Finnish moth species is asexual with benefits

In central Finland there is a group of moths whose common name is bagworm moths because the larvae, or caterpillars, live in bags that they make from leaves and twigs. What’s even more noteworthy about these moths is that for many species males are unnecessary.

Bagworms belong to the family Psychidae which includes species living side-by-side in Finland that reproduce either sexually or asexually. This make these moths ideal for studying the ecological and evolutionary benefits of parthenogenesis—when a female’s eggs develop without being fertilized by a male, or asexually.

A wingless female bagworm moth (Dahlica fennicella) and its homemade case. Right, pupal remains. Image: Veronica Chevasco, © Veronica Chevasco

Sexual reproduction increases genetic variation and is thus central in evolution. However, what the parthenogenic bagworms are revealing is that asexuality may not be as limiting to a species’ survival as some have thought.

In fact, my research with bagworms shows that asexuality can be an adaptive advantage rather than an evolutionary dead end.

For example, by being parthenogenetic it appears that the bagworm species Dahlica fennicella is less vulnerable to wasp parasitism than related sexually reproducing moths.

It could be that behavioural differences between sexual and parthenogenetic species help D. fennicella avoid parasite attacks. It’s also possible that D. fennicella is successful because its offspring are not genetically identical clones, and with four sets of chromosomes, the multiple gene copies might overcome harmful mutations and even some parasitism.

Male bagworm moth (Dahlica fennicella). Image: Veronica Chevasco, © Veronica Chevasco.

Sexual and parthenogenetically reproducing moths look remarkably alike and so species must be identified using molecular methods, such as DNA barcoding. This molecular identification of sexual species shows that the parthenogenetic D. fennicella moth is a truly an asexual species, not a hybrid produced through the cross-breeding of two species of sexually reproducing bagmoths.

(A) Bagworm larvae and their cases made from leaves and twigs. (B) A wingless, sessile female rests on her pupal case waiting for a mate. (C) A sessile, parthenogenetic bagworm moth. (D) A wasp that parasitizes bagworm moths. Image: Veronica Chevasco, © Veronica Chevasco

These bagworm moth findings don’t minimize the importance of sexual reproduction; parthenogenetic species generally evolve from sexual species and inherit diversity from their ancestral forms.

But the results do show that, among bagworm moths, parthenogenetic species appear to avoid the costs of sex while getting benefits from an asexual life.

Collecting diatoms in sunny Italy: Citizen scientist brings specimens for museum’s collection

Last autumn I went on vacation with my brother to sunny Italy. Along with marvelling at St. Peter’s Basilica and eating great food, I did what any other keen museum volunteer would do: collect Italian freshwater diatoms for the museum’s collection.

Clockwise from top-left: St Peter’s Basilica, Vatican City; gondolas in Venice; Pompeii with looming Mt. Vesuvius; Valley of the Temples, Agrigento, Sicily; citizen scientist Joe Holmes beside the Silvestri Crater, Mt Etna, Sicily; Isle of Capri and Tyrrhenian Sea. Image: Joe Holmes © Canadian Museum of Nature.

Diatoms are fascinating, microscopic, one-celled algae, with a thin silica shell, measuring just five to 150 microns, or millionths of a meter.

Rome’s Tiber River looking toward the Sisto Bridge and St Peter’s Basilica. Two samples were taken here. The collected diatoms indicate alkaline pH, some brackishness, and moderate levels of organic nutrients. Left: Tryblionella constricta (36 µm x 6 µm). Second: Ulnaria acus (68 µm x 5 µm). Third: Frustulia vulgaris (44 µm x 10 µm). Right: Gyrosigma acuminatum (145 µm x 17 µm). Image: Joe Holmes © Canadian Museum of Nature.

These free-floating phytoplankton are the foundation of the aquatic food web, converting sunshine into stored chemical energy, and carbon dioxide into oxygen. Diatoms are found in all fresh and marine waters. Biologists use them for water quality analysis and climate change research.

Florence’s Arno River Dam where a sample was taken at lower left. Top: Aulacoseira granulata (40 µm x 6 µm). Bottom-left: Gomphonema pala (23 µm x 10 µm). Middle: Diatoma vulgare (53 µm x 13 µm). Right: Encyonema prostratum (44 µm x 18 µm). Image: Joe Holmes © Canadian Museum of Nature.

Whenever I had free time during the trip, I collected various types of diatom samples, amassing a total of 41 from lakes, rivers, fountains and ponds across Italy, including Rome, Florence, Venice, and Sicily.

An irrigation canal near Pomposa on the Po River Delta. The diatoms were sampled using a mud retriever. They reveal the presence of higher levels of organic nutrients, likely from agricultural runoff. Left: Bacillaria paxillifera (55 µm x 4 µm). Second: Gomphonema insigne (57 µm x 11 µm). Top: Tryblionella levidensis (30 µm x 15 µm). Bottom: Cyclotella meneghiniana (12 µm x 12 µm). Image: Joe Holmes, © Canadian Museum of Nature.

Back at the lab in the museum’s collections facility, samples were processed, and specimens photographed and identified using an online Italian government diatom guide. Interestingly, the diatoms reveal a lot about Italian water quality and terrain at the sampled sites.

The Aquarium pond in the Orto Botanico di Palermo, Palermo, Sicily. Left: Navicula radiosa (70 µm x 10 µm). Top: Pseudostaurosira brevistriata (30 µm x 15 µm). Middle: Cocconeis placentula (22 µm x 14 µm). Bottom: Rhoicosphenia abbreviata (32 µm x 9 µm). Image: Joe Holmes © Canadian Museum of Nature.

For example, most diatoms at sample sites indicate a preference for alkaline pH reflective of the limestone, volcanic and carbonate rocks that make up most of the Italian Peninsula. Some species are indicators of water with moderate to high levels of organic nutrients, likely from nearby farms. Lastly, some specimens indicate traces of brackish water, perhaps due to salt in the Italian soil or proximity to the Mediterranean Sea.

Girgenti River Estuary, San Leone, Sicily. This is tidal water, with the Mediterranean Sea at left, so all the collected diatoms are marine species. Top: Achnanthes brevipes (27 µm x 8 µm) Second: Navicula ramosissima (43 µm x 7 µm) Third: Navicula longa var irregularis (48 µm x 9 µm) Bottom: Synedra fasciculata (31 µm x 6 µm). Image: Joe Holmes © Canadian Museum of Nature.

The trip yielded many of the same species of diatoms I’ve collected in Canada, Ireland and the Middle East.

Torrente Santa Venera, Giardini Naxos, Sicily, looking southeast toward the Ionian Sea. Top: Nitzschia sigma (61 µm x 7 µm). Second: Nitzschia communis (29 µm x 4 µm). Third: Nitzschia recta (69 µm x 7 µm). Bottom: Navicula apiculata (34 µm x 9 µm). Image: Joe Holmes © Canadian Museum of Nature.

For museum diatom researchers and students these new Italian specimens are proof that some scientific souvenirs can provide a lot more than just good memories!

Vigna di Valle, Bracciano Lake, the source of Rome’s water. The collected diatoms indicate that the water is relatively clean, with low nutrient levels. Top: Aneumastus tuscula (32 µm x 12 µm). Bottom-Left: Cocconeis neodiminuta (21 µm x 13 µm).  Middle: Raphoneis surirella (30 µm x 8 µm). Right: Cavinula pseudoscutiformis (12 µm x 9 µm). Image: Joe Holmes © Canadian Museum of Nature.

 

 

 

 

 

 

 

Women in Science: What’s Your Impression?

What percentage of 24-to-35-year-old Canadian women have a university degree in the following programs: Science, Technology, Engineering, Mathematics and Computer Science (STEM)?

That’s one of the questions we asked Museum visitors earlier this year at a Science by Night event in anticipation of the Museum’s exciting new exhibition Courage and Passion: Canadian Women in Natural Sciences which opened in July. (Keep reading for the answer!)

At Science by Night, several female colleagues in the Palaeobiology section of the Museum – myself included – featured a Women in Science kiosk, a mini-version of the current exhibition, where we profiled inspiring, trailblazing female Canadian researchers, including Alice Wilson, Madeleine Fritz and Francis Wagner. Some of the interesting facts we shared are profiled in the images and captions below.

Alice Wilson (1881-1964) was the first female geologist employed by the Geological Survey of Canada, hired in 1909. Despite the many barriers of being a woman in science in the early 1900s, Wilson persisted and became the first woman elected as a Fellow of the Royal Society of Canada. Image: Natural Resources Canada photo number 112040. Licensed under the Open Government Licence – Canada

Madeleine Fritz (1896-1990) studied at McGill and the University of Toronto and became the Associate Director of Palaeontology at the Royal Ontario Museum. She was a leader in the study of Ordovician bryozoa (ancient, aquatic moss-like organisms) in North America, paving the way for many female scientists after her. Image: Courtesy of the Royal Ontario Museum.

Frances Wagner (1927-2016) was the first woman to work extensively in the field alongside male colleagues collecting mineral core samples in Ontario, Quebec, Nova Scotia, the Northwest Territories and the Arctic Islands. She was a pioneer in micropaleontology, the study of microscopic fossils, and led this discipline when it was a breakthrough field. Image: Courtesy Fisheries and Oceans Canada.

We also wondered: how do museum visitors perceive the role of women in scientific fields today?

To find an answer and to spark discussion we asked visitors questions, including to estimate the percentages of young Canadian women today with a university degree in the following programs: Science, Technology, Engineering, Mathematics and Computer Science (STEM).

 Although our paper-and-pencil survey may not be a scientifically valid study, the results were definitely interesting. In general, participants thought that the number of young women with a degree in a science-related university program is lower than is actually the case. Interestingly, the average responses from male and female participants were almost identical.

For example, on average, participants guessed that women comprise 38-percent of degree holders in science and technology programs. However, based on 2011 Statistics Canada data on degree holders among 25-to-34-year-old, women hold 59-percent of these science-related degrees.

Participants’ estimates for mathematics and computer science were closer, with participants guessing that women hold 25-percent of these degrees, while the actual number is 30-percent. Only for engineering were participants’ estimates very close to reality, with participants’ guessing 24-percent and while the Statistics Canada data reveal that it’s 23-percent.

At the Women in Science kiosk at the Museum’s Science by Night event the wall was lined with Post-it notes with participants’ responses to the question: “Why is it important to have all genders equally represented in the field of science?” Most of the responses touched upon the idea that it is especially important to have equal representation to maximize scientific innovation, creativity, and competitiveness. Image: Marisa Gilbert, © Canadian Museum of Nature.

A number of possible interpretations could be made from these results, but I think it serves to highlight the accurate perception that the study of science remains male-dominated in universities. Men still do have greater representation in the field of science, and this has been the case historically for all the sciences.

But the situation is slowly changing. Based on the 2017 NSERC Women in Science and Engineering Summary, from 1992 to 2014 the number of women earning a Bachelor’s degree in natural sciences and engineering in Canada, as a percentage of all students, increased by 7.1-percent (from 31.6 to 38.7 percent). The increase for women achieving a Master’s science-related degree was 8.5-percent (from 27.4 to 35.9-percent) and at the Doctoral level the number of women earning science-related Ph.D.’s increased 11.1-percent (from 20.2 to 31.3-percent) in that 22-year period.

At the Women in Science kiosk at the Museum’s Science by Night event children got involved by drawing what they think a scientist looks like. A five-year-old boy drew this picture of a scientist holding a microscope and a magnifying glass.

Though these may seem like small changes, they are positive ones. My hope is that by continuing to highlight these changes and by celebrating admirable and inspiring historical female scientists, who often don’t receive enough recognition, we can help prompt more girls and young women to enter the exciting world of science!

Living on the edge: the voles of Svalbard

In northern Norway, on an island well within the Arctic Ocean, there is a very special population of voles.

These small rodents live on Spitsbergen, the main island of the Svalbard archipelago. They were introduced between 1920 and 1960, possibly from Russian mining-supply ships.

The species was first identified as the field vole (Microtus agrestis) found throughout Europe and Russia. However, genetic analysis and a recent taxonomic update have identified this species as the sibling vole (Microtus levis) which lives mainly in eastern Europe and western Russia.

A sibling vole (Microtus levis). Image: Dominique Fauteux © Canadian Museum of Nature.

Although they are not a species native to the Arctic, these voles have still found a suitable site to settle and thrive in a unique way.

The abandoned settlement of Grumant, on the island of Spitzberg in Svalbard. You can see much more green vegetation under the cliff that is occupied by a colony of Thick-billed Murres. Image: Dominique Fauteux © Canadian Museum of Nature.

In the region of Grumant, a former Russian mining settlement, there is a cliff where hundreds of Thick-billed Murres breed each year. The droppings produced by this colony of seabirds have progressively flowed down the cliff for hundreds of years or more, greatly enriching the soil below. Where the slope is softer, nutrient-rich soil allows the growth of a very rich flora. These grasses are an important source of food for voles when they come out of their burrows found in the nearby rocky outcrops.

Despite low predation because of their recent introduction, the vole population fluctuates irregularly and dramatically from about 200 voles per hectare to an almost total absence of voles.

Researchers from the University of Tromsø – The Arctic University of Norway and the Canadian Museum of Nature are working together to try to explain these fluctuations. Various hypotheses have been studied.

Early observations suggest that competition is so fierce during periods of high abundance that the resulting social effects (fighting, stress, changes in reproductive behaviour, etc.) reduce the survival and reproduction of voles. In addition, some voles do not reach maturity during periods of high density, which hinders the reproduction of the population. Finally, during two winters when ice crusts formed on the ground, the populations were almost decimated. This shows the importance of meteorological factors on the population dynamics of voles on Spitsbergen.

Arctic foxes prowl near the recently-introduced voles, but the foxes are unaccustomed to hunting them. Image: Dominique Fauteux © Canadian Museum of Nature.

Spitsbergen is inhabited by nearly 3000 people. Its economic past included whaling, hunting fur animals and coal mining.

Although located in the High Arctic, the island is affected by the North Atlantic Drift, a marine current originating from the Gulf Stream. The average temperature of Spitsbergen varies between –14° C in winter and 6° C in summer. There is a rich fauna including a few thousand polar bears, a reindeer subspecies, thousands of Dovekies, Thick-billed Murres, and many other seabirds. Because of this rich biodiversity, two-thirds of the island is now protected and Spitsbergen is now a very popular tourist destination.

(Translated from French)

Botanist reveals his favourite grass

When I tell people that I study grasses, the first response I get is generally a wisecrack about the “grass” people smoke.

After a laugh, I explain that it’s not that kind of grass, and that grasses are about more than pretty lawns: humanity relies on grasses for our survival. Indeed, civilization arose in concert with the domestication of grasses, including wheat, rice and corn.

And, there’s still a lot to learn about the grass family (Poaceae), which includes about 11,000 species, of which only about ten have been domesticated for human consumption.

Museum researcher Jeff Saarela, Ph.D. collecting grasses along the banks of the Coppermine River near Kugluktuk, Nunavut. Image: Paul Sokoloff, © Canadian Museum of Nature.

The next question I often get is “What’s your favourite grass?”

That’s a tough one. I find all species unique and interesting in their own ways, so I have a different favourite at different times. My current favourite grass species is the Arctic Brome Grass (Bromus pumpellianus).

This species is at the intersection of my research program’s two major themes. The first is the global systematics of grasses: characterizing grass biodiversity and evolutionary history.

The second theme focuses specifically on the biodiversity of Arctic vascular plants. Grasses are one of the most diverse and widespread groups of Arctic plants, with some species growing as far north as Canada’s northernmost point of land near Cape Columbia, Nunavut.

The Arctic Brome Grass (Bromus pumpellianus) is museum researcher Jeff Saarela’s current favourite grass. Image: Paul Sokoloff, © Canadian Museum of Nature.

Arctic Brome Grass (Bromus pumpellianus) is part of a worldwide genus (Bromus) of about 160 species. This genus is interesting because it’s closely related to the group of grasses that includes wheat (Triticum aestivum) and other cereals. My goal is to use DNA to better understand the origin of this genus, how its various species are related to one other (and how they evolved), and how they came to live where we can find them now.

Arctic Brome Grass is the only native North American member of a primarily Eurasian group of closely-related species within Bromus. It occurs in western Canada, and its range extends beyond the treeline into the southern Arctic, as far north as the Arctic coast, and as far west as Bathurst Inlet, Nunavut. As the climate changes, this grass may migrate northwards to adjacent Victoria Island.

Check out the video to learn more.

This herbarium specimen of Arctic Brome Grass (Bromus pumpellianus) is one of thousands that museum researcher Jeff Saarela has examined for his research on the biodiversity of Arctic grasses. Catalogue number: CAN 595172. Image: Shan Leung © Canadian Museum of Nature.

What’s your favorite grass? (No wisecrack responses, please.)

 

Museum birds tell their tale

What can you learn from a bird of paradise collected in the middle of the last century? Or a nest dating back to 1925? In fact many things, not only about the specimen itself but also about its environment.

New techniques, such as analysis of DNA preserved in specimens, can also provide information that would have been inconceivable at the time they were collected.

The five specimens below provide a glimpse into the wealth of ornithological information contained in museum collections.

An alien bird? Following the custom of his people, the indigenous hunter from New Guinea who collected this Magnificent Bird-of-paradise in the middle of the last century cut off the bird’s feet, giving the bird this strange appearance. Collection number: CMNAV 83536. Image: Michel Gosselin © Canadian Museum of Nature.

The Magnificent Bird-of-paradise (Diphyllodes magnificus) is a bird of New Guinea. This specimen was collected in 1957 by George Holland (1911-1985), a Canadian entomologist who was studying parasites of birds in New Guinea. The specimen was given to him by an indigenous trapper for whom bird hunting was an ancestral practice.

According to their custom, indigenous people from the island always removed the feet of birds they capture. Labels are therefore attached to the head rather than the bird’s feet, as would normally be the case with museum specimens. As the first specimens brought to Europe in the 16^th century were also without feet, naturalists at the time believed these birds didn’t have any. They were therefore named “birds of paradise”, under the assumption that they spent their entire life flying in the sky.

A relic from the past: this bird’s nest dating back to 1925 is made of mop strands and horsehair. It is covered in coal dust. Image: Michel Gosselin © Canadian Museum of Nature.

This Baltimore Oriole (Icterus galbula) nest was collected in Ottawa in early April 1926 by George R. White (1856-1927), a well-known naturalist from Ottawa’s Lowertown. As orioles do not come back from their wintering grounds until May, this nest dates back to the previous year.

Note that the nest is made exclusively of mop strands and a little horsehair, instead of plant fibres as is usually the case. What’s more, the mop strands are completely blackened by coal dust. This simple bird’s nest therefore reflects what Ottawa was like at the time: the omnipresence of coal, for heating, but also the locomotives of the railways that served downtown Ottawa, and the widespread presence of horses as a means of transportation.

Why are these eggs all so different? Image: Michel Gosselin © Canadian Museum of Nature.

These Ring-billed Gull (Larus delawarensis) eggs all come from the same colony. They were collected in 1994 at the Québec City harbour by officers of the Canadian Wildlife Service, as part of a program to control gull populations.

Eggs of birds that nest on the ground, such as gulls, generally have a colouring that serves as camouflage. Moreover, among species that live in colonies, where birds lay eggs very close to one another, eggs often differ quite a bit from one female to another. This certainly helps females identify their nests.

The differences between individuals, as demonstrated by these museum specimens, are an important facet of biodiversity.

Witness to a lost population: this specimen captured in 1879 belonged to the original population of Wild Turkeys in Canada. Collection number: CMNAV 6431. Image: Martin Lipman © Canadian Museum of Nature.

This Wild Turkey (Meleagris gallopavo) specimen was captured by a hunter in 1879 in Essex County (southernmost tip of Ontario). It was later acquired by Toronto ornithologist J. Henry Fleming (1872-1940) who donated it in 1913 to the Geological Survey of Canada Museum, the forerunner of the Canadian Museum of Nature.

This specimen belongs to the original population of Wild Turkeys in Canada, which were extirpated in 1907 due to uncontrolled hunting. The range of this original population did not extend further east than Toronto.

In 1984, Wild Turkeys from neighbouring U.S. states were reintroduced into Ontario by the Ministry of Natural Resources, first in southern Ontario, then gradually further and further north. Today, the species is widespread up to Algonquin Park and throughout Southern Québec.

Conditions have changed significantly since the days when this turkey was alive: hunting is now much more controlled and Wild Turkeys now frequent agricultural lands where corn residues provide a substantial source of food.

A museum preserves more than just specimens, as witnessed by these notes about the Whooping Crane dating back to 1894. Image: Michel Gosselin © Canadian Museum of Nature.

The Whooping Crane (Grus americana) is a now an endangered species, but was once less rare.

The notes in the above photograph date back to 1894 and were made by the young Rudolph M. Anderson (1876-1961), then aged 18. He relates the nesting behaviour of the Whooping Crane in Madison, Iowa, where he was living at the time. Breeding birds disappeared from the United States in 1939 but have been recently reintroduced.

Anderson was the Head of the Biology Division of the National Museum of Canada (now the Canadian Museum of Nature) from 1920 to 1946. He took many notes over the course of his career; they are now part of the Museum’s scientific archives. Like specimens, the Museum’s archival records reflect changes in the environment over the last century and a half.

Translated from French.

Ottawa lazurite find points to undiscovered Canadian deposit

This deep blue lazurite specimen from the Canadian Museum of Nature’s mineral collection glimmers with part mystery and part inspiration. First, the mystery.

Half of a baseball-sized lazurite specimen found in surburban Ottawa in 1992. This unusual discovery has led museum mineralogists to believe there’s a significant undiscovered lazurite deposit somewhere in Ontario or Quebec. Collection number CMNMC 84465. Image: Michael J. Bainbridge, © Michael J. Bainbridge.

This lazurite sample is half of a baseball-sized cobblestone found amid landscaping stones near the entrance of the Ottawa General Hospital by keen-eyed Ottawa resident Judith Bainbridge in 1992.

Luckily, Mrs. Bainbridge and her family are rock hounds and members of the Ottawa Valley Mineral Association. So, when she spotted this unusual bluish rock among the ordinary landscaping stones she broke the specimen in half and brought it to the museum staff for formal identification.

To her surprise, and ours, we identified the blue mineral as lazurite, better known as lapis lazuli, a prized mineral for jewellery making when found in its deep, rich-blue form.

We were astonished that such a high quality lazurite specimen was found in Ottawa. Lazurite is found worldwide as crystals and massive veins, with the best-known localities in Siberia, Russia, Colorado and California USA, and localities in Afghanistan, Myanmar, and Chile.

This beautiful blue bird is carved from Afghani lazurite. Collection number: CMNGE 22120. Image: Michael J. Bainbridge, © Michael J. Bainbridge.

But the only known Canadian deposits are two sites along the Soper River, near Kimmirut on the southern tip of Baffin Island, Nunavut. However, unlike Mrs. Bainbridge’s rich blue-coloured lazurite, the Soper River lazurite is usually pale blue or even green.

If Mrs. Bainbridge’s lazurite wasn’t from Soper River, where was it from? The landscaping stones at the Ottawa General Hospital that included the lazurite were from several local sand and gravel pits. My colleagues and I searched the gravel pits for more lazurite specimens, but it proved to be harder than finding a needle in a haystack given that each site had millions and millions of ordinary stones, most of them still buried in glacial deposits. We didn’t find more lazurite.

Nonetheless, we concluded that our lazurite specimen had likely been transported by glaciers from an unknown deposit somewhere in Ontario or Quebec where lies a well-hidden, rich vein of lazurite!

Cover of Michael Bainbridge’s forthcoming book. Image: Michael Bainbridge, © Michael Bainbridge

While the Ottawa lazurite’s definitive source is still a mystery, it’s had a clear impact. It helped inspire one of Canada’s leading professional mineral photographers, Mrs. Bainbridge’s son, Michael Bainbridge, just 12-years old when the lazurite mystery began.

Many of his beautiful mineral photographs are in the museum’s Earth Gallery, and his upcoming book The Pinch Collection at the Canadian Museum of Nature will be published later this year.

All of which shows that you never know what will be revealed by an interesting mineral find.

Museum’s millions-strong Arctic marine invertebrates collection gets digitized

The Arctic is undergoing more extreme climate-related changes and at a faster rate than any other region on Earth. In order to understand the nature and impact of these changes, it’s critical that we document Arctic biodiversity, including the amazing diversity of marine invertebrates, from anemones to amphipods.

To aid this effort, the Canadian Museum of Nature has launched an Arctic collections digitization project. We’re digitizing the collections information for the museum’s several million Arctic invertebrate specimens and are in the process of putting the information online for researchers worldwide.

Commonly known as the Sea Angel, Clione limacina is a pelagic, or free-floating, marine sea slug. Contrary to its name, it’s a voracious predator that feeds almost exclusively on a pelagic sea snail species. Image: Samantha Brooksbank, © Canadian Museum of Nature.

The museum’s Arctic marine invertebrate collection consists of thousands of species of crustaceans, bivalves, bristle worms, anemones, sponges, and many other taxonomic groups. The specimens were collected over the past century by generations of museum researchers and also donated to the museum, including from the former Arctic Biological Station that was part of Fisheries and Oceans Canada.

Given their great diversity and widespread distribution Arctic marine invertebrates are a “canary in the coal mine” of environmental change. For example, when the ocean warms many species will be able to move farther north. Some will be looking for cooler temperatures while others will be pushed out due to competition for food and territory.

In order to identify these potential changes it’s necessary to have easy access to historical baseline species data—exactly what our Arctic collections digitization project will provide.

Hyperia galba is a small amphipod distinguished when alive by its large green eyes. In preserved specimens (shown here) the eye colour fades. These amphipods live within sea jellies, sharing the sea jelly’s food and feeding on its eggs. Image: Samantha Brooksbank, © Canadian Museum of Nature.

When a specimen is collected, the researcher creates an identification label that records vital scientific information including where, when, and by whom the specimen was collected, and eventually, who identified it. Similarly, collections staff gather any supplementary information provided by the collector, and link this to the specimen.

Through the Arctic collections digitization project, all of the specimen information for millions of Arctic invertebrates will be digitized in a searchable database and made publicly available.

Large numbers of the amphipod Themisto libellula live in the Arctic’s cold waters and are food for many species of fish, seabirds and marine mammals. Image: Samantha Brooksbank, © Canadian Museum of Nature.

The Arctic collections digitization project is possible due to a $4-million donation to the museum by the Beaty family.

This generous gift is turning the museum’s Arctic invertebrate collection into a powerful online force for both public education and scientific research on the Arctic and the multiple stressors affecting this beautiful yet fragile ecosystem.

 

Is the world’s largest Triceratops skull sitting in our collection?

On June 6th, 1929, renowned fossil collector Charles M. Sternberg sat writing in his journal in a Saskatchewan field camp recording the first day of his team’s summer fossil prospecting. He noted the work done, the area’s rock formations and the fossil specimens collected.

Of particular note was the first dinosaur fossil found, the partial skull of an exceptionally large Triceratops prorsus.

Referring to the bony frill around this horned dinosaur’s neck, Sternberg finished the journal entry dramatically: “This is the largest crest I have seen.”

In this 1901 painting by Charles R. Knight depicting a lone Triceratops, the broad, bony shield that projected around the dinosaur’s neck is especially prominent. The body shape and pose reflect the early 20th-century view of dinosaurs as lumbering animals that dragged their tails. Image: Charles R. Knight, public domain.

Charles Sternberg took this photograph of the Triceratops skull in the field. The two projections on the lower right are the brow horns. Today, most of the specimen is still covered in a layer of rock. Catalogue number: CMNFV 56508. Image: C. M. Sternberg, © Canadian Museum of Nature.

Fast-forward to 2015 and Canadian Museum of Nature dinosaur palaeontologist Jordan Mallon was reading Sternberg’s field journals.

Sternberg’s big crest comment caught his eye—and his imagination. Could this possibly be the largest Triceratops ever collected? What made the possibility particularly exciting is that the answer lay a hundred meters away in the museum’s collection.

The specimen still lay wrapped in the protective layers of plaster applied to it in 1929. Dr. Mallon proposed we prepare the specimen and put Sternberg’s observation to the test.

This is where I enter the story. I am the coordinator of our fossil preparation program, and so it’s now my job to ready the fossil for scientific examination by opening the plaster field jackets and preparing the fossil.

This will not be an easy task.

The skull is so large that when it was collected it was wrapped in two separate plaster field jackets. The larger, a 650-kg section, includes two thirds of the frill, the top of the dinosaur’s cranium, and the two long brow horns. A smaller, 400-kg section contains the remaining third of the Triceratops‘ frill.

The two field jackets containing Charles M. Sternberg’s 1929 Triceratops prorsus specimen. The two brow horns are discernible in the shape of the larger jacket (left), against which is a board showing illustrations of this dinosaur’s skull. The smaller jacket (right) is shown following initial preparation of one side. Catalogue number: CMNFV 56508. Image: Alan McDonald, © Canadian Museum of Nature.

Preparing any fossil comes with its own challenges, but the preparation of the Triceratops skull will be especially difficult.

While completely wrapped in its field jacket, the larger portion of the skull is safely supported on all sides. However, we know that given the massive size and weight of the skull, the jacket might give way during opening if not properly supported from the exterior, and the skull could tear itself apart.

So, we decided to begin by opening the section containing the smaller portion of the frill. This is permitting us to assess the fossil’s overall condition and stability, informing our course of action for safely opening the larger field jacket.

The smaller field jacket following the first round of plaster removal. The fossil frill is beginning to peek through in two places. Catalogue number: CMNFV 56508. Image: Alan McDonald, © Canadian Museum of Nature.

Now, five months into the project, progress has been slow but steady.

There is a layer of thick stone covering the fossil, and we’ve discovered that the majority of the underside of the frill is fractured but repairable.

With hard work, a lot of adhesive, and a little luck, we’ll know more in the upcoming months, and one day hope to add an exciting footnote to Charles M. Sternberg’s old journal entry.

Stay tuned for an update!

With one side of the plaster jacket completely removed, the frill is now completely exposed. The fossil’s heavily cracked surface was treated with a consolidant solution to strengthen it, but repair of the major breaks awaits. Catalogue number: CMNFV 56508. Image: Alan McDonald, © Canadian Museum of Nature.

Biting into the Past

If you’re a mammal – and I suspect you are – your teeth are arguably the most important part of your body, at least to a palaeontologist like me.

You see, teeth are the hardest tissues in the body, and as a result often the only record we have of extinct mammals. Luckily, we can use mammal teeth to identify the species to which they belong.

Fossil teeth also provide a wealth of biological information that we can use to understand things about extinct mammals that we otherwise can’t observe (at least not without a time machine).

We start with what we’ve learned from studying the teeth of living mammals.

Mammals, of course, have a variety of diets. As a simple example, tigers eat deer, while horses eat grass. Mammal teeth thus come in a variety of characteristic shapes because they provide a variety of functions, including pulverizing, slicing, and grinding.

A) The varied shapes of the upper dentition (right) of a honey badger’s teeth (Mellivora capensis) reflect its generalist diet (Catalogue number USNM 175751); (B) The fairly uniform teeth (left) of a modern beaver (Castor canadensis) are similar to its extinct Pleistocene relative (right) indicating that this ancient animal also had an herbivorous diet. (Catalogue number: CMNFV 16407); (C) The robust, peg-like teeth (right) of the herbivorous Megalonyx jeffersoni, a Pleistocene giant ground sloth (left), enabled it to crush a diet of leaves, twigs, and perhaps also nuts (Catalogue number CMNFV 31778). Images: A) Left: public domain; Right: Danielle Fraser, © Canadian Museum of Nature. B) Left: © Steve Hersey (CC BY-SA 2.0); Right: Danielle Fraser, © Canadian Museum of Nature. C) Left: public domain; Right: Danielle Fraser, © Canadian Museum of Nature.

The fact that mammal teeth have characteristic shapes related to their function is lucky for palaeontologists because it enables us to immediately understand some very basic things about the biology of extinct mammals from their teeth, for example whether an ancient animal was an herbivore or carnivore.

However, it’s not always so clear cut.

The polar bear (Ursus maritimus) and raccoon (Procyon lotor) have very similar teeth but very different diets. Polar bears eat seals while raccoons are omnivores. So, how do we distinguish between species with relatively similar chompers?

Colourized, 3D surface scans of a polar bear tooth (lower left, first molar) and a raccoon tooth (lower right, first molar). Both teeth show a similar basic topography of peaks and valleys. These specimens are part of the collections of the Finnish Museum of Natural History. Scan data provided by Dr. Alistair Evans and Dr. Silvia Pineda-Munoz. Catalogue numbers HELU201 (polar bear) and HEL885 (raccoon). Image: Danielle Fraser, © Canadian Museum of Nature.

One way is to use high-tech, 3D imaging methods that enable us to identify minute differences in tooth shape that correspond to seal skewering, or in the case of urban raccoons, a diet of garbage.

This video shows a 3D rotating micro-CT scan of the right lower first molar of Parictis parvus, an early bear that lived around 38 million years ago. Scans such as these permit a detailed examination of the three-dimensional shape of fossil teeth. This specimen comes from the late Eocene Calf Creek Fauna of the Cypress Hills in Saskatchewan and is housed at the Royal Saskatchewan Museum. The scan data was captured at Carleton University by Dr. Fred Gaidies of the Department of Earth Sciences. Catalogue number RSM P661.1701. Image: Danielle Fraser, © Canadian Museum of Nature.

Teeth also record the chemical composition of what an animal eats and drinks during its life.

The chemical formula for water is H₂O; a molecule of water has two hydrogen atoms and one oxygen atom. But natural water actually comes in a range of different isotopic varieties. (An isotope is a natural variant of an element, such as oxygen, with an identical number of protons, but varying numbers of neutrons). The ratio of different oxygen isotopes in a body of water depends on many factors, including the water’s temperature and salinity. Thus, water from different sources, such as lakes, rivers or wetlands, have slightly different oxygen isotope compositions.

While teeth are growing, whenever an animal drinks water these oxygen isotope differences are incorporated into its tooth enamel. As a result, we can take samples of tooth enamel and learn a lot about what, and even where, an animal drank.

The parallel rows visible on the pronghorn (Antilocapra americana) molar (left) are areas where enamel was removed for oxygen isotope sampling. Blog author Danielle Fraser (right) samples a fossil tooth using a Dremel tool. Images: Danielle Fraser, © Canadian Museum of Nature (left), Marisa Gilbert, © Canadian Museum of Nature (right).

I hope that with this blog post I’ve given you something to chew on and convinced you that fossil mammal teeth are a lot more exciting than they initially sound — they certainly always give me a big smile when I find them!