In our 24th episode of I Know Dino, we had the pleasure of speaking with Amaury Michel, the winner of our I Know Dino podcast giveaway in March, who has also been on two dinosaur digs: one in the Morrison Formation in Wyoming and one in the Prince Creek Formation in Alaska.
He was kind enough to share some pictures from his experiences:
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In this episode, we discuss:
- The dinosaur of the day: Carcharodontosaurus saharicus (Carcharodon is the group including the great white shark and megalodon) name was chosen because the teeth are sharp and serrated in a similar manner to the great white sharks, something that meant they could slice through the flesh of prey like sharp knives
- Originally described as Megalosaurus saharicus because as we mentioned before Megalosaurus was used as a “catch-all” taxon at the time.
- Because bones were destroyed during a bombing raid during WWII it hasn’t been as popular as T-Rex, but since the large skull was re-discovered in 1995, it is growing in popularity again (seen in several video games and the BBC series Planet Dinosaur)
- Carcharodontosaurus fossils were first published by Charles Depéret and J. Savornin in North Africa in 1927. Originally called Megalosaurus saharicus, its name was changed in 1931 by Ernst Stromer von Reichenbach.
- The Carcharodontosaurus is a large theropod dinosaur. These large dinosaurs typically walked on two legs (Theropoda is Greek for “beast feet”)
- Like Giganotosaurus it had 8-inch-long serrated teeth.
- It was about 13,000 pounds and was about 43 feet long probably slightly larger than T-rex. Also had a massive tail, a bulky body, and heavy bones. Its arms were short and had three-fingered hands with sharp claws.
- Closest common lineage to the T-rex is that they are both in the Tetanuran clade which started about 100my before Carcharodontosaurus.
- Carcharodontosaurus is often falsely dubbed the ‘African T-rex’, something which has misled many people into thinking that they are the same.
- Carcharodontosaurushas laterally compressed (flattened) teeth that slice through flesh. Tyrannosaurus in contrast has round conical teeth for crushing bone. Include other differences such as size and shape of the skull and overall body proportions, and it is clear that the two are completely unrelated.
- Paleontologists once thought that Carcharodontosaurus had the longest skull of any of the theropod dinosaurs. However, the premaxilla and quadrate bones were missing from the original African skull, which led to misinterpretion of its actual size by researchers. A more modest length of five feet, four inches.
- The Carcharodontosaurus lived during the Late Cretaceous Period (100-93mya).
- The Carcharodontosaurus most lived on what is now modern day northern Africa
- South America had likely just broken apart from Africa during that time, and it’s probably why Carcharodontosaurus and its relatives from South America are so alike in appearance. It’s environment was likely very warm and humid, with many rivers and lakes flowing through, considering Spinosaurus and Sarcosuchus (both aquatic/semi-aquatic predators) have been found in the same location.
- Although it was likely top-predator in the area, Carhcarodontosaurus was probably very territorial and had large areas of territory, which would likely have to fight for against rivals and other huge predators in the area, like Spinosaurus and Sarcosuchus, and even relatives like Sauroniops, Deltadromeus, and Bahariasaurus.
- The huge teeth were probably a key to the hunting strategy of Carcharodontosaurus. Carcharodontosaurus would probably create a massive open wound which would probably cause the animal to go into shock and disoriente it allowing Carcharodontosaurus to easily finish it off or just wait for it to bleed to death.
- Probably came into conflict with the largest carnivorous dinosaur of all time – Spinosaurus
- Carcharodontosaurus was a carnivore, with enormous jaws and long, serrated teeth up to eight inches long. It may have hunted in packs like its smaller cousin Allosaurus, but no fossil evidence of this exists. It may have been a scavenger as well as an active predator. It had a large head with over 60 8-inch (19 cm.), blade-like teeth, which were designed to pierce and tear apart the flesh of its prey, which mostly consisted of the large sauropod Paralititan and a hadrosaur called Ouranosaurus. It’s arms were somewhat short, but still longer than T. rex’s and still quite strong. They had three claws on each of its fingers, which could’ve been used to get a better grab on some of its smaller prey.
- Carcharodontosaurus had long, muscular legs, and fossilized trackways indicate that it could run about 20 miles per hour, although there is some controversy as to whether it actually did, because of its huge body mass.
- The smaller brain size of Carcharodontosaurus was probably pre-determined by its archosaurian ancestry as many theropods of its ancestral line also have similar brain sizes meaning that while their bodies grew bigger, the brains stayed the same bringing a halt to further biological development. The coelurosaurian dinosaurs however, the lineage that would include Tyrannosaurusand the transitional line to birds developed their brains away from the older archosaurian form allowing for the potential of greater reasoning.
- The inner ear anatomy of Carcharodontosaurus saharicus resembled modern crocodilians. The portion of the brain involving smell is quite large in Carhcarodontosaurus, suggesting a good sense of smell, probably even better than today’s dogs and rivaling the Tyrannosaurus.
- Fun fact:
For those who may prefer reading, see below for the full transcript of our interview with Amaury Michel:
Sabrina: So, how were you able to go on those two digs?
Amaury: The first one was actually a class trip. If you were taking the class, you were going on this day. It was with a professor of (? 0:10) course and I guess he just wanted to get everyone a background in Paleontology. The second one, he just asked me if I wanted to go on another dig. So I said, definitely, I am able to go on any other dig, yes.
Sabrina: So for people not familiar with the class or the professor, where did you attend school?
Amaury: I attended my undergrad at the University of Chicago and I took the Paleontology course the third quarter of my fourth year.
Sabrina: Now that you have taken this course and you have been on a couple of digs, has that influenced what you want to do, now that you have graduated?
Amaury: Oh yes, like 100%. I wish I had taken this course when I had started (volunteering and ? 00:51) because it is just like such a cool class. Even just like in-class volunteering is so fun because you get to…I don’t know, cleaning old bones is just really exciting, but it has definitely changed what I want to do. I actually had a job working in the Chicago schools before I got asked to go on the second dig. It kind of just changed everything that I was doing.
Sabrina: Can you talk a little about each of the digs that you went on?
Amaury: So the first dig was in Wyoming and we were working in the Morrison formation, right next to our (? 01:21) and after the sun rose we would have breakfast and then you are just working under the sun. The site was like…our professor had been there before. She knew generally where things were, so we were working at a site that had previously been worked at. In Alaska it was a lot different. We were working with shale and it was a lot wetter site. So we were on the North slope, working off a river. The shale was nowhere near as hard as the sandstone. So we would just hammer away at the shale and we would remove giant chunks at a time. Sometimes you could split up the shale and [02:00] just find bones in it and they were perfectly preserved. They were a lot smaller bones at that site.
Sabrina: What kind of bones did you find?
Amaury: So in Wyoming, I found a Camarasaurus rib and two Stegosaurus bones. We found a scapula and an ilium. In Alaska, it was just lots of Hadrosaur bones, tons of juvenile bones. We found some centenary parts, lots of femurs; hips and I found a few Troodon teeth. It was pretty exciting because you have all these Hadrosaurs and then you have a few, just Troodan, like some carnivorous teeth in the mix. So I don’t know what the story was there, but it was really exciting to find those.
Sabrina: So what do you do once you find the bones? How do you take care of them, get them out of the ground or the rock?
Amaury: So you find the bones and then you start making what are called ‘jackets.’ People use different methods, but as you clean the bone out of the ground, you will put consolident on it. Which is like a glue that will keep the bones together. So that when you are hammering on the ground next to it, it is a little stronger because a lot of these bones are pretty fragile. Once you have enough consolident on the bone, you will either, some people use aluminum foil and some people use toilet paper and they will put that over the bone, before you put burlap and plaster sheets over the bones. So you put tons of plaster and burlap over the aluminum, which is over the bone. So you keep surrounding the bone and you basically keep reinforcing it. You can’t just remove it right away, because it crushes; these things are millions of years old so you just keep digging around the bones. In some fields you will get a lot of bones overlapping each other, so it is really hard, but if you are lucky, you can just dig down and around the jacket that you have made of burlap and plaster and you just keep digging down and around it. [04:00] Eventually, when you get a comfortably safe distance from the bone, you start hammering under it or chiseling under it, whatever the case may be, it depends on the kind of bone that you are digging out of the ground and as you are doing this process, you keep jacketing the bone. So you keep reinforcing the bone and then when you are comfortable, you will flip it. Sometimes, you will probably want to do this with other people depending on how large the bone is. When you have a sufficiently large jacket over the bone, you will have a series of ulls under the bone, but it depends because some come out easier than others. Then you just flip it in some safe direction and you will expose an underside. It should mainly be just sandstone or shale or whatever rock you are working in, then you will jacket that in. Then in the lab, which is a more controlled environment, they will clean out all that excess rock that is around the bone, so that you can get a clean sample.
Sabrina: For your Camarasaurus bone that you found in Wyoming, how many people did it take to lift that up?
Amaury: So the Camarasaurus bone, two people worked on it, my friend Justin and I had been working on it. Then once we had finally jacketed it enough on it, which this one beautifully came out of the ground, it wanted to come out of the ground. It was just three of us just gently putting ulls under it and then we flipped it and it was just painless, but that was three of us that flipped that one. Then there were a lot of other really big jackets, like the Stegosaurus hipbones, that thing was over 1,000 lbs. So that took easily like six people to flip.
Sabrina: Did you have any training before you went on the digs, for how you deal with the bones or anything like that?
Amaury: That first dig, like I said, it was a class trip, so it was really that training exercise and it was not like we just got out there and started hamming away. On day one, a lot of things were being explained to us, but it was [06:00] just learned by doing. The second trip, I had some experience because I had gone to Wyoming, but the shale was so much different than the sandstone, but I had to also learn again, how are we going to work with this kind of rock? You can’t just use the same techniques everywhere.
Sabrina: Sure, could you elaborate a little bit on the different techniques that you used for both sites?
Amaury: Yes, in Wyoming, you just have to be a lot more patient with the sandstone. It is so hard; you just hammer down into the sandstone. You will have a pick and your geological hammer. So standard, anywhere that you are digging, you are going to have your hammer, your pick, some brushes and you are going to have some ulls. So for the Stegosaurus bones for example, those were really big bones, once we had the jacket around them, we were just hammering down into the ground. So most of our time wasn’t even hammering around the bone, it was just hammering down enough, so that we were able to flip this massive jacket. Whereas in Alaska, the bone that was way different because it was so dense, there were so many fossils. On day one, this site that had been previously established by Anthony Theorell and his teammates before, I guess he had a good idea that there were going to be bones, but once we showed up, on day one, I started finding all kinds of Hadrosaurus tailbones and vertebrae. The shale would come off in sheets. So you would hammer down in a clear surface and then you would be able to either pull a sheet out or a lot would come out at once. It was easier to dig into that than into the sandstone and it was also a lot wetter.
Sabrina: Was it a lot easier to spot a bone in the rock?
Amaury: I guess some sites are easier to spot bones. So in Wyoming, we got a lot of charcoal, which you can tell it is charcoal because you can just rub it with your finger [8:00] and it will just rub off, whereas a fossil will not rub off onto your finger. Again, you have to be careful when you are touching these things. I guess it depends what you are getting because some really small things are really hard to identify. In Wyoming, the bones were just a much different color than the sandstone. So if you were taking your time while you were going down into the sandstone, you would be able to see, okay this is a dinosaur bone, but in Alaska, we actually worked at two different sites and one was directly in the shale and it was pretty obvious what was bone and what wasn’t bone because the shale is very black and the bones didn’t have that same color. We also walked along next to this river, on this large bar of just rocks. We just spent one day just walking along these rocks and looking for bones that just washed up and that was a lot harder because you are basically searching and all over were just rocks, branches and all kinds of things and you are looking for mostly bone fragments. So that was a little harder, but I mean bones are porous, there are specific properties that bones have that you are not going to find in just a rock or a piece of wood. So even that wasn’t too hard to identify, I guess if you had seen a fossil or a bone before.
Sabrina: So what are some of the bone properties that you look for?
Amaury: So the first thing that you look for is the shape. So you know what bones generally look like. They are also sometimes very porous, so if you are looking down at a hip bone and it is missing part of it and you are looking not at the long part, but if you are looking at it horizontally, then you can see very fine pores. Other things that you look for, I guess some of our dredges are very obviously shaped, like this is not a rock, I can tell that this is from something that was living.
Sabrina: How long do these digs last?
Amaury: The first dig, I think we were out in the field about a week. We pulled a lot of jackets from the ground. Probably around 1,000 lbs. because some of them were so massive. The second one was longer; we were in the field for about two weeks.
Sabrina: What was day-to-day life like on the dig? Did you feel like you were prepared because I know that you have to go to a remote location and maybe it is really hot or maybe it is really cold, things like that, that need to be taken into consideration?
Amaury: So I think I definitely over prepared for both trips, but the second trip when I went to Alaska, it definitely took a lot more preparation because it wasn’t like a class field trip. There were a couple paleontologists, a geologist, and a bone preparer and we were going out to the site. So I wanted to bring a lot of my own tools, I had to bring my own everything basically. I wasn’t really prepared for a sun that never set. That was a very interesting part of that trip, the sun was just always in the sky, but the other trip that was in Wyoming was a lot more…here are all the tools and let’s just work, let’s learn how to extract bones from the ground.
Sabrina: When you were in Alaska, it must have been sometime during the summer, right?
Amaury: Yes, I was in Alaska in August, so towards the end of summer.
Sabrina: Since the sun is always up, do you just have to schedule, like okay with these X number of hours you are just going to have to sleep and force yourself to sleep?
Amaury: I don’t want to make it sound like it was directly overhead, it would kind of set, it was a little dimmer at night, but you could basically wake up naturally at any time. We weren’t fighting for daylight, then we would work for eight hours or whatever amount of work we needed to do in one day. It was actually really convenient because you could work at whatever hours you wanted to. If you started working later in the day that’s fine [12:00] because the sun wasn’t really going to set.
Sabrina: That is just what I was going to ask because you do need daylight to be able to do these digs; I know sometimes that can be a constraint so yes that had to have been pretty good to have that flexibility.
Amaury: Yes, it was nice. In Wyoming it was a lot more like…you want to work when the sun is out because you want to see everything, but also even though that was earlier in the summer, without the sun it just gets really cold because it is this dry heat so it doesn’t linger or anything.
Sabrina: Would you consider going on more digs now?
Amaury: Oh definitely. Since then, I currently have a job somewhere else, but I am just trying to read scientific papers, I am trying to read scientific books and I try to find a place where I can volunteer if I have that opportunity, but definitely I would go on a dig in a heart beat.
Sabrina: For people that haven’t had this experience yet, but maybe they want to go on a dig, how would you go about finding a place to volunteer, do you have any advice for that?
Amaury: Yes, if you are fortunate enough to live in a big city that has a museum that has fossils, try to volunteer. Obviously there is never any guarantee that you are going to go on a dig, but you are not going to go on a dig by not being around. So if you are at a university and you can take any courses related to paleontology or geology, just a huge array of things, take those classes, volunteer at fossil labs at your schools. You can also, if you are not fortunate enough to live by a big city or have access to fossils, you can look at surveys of land and find out what fossils might be around you and then you can just go out and see, oh this is this (? 13:37). Don’t take anything if you are not working with a group, but it is a good way to even get that experience for yourself. To say, okay this is the type of rock I am looking at, maybe there are fossils here.
Sabrina: Were you interested in dinosaurs before you took this class and even went on these digs?
Amaury: I was interested in dinosaurs, so yes I was interested as much as any science person is interested, I guess [14:00] because dinosaurs are awesome and it is a cool part in the story of life on Earth, but I wasn’t psyched about them. What I have come to realize with Paleontology is, a lot of people have been crazy about Paleontology since they were children, and they just never stopped being crazy about dinosaurs. Which is awesome because you have people that are super passionate about the subject through there whole lives. I kind of got into it in college.
Sabrina: What is your favorite dinosaur?
Amaury: My favorite dinosaur, oh man, there are so many cool ones. I think and maybe this will change soon, but I think my favorite dinosaur now is a carcharodontosaurus. It was massive first of all it was this crazy Theropod. It has really cool teeth, but also it has such a cool name…Carcharodontosaurus and then you just apply that name to this giant and I just think it is so cool.
Sabrina: Thank you so much for taking the time to speak with me today.
Amaury: Yes, no problem
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