Carnegie Museum of Natural History

One of the Four Carnegie Museums of Pittsburgh

Vertebrate Paleontology

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Pebble or Jaw?

by Jay Margolis

partial jawbone and bone fragment fossils

It can be difficult to find fossils when working on a microscopic scale. The partial jawbone and bone fragment above are each less than a centimeter (0.4 inches) in maximum diameter, but their small size makes them no less important to paleontologists and other researchers. Even diminutive fossils such as these can be used to help scientists determine the diet or behavior of extinct animals, as well as to piece together what kind of environment they lived in.

fossil measuring

Even with the help of microscopes, it can be hard to tell such fossils apart from the tiny rocks and sediment that they are often mixed in with. After spending a long amount of time practicing and studying, telling fossil apart from rock can become easier. However, for those who have not had as much practice, there are a few easy ways to help distinguish the two.

One of these ways is to look for striations, or organized and consistent lines. These lines are all oriented in the same direction and can be seen on the surface of some fossils as an indicator of past bone growth. Another way is to look for pores, circular holes that would be visible in a cross-section of a fossil bone. These holes indicate where blood vessels once carried nutrients throughout the bone.

Both of these textures can potentially be seen in a disorganized fashion on rocks and minerals. However, seeing these two textures together, and arranged in an orderly way, is among the best indicators that the rock you thought you were looking at is actually a fossil.

Jay Margolis is an intern from Chatham University working in the Section of Vertebrate Paleontology at the 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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My Guildey Pleasure

By Andrew McAfee

As the Scientific Illustrator for the Section of Vertebrate Paleontology at Carnegie Museum of Natural History, I spend most of my time in the museum interpreting and representing the paleontologists’ work in visual form. Most of this work takes place at a desk with a computer. But as a member of the Guild of Natural Science Illustrators (GNSI), I spend one week per year away from the desk, learning new techniques in the field and sharing a few of my own.

The GNSI is an organization of scientists and science illustrators founded in 1968 by illustrators at the Smithsonian Institution in Washington, DC. The purpose of the GNSI is to advance science illustration by facilitating the exchange of ideas, knowledge, and techniques among its members.

Every year around July, the GNSI has a conference that brings members from all around the world together for a week of plenary speakers, technique expositions, lectures, and workshops. It’s a wonderful opportunity to commune with colleagues in the field of scientific illustration and acquire new perspectives and technical abilities.

Andrew McAfee with his digital painting of Mansourasaurus 
Andrew McAfee with his digital painting of Mansourasaurus (upper left) on display in GNSI’s 50th anniversary exhibition, Visualize: Art Revealing Science, at AAAS headquarters. Photo: Reid Psaltis.

I joined the GNSI in 2013 and have not missed a conference since. This year’s event marked the 50th anniversary of the Guild’s formation and represented a homecoming, returning to Washington, DC. As a part of our anniversary celebration, the American Association for the Advancement of Science (AAAS)—known for, among other things, publishing one of the world’s foremost scientific journals, Science—hosted our annual members’ juried exhibition.

This year I was honored to have two pieces selected for exhibition in the show: my reconstructions of the recently-named dinosaurs Mansourasaurus shahinae and Tratayenia rosalesi, both completed at Carnegie Museum of Natural History under the guidance of paleontologist Matt Lamanna. I was proud to represent the museum and it was gratifying to see my work sharing walls with the stellar work of my colleagues in the AAAS gallery.

Visualize: Art Revealing Science, the 50th anniversary GNSI exhibit, will be on display at AAAS headquarters until October 15, 2018.

Andrew McAfee is Scientific Illustrator 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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The Two-Headed Dinosaur

Apatosaurus is a sauropod, or long-necked plant-eating dinosaur, that lived in western North America during the late Jurassic Period roughly 150 million years ago. In the early 20th century, scientists couldn’t agree on what kind of head Apatosaurus had. No skull had ever been found attached to a neck of this dinosaur. So, when Carnegie Museum of Natural History mounted its most complete Apatosaurus skeleton in 1915, it did so without including a skull.

Apatosaurus louisae (right) as it was originally mounted in 1915, without a skull. At left is the skeleton of its relative Diplodocus carnegii.
Carnegie Museum of Natural History’s skeleton of Apatosaurus louisae (right) as it was originally mounted in 1915, without a skull. At left is the skeleton of its relative Diplodocus carnegii, better known as ‘Dippy.’ Credit: Carnegie Museum of Natural History.

The mount stood headless until 1932, when the museum followed prevailing scientific opinion of the day and placed a blunt-snouted, broad-toothed skull on the Apatosaurus. It remained there for another 47 years.

Apatosaurus and Diplodocus skeletons
Apatosaurus (right) and Diplodocus, ca. 1932, after a skull of the blunt-snouted sauropod Camarasaurus lentus had been mounted on the Apatosaurus skeleton. Credit: Carnegie Museum of Natural History.

In 1978, however, Carnegie Museum of Natural History paleontologist Dave Berman and museum research associate Jack McIntosh reasoned that a very different, more Diplodocus-like skull found with the Apatosaurus skeleton back in 1910 was most probably the correct one. A subsequent discovery of a still-connected Apatosaurus skull and neck proved them correct. In 1979, the museum’s Apatosaurus louisae was finally fitted with its proper skull – more than seven decades after its discovery! It remains that way today, on public exhibit in the museum’s dinosaur gallery, Dinosaurs in Their Time.

Apatosaurus Louise
Apatosaurus as it looks today, displayed with its correct skull, which closely resembles that of its relative, Diplodocus. Credit: Melinda McNaugher, Carnegie Museum of Natural History.

Matt Lamanna is a paleontologist and the principal dinosaur researcher at Carnegie Museum of Natural History in Pittsburgh.  Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

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Did you know that the Section of Vertebrate Paleontology’s…

t. rex in Dinosaurs in their Time

Did you know that the Section of Vertebrate Paleontology’s collection contains more than 460 type, or original, specimens? Type specimens are the specimens upon which individual species are (and always will be) based.

Among these Carnegie type specimens are those of several well-known dinosaurs—Diplodocus carnegii, Apatosaurus louisae (aka ‘Brontosaurus’), and the ‘Chicken from Hell’ Anzu wyliei.

We also have the type specimen of most famous dinosaur of all, Tyrannosaurus rex!

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Antarctic Peninsula Paleontology Project featured by NSF

two explorers in the distance on a flat, baren part of antartica
Photo courtesy of AP3 team member Dr. Meng Jin, Curator-in-Charge of the Division of Paleontology at American Museum of Natural History

Dr. Matt Lamanna, Carnegie Museum of Natural History’s Assistant Curator of Vertebrate Paleontology, served as the lead Principal Investigator and Project Director of the Antarctic Peninsula Paleontology Project (AP3). Photos of their expedition were recently featured through The National Science Foundation’s showcase on Discover magazine’s website entitled When Dinosaurs Roamed Antarctica. Check out the link for some of the stunning photos from their trip!

http://discovermagazine.com/galleries/2018/frozen-fossils

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The Dinosaur of a Lifetime

color drawing of a dinosaur on a beach
(Image credit: Carnegie Museum of Natural History / Andrew McAfee)

By Matt Lamanna

It might sound a little strange to say, but African dinosaurs have been an important part of my life for a long time. Almost two decades ago, when I was in graduate school at the University of Pennsylvania, and a few years before I took a job here at Carnegie Museum of Natural History, I participated in fossil-hunting expeditions to the Sahara Desert of Egypt. Along with our advisor, my beloved “Boss” Peter Dodson, my fellow students and I had a lot of success, discovering among other fossils the only known skeleton of a new, ~95 million-year-old species that we named Paralititan stromeri in 2001. With a humerus, or upper arm bone, that’s almost as tall as I am, Paralititan is still one of the biggest dinosaurs known to science.

But as fun as those discoveries were to be a part of, some of our team’s most sought-after finds never materialized. In going to Egypt, part of our aim was to find dinosaurs from roughly 80 to 66 million years ago – dinosaurs from the very end of the Cretaceous Period, the third and final time period of the Age of Dinosaurs. Dinosaur fossils of this age are exceedingly rare on all of continental Africa (i.e., Africa excluding the island of Madagascar), not just in Egypt. Surprisingly, however, this has not stopped paleontologists from speculating as to what kinds of dinosaurs might have inhabited Africa at the end of the Cretaceous. Some have proposed that African latest Cretaceous dinosaurs were close relatives of, and therefore similar to, those living on neighboring landmasses at the same time. Other scientists have argued that Africa was an island continent at the end of the Cretaceous, and, because it was cut off from other land areas, it was home to unique dinosaurs that had evolved for millions of years along their own distinctive evolutionary pathways.

Until recently, no one had ever found a reasonably complete dinosaur skeleton from the end of the Cretaceous anywhere on continental Africa. A few isolated bones and minor parts of skeletons had been discovered, but these didn’t tell us much about the dinosaurs to which they belonged – as you can imagine, the more pieces one has of a fossil skeleton, the more one can typically learn about the animal it represents. This, in turn, prevented paleontologists from figuring out whether African latest Cretaceous dinosaurs were truly unique or whether they had close kin on other landmasses. But all of that changed in late 2013, when my friend and colleague Dr. Hesham Sallam of Mansoura University in Egypt—along with his talented students Iman El-Dawoudi, Sanaa El-Sayed, and Sara Saber—discovered the skeleton of a sauropod (long-necked plant-eating dinosaur) at an ~80 million-year-old site in the Dakhla Oasis of the Egyptian Sahara. The dinosaur I’d dreamed about for virtually all of my professional life had finally been found! Even better, Hesham and the team—which also included my close friends Pat O’Connor and Eric Gorscak, plus several other Egyptian and American scientists—invited me to be a part of the study. We soon realized that the creature had a lot to say about the nature of Africa’s last dinosaurs, as its bones suggested close relationships to species living in Europe and Asia at about the same time. These hypotheses were borne out by more rigorous analyses, showing that African latest Cretaceous dinosaurs weren’t island-dwelling weirdos after all – rather, they had close cousins in Eurasia. Today, our team gave the dinosaur its formal scientific name, Mansourasaurus shahinae, and for me, it’s the culmination of a search that’s occupied almost half my life.

Matt Lamanna is a paleontologist and the principal dinosaur researcher at Carnegie Museum of Natural History in Pittsburgh. 

Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

Read more about this news on Gizmodo.