May 2018: Paleobotany

Spring is coming along nicely at the Museum. We’re super excited about our blooming garden and growing programs related to native plants. For May’s Collection Close-Up, we have arranged a tour of our fossil plant garden. Rather than heading outside, this garden tour will take us into the paleobotany shelves of our paleontology cabinets.

Paleobotany, or fossil plants, is an interdisciplinary field relying on both botanical and geological expertise to investigate questions related to the evolution and natural history of plants. By studying fossil plant material, paleobotanists learn about the ancient organism and also delve into questions such as whether the specimen has close living relatives, how the fossil’s anatomy compares to that of modern plants, what the specimen can tell us about the relationship of different layers of rock and what the specimen can tell us about the the environmental conditions in which it lived.

Not all plant material is resilient enough to be preserved; often it decays or is consumed before it can be buried (and be on its way to fossilization). As a result, plant fossils typically consist of parts of the plant — most commonly, individual leaves or stem pieces. They are also often  preserved as imprints of the original specimen in the rock which holds them instead of preserved material itself. There is still surprisingly a lot of information you can gleam from incomplete fossil plants — from size and shape of the fossil to specific structures, such as veins, thorns and even individual cells under the right magnification.

Here are some of the beautiful specimens from our fossil garden and the stories they tell:

Cordia leaf

Cordia leaf (Monterey Formation, Miocene epoch). Leaf fossils are the most common macroscopic remains of plants. With its clear leaf shape and veins, this specimen can be identified as a member of the Cordia genus.

Stem

Stem (Monterey Formation, Miocene epoch). This impression of a stem was found by a Soquel High student in the 1970s. If you look at it closely, you can see the impressions of the plant’s thorns, which are identified in this image by white arrows.

Annularia leaf

Annularia leaf (Francis Creek Shale, Pennsylvanian epoch). This distinctive whorl of leaflets along a stem belongs to a member of the extinct Calamites family, a tree-like relative of modern horsetail plants. This specimen is one of several in our collection (like the one below) from the Francis Creek Shale, a famous fossil locality known for its unusual preservation of soft-tissued organisms within rounded nodules of rock.

Fern leaf

Fern leaf (Francis Creek Shale, Pennsylvanian epoch). This beautiful impression of a fern is another great example from the Francis Creek Shale. Both fossil ferns and sphenopsids (like Annularia above) are commonly found within the rock formation, as are a wide variety of uniquely preserved land and marine fauna.

For a closer look at these fossils, as well as other exhibits and gardens, stop by the Museum through June to look our Collections Close-Up.

April 2018: Ward’s Natural Science Establishment

A natural history museum collection is as much a collection of methods as it is a collection of objects. We learn a lot by looking at these forms of collection, and we benefit from the many local individuals who have contributed their personal materials, their eye for detail, and their passion for the natural world to our museum. Oftentimes our artifacts and specimens connect us to the broader stages of science and history, whether it be our founder Laura Hecox’s correspondence with a Midwestern scientist or the Smithsonian borrowing materials from our ethnographic collections. In our entomology collections, we find specimens that not only represent entomological diversity but also connect us to the history of a natural sciences institution that has played a major role in science education for years: Ward’s Natural Science Establishment.

Ward’s Natural Science Establishment was founded in 1862 by 28 year-old Henry Augustus Ward. Ward was a lifelong student and enthusiast of the natural world, having begun his first collection, a set of geology specimens, at the age of 3. As a young man he took off from the States to travel the globe, gathering specimens all the while. He would even sell fossils he collected to further finance his education in geology. This entrepreneurial spirit served him well, and led to the collection commissions that provided the foundation for Ward’s Natural Science Establishment. Notable collection endeavors include Ward’s stunning fossil, mineral and meteorite display at the 1893 World’s Fair, which was purchased by Marshall Field and donated to what would become the Field Museum in Chicago. During their heydey as a museum’s collections supplier, which lasted through the early 1940s, Ward’s employed many scientists to collect, identify, and prepare their specimens.

While Ward’s was historically known as a premier purveyor of fossils and minerals, their collections products extended into all branches of natural history, including the entomological displays that are this month’s Collections Close-up. Purchased from Ward’s in the 1930s, we’re looking at two displays: “North American Butterfly Chrysalids” includes a chrysalis each of Black Swallowtail, Silver-spotted Skipper, Mourning Cloak, Cabbage, Red Admiral, and Monarch Butterflies. These specimens represent the third stage of the butterfly life cycle, at which point the fully grown caterpillar sheds its exoskeleton to reveal the chrysalis, or pupa, which then hardens to provide a protective shell within which its body will undergo metamorphosis into a butterfly. This stage can last for a few days or up to a year depending on the species.

Our other feature is the display “Protective Nests and Cases made by Insects,” featuring the Orizaba Silkmoth cocoon, Mud Dauber nest, Bagworm bag, Caddisfly case, Mantis egg case, and Acacia Ant with hollowed out thorn. These specimens show greater variance, in that some are cases insects produce whereas others are natural elements insects utilize, and they also show the change in naming, both common and scientific, that can occur as our understandings of insects change: the “orizaba silkworm cocoon, Attacus orizaba” is now referred to as the Orizaba Silkmoth, Rothschildia orizaba.

Alongside their product catalogs, Ward’s also produced bulletins and guides, such as “How to make an insect collection.” Containing a range of information on capturing, breeding, and preparing specimens, the book reflects the company’s overall interest in educating people to do good science: “A job worth doing at all is worth doing well, and a scientific collection of insects cannot be obtained unless certain fundamental methods are followed.” You can find this guide through the Biodiversity Heritage Library repository of digitized biodiversity texts.

Over the years Ward’s Natural Science Establishment has transitioned from primarily serving the collections needs of the museum industry to Ward’s Science, serving the classroom needs of schools and colleges and offering everything from classic educational specimens to AP science activities. Nonetheless, Henry Ward’s passion for engaging natural materials in public displays lives on in museum collections far and wide, from fossils in the Field Museum to chrysalids here in the Santa Cruz Museum of Natural History.

 

March 2018: Echinoderms

Starting in March, the Museum is premiering a new blog by Collections Specialist Kathleen Aston called Collections Close-Up, which will feature items from our Collections that are rarely, if ever, on display. In addition to featuring the items in our newsletter and on social media, the Museum will display the items in our galleries in a special exhibit that will change each month.

For March, we are taking a closer look at the Museum’s echinoderm or “spiny skinned” animal collections. Phylum Echinodermata consists of more than 6,500 living species that can be divided into five classes, including sea stars, sea urchins, sea cucumbers, sea lilies/feather stars, and brittle stars. They tend to exhibit a characteristic five-sided, radial symmetry, with arms radiating out from a central body disk. Echinoderms have a unique water vascular system which carries liquid throughout their bodies in a series of tubes, and achieves movement through hydraulically driven tube feet. Additionally, echinoderms have mutable connective tissue, which allows their bodies to quickly transition between rigid and pliant states, meaning they can maintain a variety of postures with no muscular effort.

Now, sea stars like the ones you can find in our touch pool belong to the Class Asteroidea, meaning star-like. Here we are taking a closer look at Class Ophiuroidea, whose name comes from the ancient Greek word for serpent. Members of this class are commonly called brittle stars for the fact that their arms, which regenerate, easily break when caught.  Brittle stars are the most abundant echinoderms, and outnumber sea stars both in number of species and number of individuals. They are often found in thick carpets along the ocean floor, where they tend to feed on small organic particles. In comparison, sea stars tend to feed on relatively larger prey such as clams or snails. Though similar looking, brittle stars structurally differ from sea stars in several ways. Perhaps the easiest distinguishing feature is that while the arms and body of sea stars tend to merge gradually into one another, the long and snake-like arms of brittle stars are distinctly off-set from the disk of the body.

One representative of class Ophiuroidea in our collections is this individual Amphiodia occidentalis (above right), which was collected in Pacific Grove in 1939. First described in the 1860s, this species of long-armed brittle star clearly shows the snaky and sinuous arms attaching to a distinct body disk. As this species has been observed on the Central Coast to avoid areas with wastewater, it can be used as a bioindicator for water quality.

But Class Ophiuroidea has more to offer: basket stars. In basket stars, like this Gorgonocephalus eucnemis (above left),  the creature’s five arms are branched into smaller and smaller subdivisions that give the impression of a tangled basket or nest. Once prey is trapped in these branches, it is immobilized by a secretion of mucus and slowly coiled by the branches to the basket star’s mouth. Basket stars are cold-water creatures, and are found in the Arctic and Antarctic oceans as well as the deep-sea worldwide.

In museum collections, echinoderms are generally preserved as dry specimens when they are going to be studied for skeletal examination. Wet specimens, or preservation in alcohol-based fluids, are preferred for the study of soft tissue, but are also more generally versatile. Modern methods of collecting and preserving echinoderms encourage video documentation prior to preservation, to better capture information regarding behaviors like locomotion and feeding.