The first non-aristonectine elasmosaurid (Sauropterygia; Plesiosauria) cranial material from Antarctica: New data on the evolution of the elasmosaurid basicranium and palate
O’Gorman, J.P., Coria, R.A., Reguero, M., Santillana, S., Mörs, T., Cárdenas, M. Summarized by Sarah Sheffield
What data were used?
New fossil material from Vega Island in Antarctica
The fossils were prepared using tools like a jackhammer to remove the fossils from surrounding rock. The fossils were then measured using digital calipers.
Rare fossil material recently found from Vega Island in Antarctica shed light on the evolutionary relationships of extinct reptiles, the plesiosaurs. While a lot of plesiosaur material has been found in the past in Antarctica, this particular field study turned up skull material, which is quite rare! The skull material preserved multiple features that allowed researchers to better understand the evolutionary relationships between different groups of plesiosaurs. Specifically, features of the palate in the skull, has features that link it to other groups of plesiosaurs, the elasmosaurids.
Why is this study important?
This study is important for many reasons! First, it described very rarely preserved parts of the body (namely, the skull), which preserves a ton of information about its evolutionary origins. Second, Antarctica remains very unexplored for fossils; it is very expensive and difficult to travel and do field work in this part of the world. This means that with every new fossil find, our knowledge of the past history of Antarctica grows tremendously!
The big picture
New fossils from Antarctica provide new information concerning the biodiversity and evolutionary relationships of plesiosaurs from the Cretaceous. As Antarctica remains fairly unexplored for fossils, any new fossil finds contribute greatly to our knowledge of the history of the continent.
O’Gorman, J.P., Coria, R.A., Reguero, M., Santillana, S., 2017, The first non-aristonectine elasmosaurid (Sauropterygia; Plesiosauria) cranial material from Antarctica: New data on the evolution of the elasmosaurid basicranium and palate: Cretaceous Research, v. 89, p. 248-263, doi: 10.1016/j.cretres.2018.03.013
This post is a continuation of my first post, the geology of Acadia National Park. To recap for those of you who might not have read my first post, I documented all the geology I saw recently on a vacation my husband and I took to Maine and New Brunswick, Canada. This post will be all about the geology of the Bay of Fundy! Specifically, this will be about how glaciers have shaped the geology of the area.
The Bay of Fundy is an incredibly famous geologic area for a good reason-it has the highest tides on Earth, with the highest reaching nearly 56ft! The reason why the tides are so high here has to deal with the shape of the bay-the bay narrows quite a bit (as you can see from the map), so as all the water enters the bay, it’s forced to stack up on top of each other, making the tides reach these incredible heights.
Glaciers have shaped a lot of the geology along the Bay of Fundy; as glaciers advance and retreat, they leave telltale signs. One of the best signs are when you see rocks called tillites. These rocks are made of glacial sediment. They’re fairly easy to recognize-often, you’ll see rocks with very large, poorly sorted clasts (meaning, all kinds of different sizes of sediment). These are left behind by glaciers! Here is an example of tillite along the coast of the Bay of Fundy. Look at all of the different sizes of clasts in there! This rock was found at the Irving Nature Center, St. John, New Brunswick. The wave energy in this particular area is very high, which you can tell by the lack of small sand grains and the prevalence of much larger clasts (pebbles-boulders). Another sign of glacial activity is the presence of striations on rocks. Striations are scratches in rocks that are caused by glacial ice moving over them. These glaciers can have lots of rock and sand debris within it, so as they move over rocks, it can cause a lot of surface damage to the rock. Check out this picture of striations on volcanic rocks, also from the Irving Nature Park!
Arguably, the most famous area of the Bay of Fundy is the site called Hopewell Rocks. I’ll discuss a lot more about the Hopewell Rocks in my final post, but for now, let’s talk about how glaciers shaped these famous rocks. As glaciers last retreated from these areas (meaning, the Earth warmed and glacial ice melted), the water from the glaciers filled into the ground and caused cracks to form along the coast. This is called chemical weathering. Water is a chemical and it’s the most common chemical that rocks come into contact with when we’re talking about chemical weathering. These cracks eventually caused these large rocks to be separated from the cliff line. This phenomenon might be more familiar to you when you’re driving- when roads (in colder areas, especially) have small cracks in them and water gets into those small cracks, that water can freeze, causing the crack to expand. After multiple rounds of freezing and melting, these cracks become a real problem to drivers!
During our next (and final) piece about my trip through the Bay of Fundy, we’ll look at how these famous rocks are shaped by mechanical weathering, instead of chemical!
I recently went on a trip with my husband to Maine, USA and New Brunswick, Canada to see some of the best geology these places had to offer! I’ll be showing you a lot of the gorgeous geology (and some cool biology!) through a series of posts. This first post will be all about my trip to Acadia National Park. My husband and I hiked quite a few trails (about 20 miles of trails total!) in the four days we were there and we learned quite a lot about the geology of the park from our adventures.
A lot of the rock you’ll see in the popular parts of Acadia- especially the trails in the main part of the park-will be granite. Granite is an igneous rock that formed intrusively, meaning, it formed under the surface of Earth. You can generally tell whether igneous rocks formed intrusively or extrusively (on Earth’s surface), because the sizes of the grains will be different. The magma that makes up granite cools very slowly under the surface of Earth-the slower it cools, the larger the crystals are! But, I digress. Many of the mountains in the Acadian region are made of granite. This granite was formed when two continents- Laurentia (North America) and Avalonia (eastern North America and western Great Britain) slammed together hundreds of millions of years together. When they collided, it forced a huge amount of magma to pool, creating the famous granite we see today (you can read a lot more about the creation of Acadian rocks at this site)! Here’s a photo of me climbing some of this granite on the Beehive Trail! The mountain is very steep and the trails are very narrow, so it is most safely climbed using metal ladders!
Granite is a very hard, stable rock. What that means is that it doesn’t weather away easily, like other rocks (think of how marble gravestones look like after a few decades-marble is much more easily worn down!) But after millions of years, even the toughest of rocks can start to be broken down! Take a look at these rocks here-you can see the cracks from being weathered (likely by rain!)-these cracks allow rain to penetrate into the rock and break it down even faster! To put it into perspective, think of a windshield-if you put a single crack into it, you’ve weakened the glass and further pressure can result in faster spreading of the break. Rocks respond similarly after the first cracks are formed!
I want to show you some of the cool pictures from the other side of Acadia now. This is a lesser known, but just as beautiful part of the park as the most well known part of Acadia. This area is called Schoodic Point. This is also dominated by the same gorgeous granite-but it’s got something else going on that’s really spectacular. If you take a look, you’ll see the gorgeous light colored granite…but also, intrusions of a dark colored igneous rock (called a diabase); this diabase has tiny crystals-meaning, it cooled quickly! We can tell that the dark colored rock intruded into the granite because of the Principle of Cross Cutting Relationships; this geologic principle means that if a rock “cuts across” another rock, the rock that is cutting across is younger (read more about geologic principles here).
So, with that in mind, these diabase intrusions are the remnants of later episodes of volcanic activity. There are multiple episodes of volcanic activity represented here-many of the intrusions are cut by even more intrusions! What a beautiful place. So even though this is a post about geology, I wanted to show you a little bit of the life here at Schoodic Point-the wave activity at this area is VERY high (one easy way to see that is that there’s very little sand at this coast-the wave energy is too high, so the sand gets washed away). The water crashes up onto the granite and some water will stay up there, giving a perfect spot for lots of little critters to form a home! Take a look at this small pool of water-how many critters can you see?
Whole-body endothermy in a mesopelagic fish, the opah, Lampris guttatus
Wegner, N.C., Snodgrass, O.E., Dewar, H., Hyde, J.R Summarized by Sarah Sheffield
What data were used?
Captured and freely-swimming opah fish
Researchers measured the body temperatures of captured and freely swimming fish at their natural depth. Temperatures were taken in multiple places along the fish, including the temperatures of a number of the muscles. These measurements were taken by heat monitoring sensors placed in the muscles of the fish.
Researchers found that the core of the fish (pectoral muscles, heart, etc.) were much warmer than the surrounding environment. The cold, oxygenated blood of the fish is warmed by the conducting of heat from the warmer, deoxygenated blood leaving the respiratory system before the oxygenated blood reaches the respiratory system. This indicates that these fish, just like humans and all other mammals, are able to produce their own body heat (“warm blooded”) as opposed to creatures like reptiles, who rely on external sources, like the sun, to maintain their temperature (“cold blooded”).
Why is this study important?
We’ve all learned from school that critters like reptiles and fish are cold blooded, whereas mammals (like us) are warm blooded. Simple, right? It turns out, it’s not nearly as simple as that! More and more, scientists have begun to discover that there are many animals that don’t fit into these neat categories, the opah fish being the most recent of these. This is important because in the fossil record, we don’t have the luxury of examining animals while they’re still alive, so we need to look for other clues! Dinosaurs and pterosaurs are excellent examples of this-we’ve always thought reptiles were cold blooded. But dinosaurs, like Velociraptor, had feathers! They had larger brains! Pterodactyls could fly by flapping their wings! All of these are examples of warm-blooded behavior. Fish like the opah show us how what we thought we knew might not always be the case!
The big picture
The picture that I want to stress here is that even the big things we thought we understood in science-like who’s warm and cold blooded-are subject to change with new data! Only within the last few decades have scientists begun to ditch the idea that animals fall neatly into categories of “warm” and “cold” blooded. It’s also important to note that discoveries such as these open our interpretations of extinct organisms-like dinosaurs, pterosaurs, and yes, even fish!- and how they were able to generate energy. Since we can’t bring a live pterodactyl (at least, not yet! Maybe we’ll learn more after watching Jurassic World: Forgotten Kingdom) in for testing, data such as these remind us that life isn’t as simple as just ‘warm’ and ‘cold’ blooded.
Wegner, N.C., Snodgrass, O.E., Dewar, H., Hyde, J.R., 2015, Whole-body endothermy in a mesopelagic fish, the opah, Lampris guttatus: Science, v. 348, p. 786-789, DOI: 10.1126/science.aaa8902
I’m in my first year of teaching at the University of South Florida. I’ve had almost 700 students come through my classroom, just in my first two semesters! I wanted to write a little bit about what I’ve learned about making my lectures work for students of all different backgrounds. USF is a wonderful place to do this because our students come from every background imaginable! We have students from nearly every country on Earth, every native language, religion, socioeconomic and veteran status, etc. imaginable! It’s one of the things I love most about USF- I get to learn all about the world through my students. This unique community also presents me with the opportunity to make my lectures and my teaching style accessible to students who are English language learners (ELLs)-you may have referred to these students as ESL (English as a second language) in the past-educators have moved away from using that term because many students are actually learning English as a third and even fourth language! A large percentage of USF students are classified as ELLs-and they come from all over the world! Just in the past year, I’ve had the pleasure of working with students from Brazil, Venezuela, Nigeria, Germany, Finland, Russia, China, Japan, Oman, Saudi Arabia, Palestine, and more.
The introductory course I teach-History of Life-is very heavy in scientific jargon, no matter how you slice it (e.g., the names of dinosaurs, geologic time periods, etc.), so I’ve been working with my ELL students to help them feel more confident in the class. I’ve listed some of the methods I’ve found useful below!
All of my exams have short answer components, where they have to take scientific evidence and present conclusions. I write 2-3 questions per lecture topic and post them as a discussion board on Canvas (or Blackboard, or any sort of other online gradebook/digital classroom environment). I have seen dramatic improvements in the confidence levels of ELL students, as well as native English speaking students, when handling the essay portions of the exam. Allowing them to practice their communication skills in advance has allowed them to excel. I never tell the students which questions I am choosing for the exam, but this way, students can post their answers on the discussion boards, so that I can spend a few seconds working with them one-on-one. It might seem like a lot of work, but truthfully, it’s only about a ½ hour out of my week, usually.
The geologic time scale
To help students learn these very odd words more easily, I have located geologic time scales in as many languages as possible. Students who speak languages, especially, that aren’t rooted in the Roman alphabet have found that it is much easier to make connections with these terms. (The ICS has a bunch of those time scales listed here)
A vocabulary list
As a rule, my exams are not about vocabulary. Meaning, my multiple choice or essay questions are not asking you to define terms-students have to use the terms to explain phenomena we see in the geologic record. However, the amount of vocabulary in a science class is daunting for many, so one way that I can boost students’ confidence is to provide a list of vocabulary I expect them to know (e.g., Tyrannosaurus, Devonian, albedo) so that they know on the exam what words they will be expected to know.
Posting unfamiliar terms on the PowerPoint slides
I generally don’t use too much text on my slides-but I do make sure to put the topic of the slide, any scientific words, and image descriptors on the slides (or at least in the notes). This helps students who may feel overwhelmed with just trying to figure out vocabulary words merely from me saying them out loud (English words really aren’t the easiest to spell, are they?)
Using familiar words
I’m still working on this one, for sure. I try to make sure that my lectures and my exams use common words. For instance, I have used words like ‘hypothetical’ and ‘plummet’ before on exams. ELL students who might be unfamiliar with some of these words can often feel overwhelmed. I do my best to a) make sure students know that they are welcome to ask me to define non-vocabulary words b) provide alternatives to these words on the test (for example-hypothetical (imaginary)) or c) avoid using words (e.g., use “drop sharply” instead of “plummet”) that might add to the stress of exam day.
Only assign videos that have great subtitles
I have my students watch a number of documentaries to learn more about certain materials. However, I have noticed that a number of videos posted on, for example, YouTube, might not have reliable captions, making it very difficult for ELL students to fully capture the science presented.
Use the microphone
My classes are big-my largest is just under 200 students. I am not a very loud person, usually, but if I need to, I can make myself heard for a 75-minute lecture. However, many students find it harder to understand words if they cannot hear them as loudly and as clearly. Using a microphone relieves the stress of many students. Even if you feel that you are loud enough, still consider using the microphone! (Bonus-this is also a huge help for hard of hearing students).
These techniques are meant to help my students feel more confident about their knowledge in my class. By making these small changes, I have found that my class is much more accessible to a larger percentage of the class and that students are giving me better and more detailed answers and they are able to make higher-level scientific deductions-which is what any science instructor wants, right? As an added bonus, many of these methods are also very helpful to students from any background who aren’t so confident in their writing skills, or who missed class due to illness or emergency, or to students with accommodations (e.g., ensuring that there are captions on videos and that your PowerPoint slides have image descriptions) also allows Deaf and hard of hearing students to have full access to your class, too! I hope that I can continue to make my classes more accessible-if you have any tips, please feel free to comment below!
Late Ordovician (Hirnantian) diploporitan fauna of Anticosti Island, Quebec, Canada: implications for evolutionary and biogeographic patterns
Sarah L. Sheffield, William I. Ausich, Colin D. Sumrall
What data [were] used? New fossils found from Anticosti Island in Quebec, Canada.
Methods: New fossils of poorly understood echinoderm (relatives of sea stars) fossils discovered from Upper Ordovician (445-443 million years ago) rocks were analyzed and compared with middle Silurian (434-428 million years ago) to better understand biogeographic and evolutionary trends.
Results: The Holocystites Fauna is a group of poorly-understood diploporitan echinoderms (a term that just means they breathe out of sets of double pores found on their body) that scientists assumed to have only lived in the midcontinent of the United States (e.g., Tennessee, Iowa, Indiana, etc.) during a very specific time within the Silurian. New fossil species Holocystites salmoensis, however, tells us that they actually also lived during the Late Ordovician of Canada, which extends their known range nearly 10-15 million years!
Why is this study important? So at first glance, this paper might not seem so important-it’s just one new fossil of a relatively rare group of echinoderms. What is so important about this is the time in which these fossils were found. Rocks from the Upper Ordovician, during which this fossil was found, are very rare because the ocean levels were very low. Earth was in an ice age, so a lot of ocean water was taken up in glacial ice. When sea levels are low, fewer rocks are preserved; therefore, fossil data from low sea levels are rare. Evolutionary transitions of fossils from the Ordovician through the Silurian aren’t well understood. Now that we’ve found evidence of Ordovician Holocystites, we can infer a lot more about when and how these organisms evolved.
The big picture: Crucial information about how life on Earth evolved is often hard to find from times like the Late Ordovician. Actively searching for rocks during these times and identiying fossils from within them can tell us a lot about how past life responded to mass climate change (like ice ages and significant warming periods). It can also tell us a lot about how organisms expanded and shrunk their biogeographic range. Even one new fossil, like the one identified in this paper, can change a lot about what we think we knew!
Citation: Sheffield, S.L., Ausich, W.I., Sumrall, C.D., 2017. Late Ordovician (Hirnantian) diploporitan fauna of Anticosti Island, Quebec, Canada: implications for evolutionary and biogeographic patterns: Journal of Canadian Earth Sciences, v. 55, p. 1-7, doi: 10.1139/cjes-2017-0160
Last summer, I went to southern Indiana to do some fieldwork with my undergraduate research student, the wonderful and intelligent Sarah Johnson (who has since graduated and gotten an excellent job working at an environmental consulting firm in Texas). We went there to collect data to answer a really intriguing question that, I am very sorry to report here, we still do not have an answer to. This post is about fieldwork, undergraduate research, and even more importantly, the importance of reporting the experiments and the field expeditions that just didn’t work out.
I work on a group of unusual extinct echinoderms, the diploporitans (you can read more about them here). One of the many weird things about this group of echinoderms is that no one can find fossil evidence of them as juveniles- we only find them as adults. All living echinoderms have a free-swimming larval stage- meaning, even the echinoderms that don’t move much as adults (like crinoids) are quite mobile as juveniles! For other groups of fossil echinoderms (like blastoids), there are plenty of examples of very small juveniles that likely moved the way that modern ones do-as larvae. However, there’s no known fossil evidence for this in the diploporitans.
So my student, Sarah, and I went to the one place in the United States that we would expect to find juveniles, if there are any to be found- Napoleon, Indiana. The reason that we would expect to find juveniles is that there are a very large number of preserved adults there-which makes it more likely that smaller ones would also be there (too small to see with your eyes). Sarah and I searched the outcrop for hours looking for the areas that had the highest density of fossils, collected about 50 lbs worth of sediment, and drove back to Knoxville, TN.
Sarah and Russell Godkin, my other undergraduate research student, then spent the rest of the summer sifting through the seemingly endless buckets of sediment that we brought back-they used microscopes and analyzed the smallest sediment grains for all fossils. They pulled out thousands of tiny corals, brachiopods, and pieces of crinoids. However, after countless hours, they didn’t find a single diploporitan juvenile-not. a. one.
Obviously, we were all quite disappointed-we really wanted to find these fossils (and Sarah and Russell were really tired of looking into microscopes-but I digress). There’s an important lesson in here, though- the LACK of an answer is just as important. The lack of an answer can help us develop new hypotheses as to why we can’t find these juveniles and it can help other scientists better understand related questions about echinoderms and fossil preservation. So-never fear, the hunt to figure out what juvenile diploporitans looked like is still on!
Scientists are increasingly concerned with climate change. You might feel helpless, as you watch the news-you see images of awful pollution, dying coral reefs, melting glaciers and to me, it can be overwhelming! We all know how to cut carbon emissions- drive our car less (or buy a hybrid car!), support renewable energy, and get solar panels for our houses! However…if you’re like me and you live in an area where you can’t really get by without a car and you may not have the means to do much about getting a hybrid or solar panels, this advice may not be so helpful. So today’s post is dedicated to SUPER EASY WAYS to reduce your carbon footprint. Spoiler alert: many of these will also save you money! Double win!
1. Stop buying paper napkins! Paper alone makes up approximately 16% of US landfills. You can cut down on the number of napkins that you contribute to a landfill by purchasing a one-time set of cloth napkins. I made the switch a year ago! I spent about $30-50 a year in paper towels and napkins for 2 people. I purchased a $13 set of napkins 2 years ago, and haven’t bought another napkin since. I toss them in the wash with my regular laundry and I love them! They also make my not- so-fancy meals of cereal and toast feel even fancier! Try this set by clicking here.
2. Stop buying dishwashing sponges! Sponges are seriously one of the most germy things in our house-many studies have shown that the average sponge holds more bacteria than your bathroom- and, as an added detriment, you have to throw them out pretty frequently. I just discovered an awesome alternative: silicone sponges that are antimicrobial AND dishwasher safe! I wash all of my hand washable dishes with them, clean my sinks and counters, and pop them in the dishwasher-no waste and I feel so much better that they’re not harboring bacteria. Try this set by clicking here.
3. Invest in silicon freezer bags! So, one of the hardest things for me is to reduce my need on plastic-I’ll admit it! One of the best things I’ve discovered on my journey to make small efforts that add up to a lot are silicon freezer bags. They have completely replaced single use freezer bags for me! I buy my food in bulk and freeze them in separate bags-these silicon bags are airtight and keep my food frozen nicely. When it’s time to thaw them out, I just take the bag and wash it in hot water or the dishwasher (yes, this even works with meat like chicken!). The bags were a little pricy-about $20- but I haven’t bought freezer bags in just under 2 years. Consider the savings-each set of freezer bags is about $3-5, depending on where you get it. If you bought a set of freezer bags even once every two months, you’re still looking at a LOT of money saved! Better yet, I use these bags to pack sandwiches, hold jewelry when I’m traveling, and store leftovers from dinner. Try these – click here.
4. Cut down on meat just a little bit-especially beef! Cows actually burp a little bit of methane when they eat-which is all of the time! Our reliance on beef is a major cause for carbon emissions across the globe. Consider eating more turkey and chicken, or, better yet- just cut down on meat once or twice a week! There are so many excellent dinner choices that are vegetarian (and those meat substitutes you can get in the freezer aisle are actually pretty darn delicious now!) Added bonus- it can cut down on your grocery bill, even by removing meat from your diet a few times a week!
5. Reduce your takeout packaging. Takeout food waste can exceed the amount of carbon emissions that cars produce each year! Next time you’re at a restaurant, request that they don’t give you a straw (think about using reusable ones, like these), don’t take more than a few paper napkins, ask that they don’t give you more condiments than you need, refuse the plastic bag they put the food in, and try not to do the carry out option as much and eat there, to cut down on the packaging that has to be used! Any reduction in waste will help.
6. Don’t use plastic grocery bags! Bring your own OR, if you don’t buy that much, refuse a bag altogether. Many stores (like Target) will give you a small discount for bringing your own reusable bags! You can even replace the plastic produce bags at the store with these – click here.
Remember, being environmentally friendly doesn’t have to be incredibly stressful. These small changes in my life have really cut down on my waste consumption. Please, do your best to reduce your carbon footprint-and enjoy all the money you’ll save with some of these tips! None of these tips were sponsored- I use all of these in my own life and love them! Statistics and general facts from the U.S. Environmental Protection Agency.
I was recently asked a question during a job interview- which level of students do you most enjoy teaching and why? I thought for a minute and then gave my answer-introductory level students-and the entire panel seemed surprised, which gave me the idea to write this post. Right now, I am a visiting faculty member at a huge university-my entire job is to teach a lot of classes every year. These classes can range from graduate seminars, upper level geology classes, to introductory level classes, where the majority of the students are only there to get their core requirement classes out of the way.
Don’t get me wrong- I love teaching and working with graduate students and geology majors. It’s a blast to work with students who care so much about the material already and who have a thirst to learn more. But what I really love teaching-and the teaching that I find to be the most impactful- is teaching those intro classes.
Nearly 90% of the students in my intro classes will never take another science class again. Most of them, on day one, probably don’t even want to be there-I am told by the students quite often that they’re terrible at science, or that they don’t have any interest in the subject, or even that they have learned some terribly untrue things about science (many of my students come in believing that science and religion are at odds with one another and can’t coexist peacefully-not true at all!). So why do I love teaching them? Quite simply, I am presented with an awesome challenge-to change their minds about science. With every semester, I am given the gift to encourage sometimes hundreds of students to explore the beautiful world of science. I get to show students volcanoes that burn bright blue because of the sulfur in the lava and show them reconstructions of how we think the earliest and weirdest of our ancestors might have lived. I get to help them learn to take a few pieces of evidence and draw conclusions and expose them to a new way of thinking. Geology is an incredibly fun and exciting science and to see intro level students get so engaged and passionate- and to let them see how passionate you are about this subject (seriously, I’ve gotten teaching evaluations that have said “too enthusiastic about science” before)- is a feeling that just can’t be beat.
However, this is also such an incredible responsibility- we have to teach them how science truly works and how to spot bad science, which is increasingly prevalent, in popular culture. We have a responsibility to help them see how their actions, like not recycling, have a direct affect on the people with whom they share the Earth. These classes help students form their opinions on the issues shaping our world today-is GMO food safe? Why do we care if evolution is taught in the classroom? Do we really need to be concerned about climate change? If this is likely the only science class they’ll take, this might be the only time they’ll ever learn how to form their ideas about the scientific issues facing our world-and most importantly, found their opinions based on scientific evidence. If, in a decade or so from now, at least a few of my students think back to their intro geology class with Dr. Sheffield and remember that they should really use those reusable shopping bags or that they might know how to correct someone’s misguidance on climate change or evolution, then I will have helped make a difference. And what could be better?
I wish I had had such an eloquent answer during my interview- but if I could go back, I’d say this: teaching these introductory classes is one of the most important things that we can do as scientists. Don’t take the responsibility you have to inspire a whole generation of enthusiastic and scientifically literate students lightly!
A mid-Cretaceous enantiornithine (Aves) hatchling preserved in Burmese amber with unusual plumage Lida Xing, Jingmai K. O’Connor, Ryan C. McKellar, Luis M. Chiappe, Kuowei Tseng, Gang Li, Ming Bai Summarized by Sarah Sheffield
What data was used? Newly discovered Cretaceous-age (~100-65 million years ago) amber specimens that contain parts of a bird hatchling; rarely found soft tissues of the plumage were also preserved. These specimens were found in Myanmar.
Methods: The specimens, encased in amber, were CT scanned using a micro CT scanner. Each preserved piece of the bird skeleton (e.g., neck, foot, etc.) were scanned separately. Researchers then did a 3D reconstruction of the bird, combining all of the scanned pieces.
Results: Researchers found that a number of the bones in this specimen were unfused, which indicates that the bird was very young (bones typically fuse as an organism grows-human babies do this too!). The specimen preserved two types of feathers: downy-type feathers and outer feathers, similar to birds today and to some of the earliest birds in the Jurassic, like Archaeopteryx, the famous bird-dinosaur transitional fossil.
Why is this study important? Feathers and other types of soft tissue are exceedingly rare in the fossil record! Typically, the only things that get preserved are bones, shells, and other hard tissues. Amber is one of the ways that soft tissue can be preserved; when we find soft tissue preserved, it’s certainly a reason to celebrate! This data can shed a lot of light on how organisms looked from millions of years ago. This hatching’s preservation tells us a lot about how feathers in juvenile birds looked from the Cretaceous, and can be compared to the other soft tissue feathers that have been found previously belonging to adult birds. The bones also provide more information on how skeletal changes of birds occurred from juvenile to adult stages.
The big picture: Soft tissue preservation is an incredible opportunity to learn about organisms that lived a very long time ago-other soft tissue fossils have shown us what dinosaur skin looked like, how organs of extinct mammals look, and more. As you can imagine, it’s also rare to find well-preserved juveniles in the fossil record (many groups of fossils don’t have juvenile representatives at all!), so when we do find examples of younger organisms, it’s important to study them to understand how their bodies changed throughout their lifetime.
Citation: Lida, X., O’Connor, J.K., McKellar, R.C., Chiappe, L.M., Li, G., Bai, M., 2017, A mid-Cretaceous enantiornithine (Aves) hatchling preserved in Burmese amber with unusual plumage