Carnegie Museum of Natural History

One of the Four Carnegie Museums of Pittsburgh

paleontology

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March Mammal Madness Update

sabertooth cat fossil on black background with yellow dandelions

It’s time to break out the big cats.

Last night’s matches pitted various “cats” against each other, although some cats were only cats in name (for example, the catfish and antlion).

Our most anticipated match had a nimravid (a fossil false sabertooth cat) versus a dandelion. We weren’t sure if the nimravid would only be fossilized bones and stand little chance against the dandelion, or if the nimravid would come to life and be allergic to dandelions. So when the contest began, the nimravid was alive but it began sneezing and as a by-product bit down decapitating the fearsome dandelion. If you fancy seeing a real nimravid, there is one on display in Cenozoic Hall at the Carnegie Museum of Natural History.

For more details on this year’s tournament, click here.

Blog post courtesy of the Section of Mammals. 

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“Amazing, just like a dinosaur!”

Exclamations like this are common among bird biologists, especially when face-to-face with a Pileated Woodpecker or a ferocious Chickadee. Decades of Jurassic Park films have caught us in a tautological trap where birds remind us of dinosaurs—because Hollywood models dinosaurs on birds. From the coordinated flock movements of chickens foraging to the reptilian eyes of a Heron, I often catch myself wanting to say, “Amazing, just like a dinosaur!” But, I restrain myself because my source is mostly Stephen Spielberg.

At the Carnegie Museum of Natural History something that makes the Section of Birds special is its proximity to a world-class collection of dinosaur fossils and the paleontologists they attract. PhD students, like Sam Gutherz from Ohio University, use our collections to study the pulmonary tissue and skeleton of birds to address questions regarding the evolution of the respiratory system in a range of archosaurs.

three people working at desks
Sam Gutherz and colleagues from Ohio University measure bird skeletons at the Carnegie Museum of Natural History to better understand the biology of dinosaurs.

Sam visits natural history museums for both the birds and the dinosaurs—systematically measuring bones and testing questions that ultimately support or refute the connection between birds and dinosaurs. Decades of work by scientists like Sam and his colleagues have built a case using multiple lines of evidence that birds evolved from dinosaurs. In fact, paleontologists have been so successful that bird biologists and Hollywood producers stand on their shoulders.

Chase Mendenhall is Assistant Curator of Birds, Ecology, and Conservation at Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

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Eorubeta: A Mysterious Ancient Frog Revealed

By Amy Henrici

I recently completed a project on fossil frogs from east central Nevada that my collaborators and I identified as the enigmatic Eorubeta nevadensis Hecht, a species that was originally based on a single, poorly preserved specimen that had been discovered in a well core.

The new collection of Eorubeta came from the Sheep Pass Canyon area about 12.5 miles northeast of the well core site. Peter Druschke discovered fossil frogs here in 2005 while working on his PhD dissertation on a rock unit known as the Sheep Pass Formation. Peter and fellow University of Nevada Las Vegas graduate students Josh Bonde and Aubrey Shirk and colleagues Dick Hilton and Tina Campbell (of Sierra College in Rocklin, California) collected additional fossil frogs in subsequent years. I was very fortunate to be invited to join the team, and we collected over 60 specimens for Carnegie Museum of Natural History in 2012, 2013, and 2016.

ancient frog fossils
Part (A) and counterpart (B) of the first-known specimen of the fossil frog Eorubeta nevadensis. This specimen resides in the Vertebrate Paleontology collection of the American Museum of Natural History in New York.

The field site lies in the South Egan Range Wilderness Area of east central Nevada. Being a wilderness area, we could only drive on existing roads, and had to hike nearly a mile to the fossil-producing slopes. The climate in Nevada is challenging to work and camp in, with temperatures reaching over 100 degrees Fahrenheit during the July 2013 field season and nighttime temperatures dipping into the high 20s during the November 2016 season.

White Pine County, Nevada.
Road into the South Egan Range Wilderness area, White Pine County, Nevada. The area burned three months prior to the 2012 field season. The fire cleared vegetation from the fossil-producing slopes, making it easier to find fossils, though burnt tree branches left us streaked with charcoal.

When Eorubeta was originally named, the rock unit from which this frog came (Member B of the Sheep Pass Formation) was thought to date to a time interval known as the Early Eocene (56–47.8 million years ago). More recently, however, Peter has determined that this unit was probably latest Cretaceous–Paleocene (72.1–56 million years ago) in age instead. It is thus possible that Eorubeta spanned the Cretaceous–Paleogene boundary (66 million years ago) and survived the infamous asteroid impact that caused the extinction of non-avian dinosaurs and many other animal and plant species.

ancient frog fossil

ancient frog fossil
Two of the recently-collected specimens of Eorubeta nevadensis.

Peter determined that the beds in which the fossil frogs were preserved were part of a very high-elevation lake system (1.4–2.2 miles in elevation), similar in this way to today’s Lake Titicaca located in the Andes Mountains on the border of Bolivia and Peru. To date, Eorubeta is the only fossil frog known to have inhabited such a high-elevation environment. Most fossil frogs from this time come from prehistoric river and lake systems situated on coastal plains. The discovery of Eorubeta suggests that ancient frogs probably inhabited a greater variety of environments than the current fossil frog record indicates.

The first specimen discovered by Peter in 2005 indicates that Eorubeta may have reached a considerable size, though the fossil’s extremely weathered condition makes its identification uncertain. An analysis of the relationships of Eorubeta to other frogs reveals that it is more archaic than spadefoot toads, Neobatrachia (a group known as modern frogs), and their relatives.

ancient frog specimen
The largest known specimen of Eorubeta.

Peter Druschke, the team geologist who discovered the specimen.
Peter Druschke, the team geologist who discovered the specimen.

To learn more about Eorubeta, please follow this link to our paper recently published online in the Journal of Vertebrate Paleontology: https://www.tandfonline.com/doi/full/10.1080/02724634.2018.1510413.

Amy Henrici is the collection manager for the Section of Vertebrate Paleontology at Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

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Meet The Newest Addition To The Fossil Vertebrate Collection

by Amy Henrici

mammoth tooth from the side
The new mammoth tooth as viewed from the side. The crown, or exposed part, of the tooth is at the top, and the root is at the bottom.

The Section of Vertebrate Paleontology at Carnegie Museum of Natural History acquires fossils in a variety of ways, most commonly through field work by Section staff, exchanges with other museums, donations, or (very rarely) purchases. The most recent addition to the collection came by way of a donation.

Gary Kirsch discovered the tooth shown above in a sand-gravel bar of a central Ohio stream in 1988 while collecting sediment samples. He had set his sampling equipment on the sand-gravel bar and was moving between the bar and the stream collecting samples. During one of his many forays, Gary noticed an edge of the tooth sticking out of the bar and pulled it out. It was covered in mud, which he quickly cleaned off in the stream to reveal the beautifully preserved tooth, which he identified as that of a mammoth.

Gary recently emailed photographs of the tooth to Assistant Curator of Vertebrate Paleontology Matt Lamanna because he wanted to donate it to the museum. Acceptance of his generous offer required some research: mammoth and Asian elephant teeth are very similar, and because none of the Section staff are experts in fossils of Pleistocene (Ice Age) mammals, we reached out to Pleistocene expert Blaine Schubert at East Tennessee State University, who often uses our collection, to verify Gary’s identification. Blaine was certain that it was a mammoth tooth because an Asian elephant tooth could only have come from a zoo or circus animal, which was highly unlikely. Blaine was curious about how teeth of the two species are distinguished, so he forwarded the photographs to an elephant expert at his university, Chris Widga.

mammoth tooth from the top
The grinding (i.e., lower, occlusal) surface of the tooth, showing the fairly crenulated tooth enamel.

Chris determined that the tooth is the first (forward-most) molar from the left upper jaw, and because it has fairly crenulated enamel, that it is from a woolly mammoth (Mammuthus primigenius). Through comparison with tooth eruption and wear schedules (sequences) of modern elephants, Chris concluded that the animal was in its late teens to early 20s when it died. In the wild, modern elephants generally live to about their mid-50s, so this single specimen offers a window into mammoth mid-life.

The Section is grateful to Gary for his thoughtful donation. The specimen will be put on temporary display soon in the PaleoLab window on the first floor of the museum for public viewing.

Amy Henrici is the collection manager for the Section of Vertebrate Paleontology at Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

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Badwater 20: Not So Bad After All

by Lauren Raysich

small fossil

Although many people are familiar with fossilized bones of dinosaurs and other large extinct creatures, some fossils can be so small that a microscope is needed to see them. In Carnegie Museum of Natural History’s PaleoLab, volunteers like me use microscope stations to search for tiny fossils in different sediments collected from sites all over the world. Sediment from the Badwater 20 locality in Wyoming interests me more than any other. Sediment from this site dates to a time known as the Eocene Epoch. The middle of three epochs in the Paleogene Period, the Eocene lasted from 56 to 33.9 million years ago. Many fossils found from the Eocene belong to some of the oldest known members of modern mammal groups. Studying these fossils helps scientists trace the evolutionary histories of mammals we know today.

After searching through the Badwater 20 sediment for nearly two weeks, I had found only fragments of bones and teeth. Then, surprisingly, I came across a small, complete bone. It is not common to find complete fossil bones that are this tiny because they can be broken easily, whether by erosion or by being crushed by scavenging animals or water currents. Fossils are not immune to human-induced hazards either. After I found the bone, I was so excited that I accidentally dropped it on the floor of the lab and had to use a magnifying glass to relocate it! (Thankfully, it didn’t break.)

small fossil next to a penny for scale

This bone interested me more than any other because it was the first bone I’d found from the Badwater 20 site that wasn’t fractured in some way. Since the bone is so small, I figured it had to have come from a tiny mammal. Through research and the help of other museum volunteers and staff, I have concluded that this bone is a phalanx (finger or toe bone) of an Eocene rodent. The mouse-like animal to which it belonged most likely lived in a tree, a burrow, or the undergrowth more than 37 million years ago! Although, to some people, this little bone may not be as exciting as those of, say, Tyrannosaurus rex, it thus has an important story to tell in the history of life on our planet.

Lauren Raysich is an undergraduate student at the University of Pittsburgh who volunteers in the Section of Vertebrate Paleontology at Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences working at the museum.

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Ask A Scientist – What Kind of Dinosaur is a Megaraptorid?

Are megaraptors really raptors? Assistant Curator and Head of Vertebrate Paleontology Dr. Matt Lamanna discusses what paleontologists know about the dinosaur family Megaraptoridae in our latest Ask a Scientist! See a life-sized replica of a megaraptorid thumb claw from Patagonia up close and find out how a claw like that led researchers to give megaraptorids their name.

 Ask a Scientist is a video series where we ask our research staff questions about the millions of amazing objects and specimens stored in our museum collection. Tune in on YouTube, and submit your own questions via Twitter @CarnegieMNH!