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UCMP volunteers discover important specimen

Kathy Zoehfeld, holds her palm out to show the gastropod speciment she discovered.

UCMP volunteer Kathy Zoehfeld holds a tiny gastropod she and volunteer Don Pecko discovered in the former USGS Menlo Park collection.

UCMP volunteers Kathy Zoehfeld and Don Pecko recently discovered a type specimen from the Smithsonian National Museum of Natural History among the hundreds of thousands of fossils in the former USGS Menlo Park collection. This type specimen, a tiny gastropod called Ceratia nixilia, was discovered in a drawer of fossils they were rehousing into new archival boxes. Don and Kathy not only noticed the less than a centimeter long gastropod, but brought it to my attention because they noticed the number written on the specimen. Noticing the green diamond also affixed to the fossil, we looked it up in the National Museum of Natural History database and discovered that it was listed as a holotype specimen.

Holotypes are the most important examples of a species, and the specimen that future researchers always return to determine whether their fossil is indeed the named one. Although some type specimens are lost due to disasters like the 1906 earthquake that destroyed much of the California Academy of Sciences collection, sometimes they are simply misplaced.

The U.S. Geological Survey had a close relationship with the National Museum of Natural History, and their offices housed in the same building for decades. Perhaps the specimen was accidentally transferred with the Pacific coast collections when the USGS Menlo Park office opened in the 1950s? Or perhaps it was sent out on loan to one of the paleontologists in the Menlo Park office and never returned?

Regardless of its journey, it eventually reached the UCMP, where my sharp-eyed volunteers signaled it out. The specimen will be returned to the National Museum of Natural History in Washington D.C. and again be made available for researchers. This discovery shows the true value of rehousing a collection because it requires handling every single specimen and often results in lost specimens being returned to their proper location.

We are grateful to the National Science Foundation for the funding to complete this worthwhile project. I am lucky to be working with volunteers as dedicated to returning every fossil to its proper place as I am.

Ceratia nixilia, a small gastropod or sea snail, was discovered mixed with other specimens as the volunteers were rehousing a drawer of fossils.

Ceratia nixilia, a small gastropod or sea snail, was discovered mixed with other specimens as the volunteers were rehousing a drawer of fossils.

Landscapes change forever when large mammals disappear

An African elephant grazing among trees.

An African elephant grazes. Photo credit: Tony Barnosky

Research on the extinction of large mammals by members of the Barnosky Lab and their colleagues highlights how entire landscapes are affected when modern elephants and their extinct relatives, mastodons and mammoths, disappear.  From plants that are no longer grazed to fewer nutrients in soils, the loss of megafauna significantly impacts ecosystems in a dramatic fashion as detailed in recent articles and interviews.

Learn more about this recent research:

 

Five Climate Tipping Points We've Already Seen, and One We're Hoping For

forestfireThis week is Climate Week in New York, when President Obama, Pope Francis, and many other world leaders converge to continue hammering out commitments intended to limit global warming to 2 degrees C or less, to be presented at the make-or-break COP21 climate meetings in Paris in early December.

The commitments are not there yet--so far those on the table would allow enough greenhouse gas emissions to raise temperature 3 degrees C or more. But staying below 2 degrees is critically important, for we already are seeing climate-triggered problems arise, even though global temperature has only risen less than one degree (0.9 degree C) above what used to be normal, and indeed what human civilization evolved in.

Read the rest at Huff Post Science Blog

UCMP and Stanford partner on a global change workshop for teachers

Teachers Monica Sircar (left; Everest Public High School, Redwood City) and Crystina Ayala (ASCEND K-8 School, Oakland) use string to represent rays of sunlight hitting Earth's surface at different angles at different latitudes.

Teachers Monica Sircar (left; Everest Public High School, Redwood City) and Crystina Ayala (ASCEND K-8 School, Oakland) use string to represent rays of sunlight hitting Earth's surface at different angles at different latitudes.

Middle and high school science teachers received double the resources when UCMP and Stanford's School of Earth, Energy & Environmental Sciences teamed up to offer a week-long workshop on global change.

Read more about the workshop on Stanford's blog

UCMP science casual: Dinosaur NightLife at the California Academy of Sciences

Imagine over 3,000 adults in San Francisco’s California Academy of Sciences (Cal Academy) for a night of fun special exhibits, drinks, and a serious science social. Now imagine it every Thursday. On July 23rd a dinosaur-themed Cal Academy NightLife event called upon volunteers from UCMP to showcase and explain the mysteries of these monsters beside their contemporary chews.

The NightLife also featured a tour of Cal Academy’s library archives about the historic “Bone Wars” between Victorian paleontologists Othniel Charles Marsh and Edward Drinker Cope and a showing of the 1993 classic Jurassic Park in the Tusher African Hall. Indeed, there was something uncannily familiar about watching the Dilophosaurus scene from Jurassic Park amongst stuffed African lions and cheetahs, who had also certainly taken their fair share of prey during life.

The event runs every Thursday from 6-10pm and requires a 21+ photo ID for entry. Stay tuned for the next time UCMP crosses the bay for another paleo-themed NightLife gathering!

New research shows how mammals became smaller in response to dramatic climate warming

Lead author Brian Rankin holds jaws of two species of 50 million year old horses.  Measurements of their teeth were used to study how global change can affect how mammals evolve.

Lead author Brian Rankin holds jaws of two species of 50 million year old horses. Measurements of their teeth were used to study how global change can affect how mammals evolve.

Fifty-six million years ago the Earth underwent a dramatic warming event, with temperatures increasing by as much as 7° Celsius over a span of just 100,000 years. Many mammals responded to this temperature increase by becoming much smaller. How these changes happened, however, is poorly understood. Identifying and measuring the mechanisms that drove these changes was the focus of a new study by University of California Museum of Paleontology researchers Brian Rankin and Pat Holroyd, and colleagues from University of Calgary and Western University of Health Sciences.

Lead author Brian Rankin, the newest postdoctoral scholar of University of California Museum of Paleontology, explains "When temperatures get warmer, we see a wide range of mammals become smaller. Determining what evolutionary processes are responsible for these changes and how much each contribute to this pattern has been very uncertain. We chose the evolution of mammals at the Paleocene-Eocene boundary because it is a time of dramatic global warming when many different types of animals became dwarfed and the fossil record of this time is incredibly rich."

In a new paper published in Proceedings of the Royal Society B, these researchers present a new method to separate and quantify body size change due to selective extinction vs. change within lineages to determine which is the most important way in which evolution takes place during times of global warming. They found that that some evolutionary mechanisms (i.e., species selection) might act differently during global warming events, favoring mammals that increase in size rather than decrease. The methods developed in the paper can now be broadly applied to look at evolutionary change during other times of global change.

Partnership with Point Reyes National Seashore leads to important discovery of marine specimen

ptreyes-fossilUCMP'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.

Barnosky meets with Governor Jerry Brown and a United Nations delegation to discuss climate change

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.

Brown et al

Behind Governor Brown (at the podium) are (from left) Christiana Figueres, Liz Hadley, and Tony Barnosky. Photo courtesy of Tony Barnosky.

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.

See past blog posts dealing with Tony’s involvement with climate change issues.

UCMP participates in Girl Scouts’ “bridging” event

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.

Renske and Alexis

Graduate student Renske Kirchholtes and undergraduate Alexis Williams talk with members of a Girl Scout troop at Crissy Field. Photo by Erica Clites.

Alexis and Gina

Berkeley undergraduates (and UCMP employees on the USGS project) Alexis Williams (left) and Gina Hwang show fossils to eager Girl Scouts. Photo by Erica Clites.

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.

Oak pollen

Oak pollen grain

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.

Winnie with SEM

Winnie using the Scanning Electron Microscope.

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.

Pollen wall morphotypes

The three pollen wall morphotypes.

All photos courtesy of Winnie Hsiung.