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When
It occurred 23.03 to 5.3 million years ago, following the Oligocene, and preceding the Pliocene.
Geographic Landscaping
Mountain ranges began forming in North America, along with the expansion of grasslands. Australia experienced an increase in climate due to its movement north. Eurasia underwent drastic tectonic rearrangements. The Tethys Sea connection between the Mediterranean and Indian Ocean was severed in the mid-Miocene causing an increase in aridity in southern Europe.
Life Forms
The Miocene was known for the expanding open vegetation systems (deserts, tundra, and grasslands), while at the expense of closed vegetation systems, such as forests. As a result, many animal species evolved into fast-running herbivores, large predatory mammals and birds, or small quick birds and rodents. By the end of the Miocene, 95% of all modern seed plant families existed. No plant species since the middle of the Miocene have gone extinct. Kelp forests began to appear, along with the retreat of tropical forests.
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For the final installation of Tours Through the Peabody, we visited the Vertebrate Paleontology collection. Our tour was lead by Christopher Norris, Senior Collections Manager of the collection. Throughout the tour, he constantly asked if he was talking too much; I honestly would have listened to him talk for hours! He made something that most would be bored by completely fascinating. Dr. Norris showed us specimens from multiple periods in geologic time, and explained how it was possible to determine climate change throughout the Earth's history by the various features on each specimen. For example, the teeth of Mammoths and Wooly Rhinos indicate tundra grazing, which indicated colder climates.
Dr. Norris also showed us how evolution can be noted, and corrected some misconceptions about evolution. Most believe that evolution is just retaining the most effective features and losing the rest. However, it often works the other way as well. He showed us the fossilized skull of a Hyaenodon, an ancient canine that terrorized Eurasia, North America, and Africa approximately 26 million years ago. This animal had razor sharp teeth that could only eat meat. He then showed us the skull of a Dire Wolf. Dire Wolves live up to their ferocious nature on Game of Thrones, as you would not would have wanted to encounter one of these canines. These animals skull, while larger than the Hyaenodon. had a specific feature distinguishing it from its ancient cousin: the teeth. Dire Wolves were actually omnivorous; their teeth allowed for a small amount of vegetation to be eaten. Given the wide geographic range Dire Wolves had, this makes sense. Dr. Norris said that it was fairly common for this kind of "de-evolution" to occur. One would assume that the teeth would evolve to be even more effective more eating meat. However, as the wolf expands its diet, it increases its chances of survival.
Once Dr. Norris stepped out, one of his graduate students, Matt, allowed for us to look more closely at the collection. I found one of the coolest things in my life, and hid in the corner looking at it as everyone else obsessed over something else on the other end of the collection. As I was roaming through one of the cabinets, I discovered a drawer label "Ursus spelaeus." I immediately got excited, as I knew that this was a famous cave bear. Bears have always been my favorite animal, and I have been affectionately dubbed Mama Bear by my friends. Needless to say, a bear skeleton, let alone a cave bear skeleton, was an exciting find. The skull was too high up in the cabinet, and a 5'2" girl like me was not equipped to take down a heavy skull like that. I was able to admire it from down below, though, and it was massive. I did get to hold the femur from the bear, though, and it was an extraordinary experience. I have been obsessed with the Ice Age since I was a small child, and being able to hold the bone from such an ancient, exceptional creature was almost a gift. I felt in that moment connected to it somehow, and knew that we are much closer than one would think. The power I felt from that animal as I held its bone was unlike anything I have ever felt before. As strange as this sounds, I wanted to thank the bear for allowing me such an intimate view of it.
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This week went from bonding sessions to collection explorations in a matter of hours. Kristine and I spent most of Tuesday discussing our education and career goals, with fun facts about our lives thrown in to spice it up. We worked on our dichotomous key for our invertebrate paleontology cart for Sci-Corps in the morning, tweaking the descriptions of each fossil to make it more accessible for museum visitors. The afternoon was spent researching colleges and the requirements for majors that we are considering studying. I am interested in Geology as I want to be a Paleontologist, and Kristine is conveniently a Geology major, so she talked to me about what it's actually like to major in Geology.
On Wednesday Gayatri was able to join us, and we continued to work on our key for the cart. We spent the morning researching the fossils, and then visited Dr. Susan Butts in her lab, where we will begin work next week. She took us on a mini-tour of the Invertebrate Paleontology collection, teaching us about a few different fossils related to our cart. Susan also showed us one of the drawers full of insect fossils, which we will be cataloging this summer as well. Afterwards, we went on a science adventure in one of the museum's storage areas, and each selected an un-labeled fossil which we each have to try and identify. Gayatri figured hers out fairly quickly, while I still have no idea what mine could be. I guess we'll have to find out next week!
Thursday was another mellow day. We started our morning discussing an article about the lack of women in STEM related fields, and some of the factors that discourage women from pursuing post-doctoral research. It was an intense discussion lasting nearly forty minutes, after which all three of were tired and frustrated. Being that we are all women studying/planning on studying STEM fields, it is upsetting to know that these challenges exist outside of our fairly protective bubble. We then spent some time looking at the online catalog for the museum, selecting fossils that we want to use on our cart. Afterwards, we spent the rest of the afternoon down in the lab with Susan, who lead us through the process of taking a fossil out of the collection.
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