, Associate Director of the Museum of Geology and Paleontology Research Laboratory, South Dakota School of Mines and Technology, about collections issues when Pat happened to mention Huff’s name. Sally revealed that in moving to a new building, their museum discovered three sculpted heads by Huff for which they’d love to find a new home. Pat relayed this information to Associate Director for Collections and Research Mark Goodwin. Mark, who has a strong interest in UCMP’s history, said that he would gladly take the heads and pay for the shipping costs. It took a while, but this summer, a 450-pound crate containing the three heads arrived at the museum. The two heads that were made for the 1939 GGIE are (1) Paramylodon, a giant ground sloth, based on a skull from the Pleistocene Rancho La Brea asphalt pits of southern California; and (2) Hipparion, a three-toed Miocene horse, from a skull found at the Black Hawk Ranch Quarry near Danville. The new head is of Pliohippus, a one-toed Miocene horse.

The heads in 1957 and in 2012

Top: The Smilodon, Hipparion, Paramylodon, and Synthetoceras heads in the Hearst Memorial Mining Building circa 1957. Photo from the UCMP archives. Bottom: The heads of Hipparion, Pliohippus, and Paramylodon in South Dakota, 2012. They appear to have been painted at some point. Photo by Sally Shelton.

How did the heads end up in South Dakota? Both Professor Emeritus Bill Clemens and Sally Shelton believe that Reid Macdonald may have been responsible. Reid got his Ph.D. at Berkeley in 1949 and took a job as curator at the Museum of Geology, South Dakota School of Mines and Technology, that same year. But he left that position in 1957 and in the UCMP archives, there is a photo, circa 1957, that shows the heads still in Berkeley. Reid retired to Rapid City in 1980 and lived out the last 24 years of his life there. It’s still possible that he was behind the transfer of the heads to South Dakota but as yet, there is no hard evidence.

Dave Smith with heads

Dave Smith with the three Huff heads after removing the sides of the shipping crate and removing all the paper packed around them. Photo by Mark Goodwin.

Nevertheless, now only the heads of Bison latifrons and Smilodon are unaccounted for. Since they are arguably the finest heads in the bunch, it’s entirely possible that they still exist somewhere. Perhaps someday, they too will return home to UCMP.

Where have all the mammoths gone? And why do we care?

What’s the first thing that comes to mind when you think of Africa? Probably a lot of big animals, right? Elephants and lions, zebras and cheetahs, hippos and rhinos, giraffes, and enormous herds of wildebeest moving across the savannah.

African animals

A selection of modern African animals, including megafauna. Image in the public domain.

Well, what a lot of people don’t realize is that for most of the past 50 million years, most of the world looked a lot like Africa! Not that long ago, Europe, Asia, and North and South America all hosted relatives of elephants, zebras, and lions inhabiting ecosystems that looked a lot like today's African savannah. There were rhinos roaming the Riviera, wooly mammoths wandering Wyoming, and Glyptodons (a kind of giant armadillo) gallivanting in Guyana. Here in California we had mammoths and mastodons (another elephant relative), horses and tapirs, oxen and antelopes, jaguars and lions, saber-toothed cats (our state fossil!), giant wolves, giant bears, giant bison, and (my favorite) giant sloths. South America had rodents the size of cows. Australia had wombats the size of hippos. Even relatively small islands had giant mammals, although not quite as giant as on the continents, because big animals tend to get smaller (and small animals bigger) on islands. There were giant lemurs on Madagascar, pygmy hippos in the Mediterranean, dwarf giant sloths in the Caribbean, and pygmy mammoths on California’s Channel Islands.

South American megafauna

South American megafauna 15,000 years ago during the Pleistocene. Photo jqjacobs.net.

Scientists call these giant animals “megafauna” (mega = big, and fauna = animals). We still have megafauna in the world, but there used to be a whole lot more of it. In fact, it appears that having a large number of large-bodied animals in an ecosystem is actually the normal state for our planet, at least for the geologic era we are living in today, the Cenozoic (or “Age of Mammals”) . But sometime in the past 50,000 years (very recent geologically), everywhere except for Africa, most of those large animals became extinct. And we still aren’t sure why!

People often ask me, “Why was everything bigger in the past?” But I think the question should really be the other way around — “Why is everything so small now?” As a paleontologist studying the extinction of the megafauna, this is a question I ask on a daily basis.

Basically, there are two main ideas about why these large animals went extinct. One hypothesis is that the extinctions were actually due to us — to humans. The scientists who peg people as the culprits point to several lines of evidence: For one thing, in most of the places where the extinctions happened, large animals tend to disappear from ecosystems right about the same time that humans arrive for the first time (we know this from radioisotopic dating, scientific techniques that allow us to determine the exact age of fossils and the sediments they are found in). Also, in a few places, we actually have evidence of humans hunting extinct megafauna, such as mammoths. Finally, we know from modern situations that humans can have a major impact on animals, both directly (like hunting) and indirectly (like burning forests, fragmenting habitats, and causing erosion) .

The second hypothesis for why the megafauna went extinct is that the climate changed too much (or too fast), and the animals could not adapt to their new environments. We know that climate was changing at the time that the megafauna disappeared in many parts of the world, and in some places (including Ireland and northern Europe and Asia) the extinctions seem to be correlated with changes in vegetation and stress that can be directly linked to climate. Scientists who favor this hypothesis also point out that given all the fossils we have of extinct megafauna, only a handful show any evidence of hunting by humans.

Finally, there are some scientists — including myself and many of my colleagues — who think that most of the global megafauna extinctions probably resulted from a combination of both climate and human impacts. While there appear to be some places where extinctions may have been caused by climate change alone, and others where humans were the sole culprit, it seems that more species went extinct faster in regions where both of these factors came into play simultaneously. Whatever the answer, scientists all over the world are working to learn more about why our world looks so different today than it did in the past.

Why do we care about what caused the megafauna extinctions? Aside from the “wow” factor of reimagining these past ecosystems, large mammals constitute many of the world’s most currently endangered species, and so understanding how these animals are affected by climate changes and human activities might help us prevent the megafauna that are still alive today from disappearing too. This is important not only because it would be sad to have a world with no elephants, tigers, or polar bears, but also because losing these big animals could spell trouble for a lot of other species, including humans. Megafauna have major impacts on Earth’s ecosystems: they affect what plants grow where, how often and long forest fires burn, and how rich the soil is. They are important transporters of nutrients and seeds, and they can create and destroy habitat for smaller species. Megafauna are so important, in fact, that some scientists have proposed reintroducing them to habitats where they once lived — either by actually cloning extinct species, or by bringing in their closest living relatives from (where else?) Africa.

While these measures may help restore some natural areas, they are no substitute for maintaining healthy ecosystems in the first place. Hopefully, the research being done by scientists like me and my colleagues today can be used in conservation efforts, to help prevent the next big megafauna extinction.

• South American megafauna image from jqjacobs.net.

Mighty microbes implicated in Permian mass extinction

Ninety-six percent of marine and 70% of terrestrial species died in the Permian mass extinction, which began about 252 million years ago and lasted for over 20,000 years. Geochemistry tells us that this extinction coincided with a severe and rapid change in the Earth’s carbon cycle, but this alone could not have been the cause of the extinction. Initially it was thought that carbon dioxide released by Siberian volcanism explained this change in the carbon cycle but the volcanic outgassing was not large enough to have been responsible for this big a disruption. So if not volcanoes, what could have produced so much carbon in the atmosphere?

A new study shows that the speed and exponential growth of carbon had to be of biological origin. The study proposes that the emergence of a new group of microbes, Methanosarcina, was responsible for producing the methane in the atmosphere that led to the extinctions. At around 250 million years ago, these microbes acquired fancy new machinery, or a new metabolic pathway through lateral gene transfer that made them capable of taking advantage of the large amounts of marine carbon produced at the time and converting it to methane. This also required large amounts of nickel that was released by the volcanoes. The new source of nickel, a limiting resource in the ocean, combined with increases in marine carbon created a feeding frenzy of bacteria. Following the production of methane by Methanosarcina, other microbes, anaerobic methanotrophs, turned the methane into carbon dioxide further lowering oxygen levels in the ocean.

Today we see similar short-lived low oxygen events in the ocean, but these are driven by algal blooms. Marine algae (i.e., marine plants) are responsible for most of the photosynthesis that occurs on the planet and the resulting oxygen and marine organic carbon. Just like the plants that grow in your garden, these algae rely on nutrients to grow and reproduce. When there’s a new source of otherwise limiting nutrients, they often grow rapidly and we call this a “bloom.” As the algae use up the nutrient source, they begin to die and microbial decomposition begins. These microbes consume oxygen in the water as they feed on the algae and release hydrogen sulfide gas as they have their own population explosion. Just as scientists have observed in the fossil record for the Permian extinction, we see low oxygen levels in areas of the ocean following algal blooms and increases in microbial digestion. The hydrogen sulfide gases released during decomposition of modern algal blooms often produce mass die-offs of marine animals.

Ulva releasing life history stages

Ulva releasing microscopic life history stages. Photo by Rosemary Romero.

I study microscopic life history stages of modern bloom-forming algae, green seaweeds in particular. These life stages are similar to invertebrate larvae in that they are released into the ocean by adults and can be carried long distances by waves and currents. Last spring I set out to learn how to detect these life stages in coastal waters using their genetic code, or DNA. I was hoping that I could use this method to predict when these seaweed blooms were more likely to happen. My first challenge was to find out if I could extract DNA from these life stages. I went to the rocky intertidal at the Romberg Tiburon Center (RTC) and collected some specimens of adult Ulva, the alga responsible for most of the worlds green seaweed blooms. I brought the algal specimens back to the lab and kept them dry, dark, and cold for a week. When I submerged the algae in artificial seawater they began to release what looked like green ooze. Upon closer investigation under a microscope this ooze proved to be microscopic swimmers, Ulva's tiny planktonic life history stage! I filtered this solution of swimmers to concentrate them and stored them in the freezer for DNA extraction at a later time. Just to make sure my procedure for DNA extraction would work for green algae, I extracted DNA from as many morphologically different specimens of adult Ulva I could find at RTC. These included specimens taken in small volume from the solution of swimmers and I filtered them on the the same day. After the extraction procedure I used a method called gel electrophoresis to test if I had successfully extracted DNA from my samples. This method works by adding a fluorescent dye that will bind to any DNA present and produce a glowing band under UV light. Unfortunately, the first four times I tried this, no glowing bands resulted. After taking a few more classes and working with other scientists that have experience extracting DNA from algae, I finally had a breakthrough. I successfully extracted DNA from the adult Ulva specimens I collected in December 2013. I’m still tying to figure out what went wrong with the filters, but I went back to RTC in April 2014 to do another survey of Ulva species. By the end of this spring I will be able to test for changes in Ulva species composition across different seasons.

Tracking down ammonites in the Denver, Colorado, area

In July 2013, I visited the Denver, Colorado, area to collect data from two collections housed at United States Geological Survey (USGS) facilities and the University of Colorado (CU) Museum of Natural History. The USGS collections are housed in the Core Research Center on the Denver Federal Center campus. The building is also a repository for a large collection of soil samples and approximately 1.7 million feet of drilled rock, sediment, and ice cores. The Museum of Natural History is located at the University of Colorado campus in scenic Boulder, Colorado.

Though these collections cover a wide range of organisms from all over the world, my purpose there was to visit the fossil collections from the Western Interior Seaway. The Western Interior Seaway was a widespread shallow sea that flooded the North American continent from the Gulf of Mexico to the Arctic Ocean during the Late Cretaceous Period (about 100 to 65 million years ago). My work focuses on the faunal dynamics associated with invasion into these shallow sea environments. By more closely examining natural experiments in the past when biota encountered widespread novel physical conditions, we can better inform our predictions of how organisms will respond to the rapid global change happening today.

To that extent, I was interested in photographing and documenting a portion of the vast numbers of ammonites the two institutions have amassed over the years. Ammonites are a completely extinct group of hard-shelled cephalopods, related to the modern-day squid, octopus, and nautilus. Their fossils are often sold in rock shops because their beautiful undulating suture lines make them aesthetically pleasing items. They were incredibly diverse and abundant during the time the Western Interior Seaway existed, and so are an ideal study group to explore the dynamics of this system.

Acanthoceras sp.

An Acanthoceras sp. specimen (UCM11843) collected from the Lower Cretaceous rocks in Colorado, now housed at the CU Museum of Natural History.

The large collection of Cretaceous bivalves, gastropods, and ammonites kept in the USGS collection is primarily the result of work done by USGS geologists, such as William Cobban, who collected and published on the Western Interior throughout the late 20th century and is still at the USGS facilities in Denver today. The collection contains drawer upon drawer of specimens. With the generous help of curator Kevin “Casey” McKinney, I photographed hundreds of ammonites, including many unpublished specimens. These photographs will be used to identify morphological features that may have influenced the degree to which ammonites were able to invade or adapt to the seaway. It was an adventure exploring the dusty cabinets, where every drawer held a surprise.

Drawer of ammonites

A drawer filled with nothing but ammonites at the USGS facilities.

After four days in the suburbs of Denver, I took a bus up to beautiful Boulder, Colorado, just 45 minutes outside of Denver proper. After winding my way through the University of Colorado-Boulder campus, I arrived at the Bruce Curtis Building where the museum collections were housed. Collection manager Talia Karim greeted me and helped me get set up before showing me around the collections housed in the basement. Here, there were not as many specimens as at the USGS, but they were no less impressive. During the next three days, I photographed about a hundred more beautifully prepared specimens before I had to say goodbye to the Denver area.

The richness of the collections were such that, no matter how often I visit, there will always be much more to discover. I have plans to return in the near future to continue my explorations of these amazing and underused resources.

Examining morphologic variation in varanid skulls through time and space

As a graduate student affiliated with the UCMP, there are many resources readily available to me. Not only does the museum have the largest university research collection, but the curators, museum scientists, and staff are some of the most knowledgeable and helpful anywhere. UCMP is recognized for taking care of its graduate students, and one of the ways they do it is by providing multiple funding opportunities. I applied to UCMP for funding last year in order to conduct museum travel for my research and I was fortunate to get an award from the Welles Fund.

One major aspect of my research focuses on looking at shape differences in the skulls of monitor lizards. Monitor lizards, or varanids, are generally thought of as being fairly large lizards (e.g., Komodo dragon), but some may be no longer than a pencil. Although there are many extinct species and genera within this group, there are approximately 70 living species in the single genus Varanus. They live in Africa, Southern Asia, and Australia, and are ecologically versatile, with some being strictly terrestrial, arboreal, or even semi-aquatic. Fossil varanids from Asia may be as much as 90 million years old; varanid fossils are also found in North America and Europe.

Two varanids

Left: A Komodo dragon (Varanus komodoensis) from the Cincinnati Zoo. Photo by Mark Dumont (CC BY 2.0). Right: The smallest monitor lizard, a neonate Varanus brevicauda. Photo courtesy of Eric R. Pianka.

Thanks to my Welles Fund award, last year I was able to visit the American Museum of Natural History in New York, The Yale Peabody Museum in New Haven, CT, and the Australian Museum in Sydney, Australia. At these museums I photographed the skulls of over 300 modern varanid skulls, getting top, side, and bottom views of each. I use these photos for a technique called Geometric Morphometrics. Morphometrics (greek “morphe” or shape, and “metria” or measurement) is a general term used for describing the quantification of shape. Many fields within biology use this technique to study numerous questions, like changes from juvenile to adult morphologies, how ecology influences shape, and in my case, comparing species from different regions to each other and to those in the fossil record. Geometric Morphometrics is a technique that uses landmarks (coordinates) placed on photos of specimens that can be regarded as a a similar point in each specimen in the study. There are various ways of analyzing the data, but essentially the locations of the landmarks on different specimens are compared and quantified. One main analysis conducted with this data is called Principal Component Analysis which tells you where the maximum amount of variation in your specimens happens to be. This allows the researcher to determine how much shape difference exists in their specimens of interest. In my case, museum visits are essential since they allow for adequate sample sizes to compare the species found in different locations of this group.

Varanid skull

Example of a Varanus skull with landmarks. Photo of AMNH specimen by Elizabeth Ferrer.

I was able to analyze the data to answer various questions, and one of the most interesting discoveries was that the varanids in Africa, where there are only about six species, are almost as morphologically variable as those in, for example, Australia where there are approximately 30 species (depending on where you designate certain groups). I am continuing to analyze and collect data, but I am thankful to the UCMP for providing the finanical assistance necessary for me to complete a large portion of my dissertation project. As a side benefit, traveling to distant museums allowed me to visit interesting and beautiful locations!

Freemantle Beach and Sydney Opera House

Fremantle Beach, Western Australia (left), and Sydney Opera House, Sydney, Australia (right). Photos by Elizabeth Ferrer.