UCMP's partnership with Point Reyes National Seashore (National Park Service) has resulted in the discovery and collection of an important marine mammal specimen. This specimen is currently being prepared by UCMP Research Associate Robert Boessenecker, and will be reposited at UCMP. Lillian Pearson, a Geoscientist-in-the-Park intern, is setting up protocols for the long-term monitoring of paleontological resources (fossils) at Point Reyes. Erica Clites did this type of work for the National Park Service before coming to UCMP, and has been advising Lillian on the project. For more information, read the full story.
On June 15, UCMP Curator and Integrative Biology Professor Tony Barnosky met with Governor Jerry Brown, Executive Secretary of the UN Framework Convention on Climate Change Christiana Figueres, and California climatologists at the Los Angeles County Museum of Natural History to discuss global warming and the consequences of failing to deal with it.
At a press conference following the meeting, Brown expressed his desire to reduce California’s greenhouse gas emissions by 40 per cent over the next 15 years and spoke of legislation mandating that 50 per cent of the State’s electricity come from renewable sources by 2050.
At the end of November, representatives from some 195 countries will gather in Paris for a UN Climate Change Conference in the hope of forging international agreements to limit greenhouse gases and combat climate change.
Every May for the past 30 years or so, the Girl Scouts of Northern California have celebrated the advancement of their scouts from Junior to Cadette status by a symbolic walk across the Golden Gate Bridge. Following this year’s May 2 event, the scouts continued on to Crissy Field where they enjoyed entertainment and information booths. And UCMP was there to celebrate with the scouts.
For the third year in a row, UCMP hosted a table staffed by an enthusiastic crew that included graduate student (and former Dutch girl scout) Renske Kirchholtes, undergraduates Gina Hwang and Alexis Williams, and Museum Scientist Erica Clites. The Girl Scouts and their parents enjoyed talking with current UC Berkeley students and seeing women role models.
A morphological study of living and fossil Quercus (oak) pollen from California using scanning electron microscopy
California has more than 26 oak (Quercus) species, many of which have widespread distributions and different habitats. For example, the California black oaks (Q. kelloggii) are distributed in foothills and low mountains (altitude ~4750 feet), while the Coast live oak (Q. agrifolia; altitude ~830 feet) lives near the coast. Palynologists study the distribution of plant pollen and spores in space and time, and changes in their assemblages reflect changes in regional and local vegetation.
In the study of past climates, palynologists have used oak pollen as an indicator of relatively warm environments. But in the examples given above, we see that the range of different oak species varies, so the temperatures in their respective habitats must vary as well. If palynologists treat all the oak species the same — as indicators of a "warm environment" — could this lead to wrong interpretations of the environmental conditions? If the answer is yes, why do palynologists still treat all the oak species the same?
This question could be answered if we resolve a basic problem in pollen taxonomy: how to distinguish between the pollen of different oak taxa. All oak pollen have similar characteristics: three colpi (furrows) and a verrucate surface (small surface features under two microns). Even the ratio of length and width of each species overlaps. These nearly uniform morphological features make identifying oak pollen very difficult at the species level, at least using Light Microscopy (LM).
I am studying pollen samples from Clear Lake to understand climate and vegetation change in California during the last interglacial period (~120-80 kyr ago). See earlier blogs: Dispatches from Clear Lake, part 1 and part 2; California pollen taphonomy and pollen trap study in Clear Lake, California. After studying the lower part of a 150-meter-long lake core that includes sediments from the interglacial period I'm interested in, I found two distinct oak pollen numerical peaks. Before categorizing all oak pollen in the samples as "indicators of warm environments," I would like to know which species of oak they represent. Since it's so difficult to detect morphological differences using Light Microscopy, I wondered if I could identify more diagnostic features on pollen grains using Scanning Electron Microscopy (SEM). Serendipitously, a paper was published on how to use SEM and quantitative analysis to identify grass pollen at the species level. Like oak pollen, grass pollen is also difficult to differentiate using LM identification. Thinking that the methods described in the article could be applied to oak pollen identification, I decided to take SEM images of California oak pollen to see if a systematic identification method could be developed. Then, I'd use quantitative analysis methods to identify the oak species in my Clear Lake interglacial samples and see if there were particular taxa appearing and/or disappearing in the area during times of climate change.
Last summer (July, 2014) I visited Dr. Luke Mander, author of the grass pollen paper, at the University of Exeter, UK, to investigate the possibility of identifying oak pollen using SEM and computer statistics. In an SEM lab, I took 70 images of pollen from 23 extant California oak taxa and 150 images of fossil California oak pollen.
A preliminary analysis has already revealed that at least three pollen wall morphotypes, two of which represent habitat-specific oak types, can be recognized in extant California oak species. Most specimens in Type-1 represent shrub oaks, adapted to dry environments. Type-3 pollen neatly matches specific phylogenetic lineages. We were able to assign the fossil oak pollen from Clear Lake to the three categories of extant California oak pollen. Interestingly, the change in oak pollen groups in Clear Lake sediments suggests species replacement during the start of the interglacial period. I have found that more precise and objective identification of oak pollen types is possible using automated digital image analysis algorithms and a larger training set of SEM photographs of pollen from known species, so I will be working on that in the Fall. I hope to amass more detailed vegetation analyses for past periods of climate change.
All photos courtesy of Winnie Hsiung.
It's April 18, 2015, and I am sitting in a room at the Charles Motel in Truth or Consequences, New Mexico, the same apartment-style room that I have stayed in during the past four years of field work. Time sure has passed by quickly; from my first paleontological dig as an undergraduate at Texas State University-San Marcos under Dr. Gary Upchurch, to my ambitious inaugural self-guided field trip as a first-year graduate student at Berkeley, to last year's even longer field excursion, and finally to this short trip with my advisor, Cindy Looy. What keeps bringing me back to this area is an exceptional Late Cretaceous flora in the Jose Creek Member of the McRae Formation—this flora is the foundation of my dissertation work.
I am interested in the functional diversity (the range of plant ecological strategies) of Cretaceous forests in warm-wet climates. Cretaceous floras often contain a mix of plants that are no longer seen in association today. The Jose Creek assemblage, for example, includes both palms and redwoods. These non-analog communities can be difficult to understand from the perspective of community ecology, because we cannot make inferences about their ecology based on similarities in taxonomic composition with modern floras. The difficulty of understanding past communities is compounded by the paucity of fossil deposits preserving a "snapshot" of a forest in relative growth position. This is precisely why the Jose Creek deposit is so unique—it contains a flora preserved in a volcanic ash airfall. During my 2013 field season, we traced a single-horizon ash layer for approximately 1.2 km (see previous blog). Such an extensive deposit makes reconstruction of the forest, including lateral variation in forest structure, possible. Because the volcanic ashes are fine-grained and deposited rapidly, the plant parts (leaves, fruits, flowers, seeds, cones, etc.) are very well preserved. I am using morphological features of these plant fossils—and an explicit ecological and spatial sampling scheme—to reconstruct the forest. My ultimate goal is to evaluate the ecological diversity of the community, and to understand how forests in warm-wet climates have changed since the Late Cretaceous.
This is what brings me to Truth or Consequences this April—a continuation of my quest to describe this incredible flora. This trip is a short one—only four days—with two simple missions: (1) "cherry picking" well-preserved leaf specimens to use for trait measurements (for inferences of their ecology), and (2) hunting for cones to finish a whole-plant description of an extinct redwood that is abundant in the deposit.
Last June's trip (2014) was more intensive. I drove to New Mexico with two undergraduates—James Buckel and Negin Sarami—and recent IB graduate/Looy Lab veteran, Stephanie Ranks. We spent two weeks working at the site, establishing new collecting quarries and re-sampling the 12 small exploratory quarries from the previous year, effectively doubling their size. All in all, we have now established 17 quarries that span the length of the exposure! We successfully employed a new data collection method in the field, which had several advantages over the previous year. During the 2013 collecting trip, we collected and brought back to the UCMP all of the specimens excavated from each quarry. This generated a large amount of material very quickly—the maximum that our extra-long SUV could carry. In contrast, during the 2014 trip we looked at all our excavated specimens, comparing them with a leaf morphotype guidebook of over 120 different leaf types that I created from the previous collections. Using the book as a guide, we were able to record the number of occurrences of each morphotype, as well as their percent cover of the rock surfaces, without having to bring every specimen back to the museum. Of course, we did collect the specimens that were very well-preserved or that represented new morphotypes. By adopting this method in the field, we were able to collect far more data than would have been possible by only making collections and still bring back a full load of really nice specimens to the museum.
The flora has proven to be extremely diverse, with new morphotypes being found every day. The variation in morphotype composition from quarry to quarry also suggests a very structurally diverse flora. This is an incredible site to work, never a dull moment! I am really looking forward to the next big trip, and consider myself extremely lucky to receive the support of so many organizations, especially the UCMP and its amazing community of researchers, staff, and donors. Now, back to the field site before I lose any more daylight—Cindy and I still have a day of "wow" moments ahead of us before we return to Berkeley!
Organizations that have generously supported this work include:
— UCMP Graduate Student Award, University of California Museum of Paleontology, 2013 and 2014
— Geological Society of America Graduate Student Research Grant, 2014
— Integrative Biology Graduate Research Fund, 2014
— Sigma Xi Grants-in-Aid of Research, UC-Berkeley Chapter, 2014
— Mid-American Paleontological Society (MAPS) Outstanding Student Research Award, 2013
— GRAC Research Funds, UC-Berkeley Integrative Biology Department, 2013
Occurrences of green tides have been on the rise in recent years worldwide. The most impressive have been reported off the coast of China in the Yellow Sea. In August 2014, the Monterey Bay area experienced a green tide that resulted in the accumulation of the macroalgae, Ulva, on its beaches. Algal blooms often make the headlines in spring and summer yet they are not a new phenomenon. In fact, toxic algal blooms may have been responsible for bird, fish and marine mammal die-offs recorded in the fossil records of Chile's Neogene and Gulf Coastal Florida's Pliocene. Blooms are typically considered to be an indication of decreased ocean health and pollution but there are many other factors that contribute to algal blooms. While Ulva itself doesn't produce toxic chemicals as it grows, the bacteria that decompose the alga once it begins to die can suck the oxygen from the surrounding seawater, suffocating other marine life.
Environmental factors necessary to generate an algal bloom include:
— High nutrients
— Calm water
— Few grazers or predators
I've been interested in learning more about why we see green tides when we do. To do this, I've been focusing on the microscopic reproductive stages of the green-tide-forming algae, Ulva. In July 2014 I began collecting two liters of seawater every month from San Francisco Bay. I divide the water into culture flasks, add nutrients important to algal growth—such as nitrate, phosphate, ammonium, trace metals and vitamins—and culture it in environmental chambers on the UC Berkeley campus. These chambers are set to simulate summer conditions (16°C, 12-hour days) and every week I replace the seawater with fresh nutrient-enriched seawater. After four weeks I find young Ulva blades and tubes growing on the bottom of my culture flasks. Since I know the volume of the water I originally put into the flasks, I can estimate the number of propagules per liter that were present at the time of collection. I've been repeating this sampling at an additional four locations within San Francisco Bay once every season to estimate variation in spatial distribution of these reproductive stages.
Every cell in adult Ulva (blade or tube) has the potential to become reproductive, releasing up to 16 swimming spores from each cell. The cells along the margins of the blades usually become reproductive first; you can see the difference in color between the reproductive cells and vegetative cells in the image at right, below.
Along with the help of some UC Berkeley undergraduates, I am also tracking the settlement of young Ulva at my field site in Tiburon. We have attached settling plates made of resin to rocks in the intertidal zone near the Romberg Tiburon Center. These settling plates are submerged at high tide and exposed at low tide. Each month we return to the intertidal at low tide to collect the plates covered in algae and replace them with sterilized plates. Once back at the lab we use a dissecting microscope to estimate the amount of young Ulva growing on the plates. Now we are working on comparing the amount of young Ulva that grows in the cultures to the patterns of young Ulva we are seeing on the settling plates.
All photos courtesy of Rosemary Romero.
Annual field trips used to be something of a tradition at UCMP, but that tradition faded once the Department of Paleontology merged with other units to become the Department of Integrative Biology in 1989. In recent years, former UCMP Director Jere Lipps organized and led three field trips: Baja in 2001, southern California in 2008, and Oregon in 2009. And now two of UCMP’s newest curators, Assistant Professors Seth Finnegan and Cindy Looy, are trying to revive the annual field trip tradition. Seth organized and led a trip to the Kettleman Hills and Death Valley in 2014, and this year, he and Cindy led one to southern California during Spring Break, March 21-28.
On March 21, Seth, Cindy, three UCMP staff (Lisa White, Dave Smith, and Erica Clites), and 11 grad students headed south from Berkeley, with their first stop being a locality south of Soledad along Arroyo Seco Canyon in Monterey County. Here, the group had their first look at the rocks of the extensive Miocene Monterey Formation and found pea crabs, bivalves, and brachiopods. The group would visit more exposures of the Monterey Formation along the California coast — at Gaviota State Park and El Capitan State Beach, west of Santa Barbara — and even as far south as Newport Bay.
At Piru Gorge, just off I-5 south of Tejon Pass, an attempt was made to relocate some plant localities reported by UCMP alum Daniel Axelrod (A.B., 1933; M.A., 1936; Ph.D., 1938), but without success. East of the gorge and the highway, some road cuts exhibiting nice geological features (cross bedding, ripple marks, etc.) were examined.
Jere Lipps — current Director of The Cooper Center, the fossil repository for Orange County — gave the group a tour of the Cooper facility. Afterwards, Jere took the group to a number of interesting localities in the Newport Bay area, including a visit to the Upper Newport Bay Nature Preserve with outstanding views of marine terraces. At the end of the day, Jere and Susie Lipps had the group to their home for a barbecue.
Anza-Borrego Desert State Park, east of San Diego, was the next stop. The group spent two days looking at the geology exposed at Split Mountain and along Fish Creek Wash in the southeastern corner of the park. The rocks along the wash told some very interesting stories. Moving from east to west, the group examined cobble-filled layers believed to have been deposited by flash floods. Farther on, the rocks showed where an underwater landslide buckled unlithified ocean sediments. Close to the western end of Split Mountain, a series of turbidites — underwater sediment flows that result from slope failures at shelf margins or the distal edges of large river deltas — were observed. Even farther west down the wash, many layers of nearly equal thickness were suggestive of sands deposited out on a vast river delta of shallow slope.
From Anza, the group headed to the Sonny Bono Salton Sea National Wildlife Refuge on the southeast shore of the Salton Sea. Here the group had an initial look at the lake’s beaches covered with dead barnacles and the bones of fish and birds. After a stop to admire some mud volcanoes near one of the 11 geothermal power plants located around the southern end of the Salton Sea, the group headed to the hills above Mecca at the north end of the lake. The group spent its final night in Painted Canyon after taking a hike through it and an adjoining slot canyon.
After a morning look at some roadside exposures of delta deposits, the group made the long drive back to Berkeley. All participants thoroughly enjoyed the trip and Seth and Cindy are already pondering where to go next year. Will it be the Great Basin? Channel Islands? Italy anyone?
The Bearded Lady Project: Changing the Face of Science came to the UCMP in February, one of many stops in a photographic journey made by documentary film makers seeking to educate the public on gender inequities in geoscience fields, particularly in paleontology. Women of the UCMP sat for portraits that will become part of a photography series intended to celebrate adventurous women who are true pioneers in the fields. See if you can recognize some of your favorite women of the UCMP!
If you have taken the elevator to the top of Sather Tower, aka the Campanile, perhaps you've heard that some of the floors of the tower are filled with fossils. This is not a campus myth, it's fact!
The Campanile is celebrating its 100th anniversary this year and its very first occupants — moving in before the tower was even completed — were fossils. At that time, the museum and Department of Paleontology were in Bacon Hall, just east of the Campanile, so as a storage facility, the tower was conveniently located. Although the museum has moved several times over the past century, the fossils in the Campanile have not.
Some of the first fossils to be moved into the tower were vertebrate bones from John C. Merriam's excavations at the Rancho La Brea tar pits. These bones, collected prior to 1914, occupy four of the five floors devoted to fossil storage. But the Campanile houses several other collections too. There are bones collected in the 1930s from asphalt deposits in McKittrick (about halfway between San Luis Obispo and Bakersfield) and nearby Maricopa; mammoth bones, teeth, tusks, and other miscellaneous Pleistocene fossils; modern whale bones; a few blocks containing ribs of the plesiosaur Hydrotherosaurus alexandrae; crates containing plaster casts of dinosaur footprints and trackways that were made by Sam Welles while doing field work in the Kayenta Formation of Arizona; petrified wood from the Petrified Forest; fossil plants; invertebrate fossils, including collections moved to the Campanile from McCone Hall and some from Triassic rocks in Nevada; Upper Cretaceous leaves from Bryce Canyon, Utah; oil company collections of microfossils (bulk samples) and invertebrates; casts of mastodont skulls; an ichthyosaur skull; some sculptural reconstructions (including a glyptodont); and cases of reprints. A conservative estimate of the number of fossils stored in the Campanile, excluding the microfossils, is 300,000.
During this year-long celebration of the Campanile, it is only fitting that the fossils housed there receive some attention too. We will periodically post blogs throughout the year to discuss some of the ongoing research projects that involve the Campanile's fossils. For instance, UCMP Curator and Associate Professor of Integrative Biology Leslea Hlusko and her lab have two projects underway and Eric Holt, an undergrad in Tony Barnosky's lab, is looking at wolf morphometrics. And back in September we announced the grant award from the Institute of Museum and Library Services to curate the Campanile's McKittrick fossils. To date, more than 2,500 specimens have been cleaned and cataloged, and more than 500 images of 273 specimens have been added to CalPhotos.
Stay tuned for more about the Campanile's fossil treasures!
On November 1, UCMP participated in Discovery Days at AT&T Park, the closing event of the annual Bay Area Science Festival. The museum has been a Science@Cal exhibitor at the Festival for four years running. This year, over 30,000 people enjoyed 200 free activities and exhibits at the Festival, a “science extravaganza.” The Festival is meant to entertain and inspire; it’s where visitors can unleash their inner scientist.