Ask a Dinosaur Expert
Dinosaur Expert Sue Hendrickson

How did your interest in archaeology start?
I do two types of jobs. I am a marine archaeologist and a field paleontologist. I have been a professional diver for 30 years, and started working on aging shipwrecks many years ago. And 25 years ago on a diving trip in the Dominican Republic, I went to the amber mines and discovered fossil insects in amber. That's what started me working on fossils, or paleontology. And years later, I started working on big fossils when I started working on dinosaurs, instead of insects. As a marine archaeologist, I do archaeology underwater. As a field paleontologist, I look for, find, and excavate fossils, like dinosaurs.
What did it feel like to find Sue?
Unbelievable!!!!!!!!!! It's been 11 years and I still do not believe it! It's like winning the lottery 50 million times! I have found thousands of pieces of common dinosaurs, never in my wildest dreams, could I ever have expected to find a whole T. rex. You just don't ever find them, but I did. And I will never believe it! It's awesome! I'm so lucky.
Was it scary seeing Sue's teeth?
No, I love her teeth. She really has big teeth. I really want to see T. rex alive because I feel like she wouldn't eat me. Her teeth are very impressive and my biggest dream would be to see T. rex alive and have her be friendly. I don't want to be lunch!
Do you think there are anymore T. rexes like Sue?
I hope so. In 1900, the first T. rex was found. In 1990, Sue was the 11th T. rex. Since then, 24 more T. rexes have been found. But when I say a T. rex, most are just one or two bones. There are only five, including Sue, that are over 40 percent complete, and Sue is more than 90 percent complete, which makes her truly extraordinary.

I hope with more people looking more will be found, and hopefully find others as complete as Sue — that's what we really need to scientifically study the specimens. I want you to go out looking — there might be one with your name on it!

All together, how many bones were there?
On Sue, we have approximately 300 bones, and that includes some that aren't mounted yet. Her belly ribs, called gastralia, eventually will be mounted. She has some missing bones — one foot and one hand — but we had the others, so we could cast them. The last 8 inches of her tail and a couple vertebrae were missing, and that was all. For scientific purposes, she was complete. She's the largest, most complete, and best preserved of any T. rex ever found.
What was the most fragile of Sue's bones?
Her bones were in excellent condition — most weren't even crushed. Normally, you have to put a lot of glue into bones so they don't fall apart. But with Sue, the vast majority of bones were in great shape. I think the hardest were some of her teeth that had fallen out of her jaw. We had to put a lot of glue in her teeth because they were very fragile. But compared with other dinosaur fossils, Sue was easy. With foot bones that were about one and a half feet long, I could just pick them up with no glue. I then put a plaster cast on them to make sure they were safely transported to the lab. But in the field, I was able to just pick it up — after 65 million years, she didn't need glue!
Where are dinosaur bones mostly found?
Bones are found all over the world, but to find them, they can't be covered with grass or trees, so you usually find them in deserts. There are many good concentrations in the western U.S., Alberta (in Canada), Mongolia, Argentina, central Africa, but you really find parts of many dinosaurs all over the world. Of-course, you have to see the bone to find it. They exist in places with trees and grass, but you can't see them. We don't have machines to find them. Only the human eye can find them.
How long did it take to dig up the bones?
Excavating Sue was very fast — 17 days. The reason it was so fast is she was buried under 30 feet of rock. It took us five days to remove the rock. But when we got to the bone layer, she was all there in one place, so we didn't have to go looking for bones. We just had to cut big chunks of rock with her bones into chunks we could put onto trailers. For example, the largest piece of Sue was her pelvis and skull, which was in one block — that was four tons! Because her bones were in such a small area,30 feet by 40 feet, it was a rapid excavation. But then, the preparation of the bones took four years. The cleaning took a team of more than 12 people four years in the prep lab. But Sue was the fastest excavation ever because she was bone to bone to bone. I have friends who excavated a T. rex last summer in five months, working with bulldozers. It was washed in a stream, and every 30 feet, they'd find one bone. And it's going into a cliff. They've found about 40 percent and the bones keep going into the cliff. They'll continue next summer.
What tools do paleontologists use to dig up artifacts and bones?
In paleontology, when you're taking down the big rocks, you use shovels and picks. When you get close to the bones, you use a rock hammer. When you get even closer, you use a digging knife, a medium-sized knife. And then down to a smaller knife, an ex-acto knife. Also something like a dental pick. You use a paintbrush to keep the area clean. You have to be careful to keep the rock away from the bone — you keep sweeping so you can see. You usually use glues to stabilize the bone. When you're taking the bone out of the ground, you use a plaster jacket to cover it, just like with a broken leg. Then, a very important part is writing down all of the information. Where it is found geographically? What geologic layer is it found in? How is the bone positioned or mapped in relation to any other bones? What direction are the bones lying (north/south or east/west)? Is the bone vertical or horizontal or dipped? You also have to collect samples of the rock around it looking for pollen or plant samples to help in dating it. So, you don't just take the bones, you collect all the info that comes with it. You take notes and pictures and video to document it.
How do you know which bone belongs where on the dinosaur?
Sometimes it's easy because it's one I've already found or recognized, and sometimes it's hard. Sometimes we need to go to books that show the bones of different species of dinosaurs, and we can usually identify it that way. But the bones that I think are the most fun are the ones we don't know what they are. Once a year we have a big paleontology conference, and all the dinosaur people come together, and often bring their "mystery bones" to share with everyone else. It's like Show and Tell. Using the collective experience of all the best dinosaur studiers, we try to unravel the mystery. That's what I love about paleontology, or the study of fossils, is that there is so much discovered nearly every year. And we're solving mysteries and changing ideas all the time. So, it's like being a sleuth — it's really exciting.
Was tyrannosaurus a predator or a scavenger?
I feel very sure, as do 99 percent of all dinosaur paleontologists, that T. rex was a predator. She's completely physically equipped to be a predator. But as all predators do, they will also scavenge when the opportunity arises. They won't turn down a free meal! As far as I know, only one paleontologist is arguing that T. rex was only a scavenger — that is Jack Horner. And dozens of other paleontologists disagree and believe that T. rex was a predator.
Are T. rex's arms too short to be able to hold an animal to kill and tear it apart?
Yes, we really do not know what T. rex's short arms were used for. She could not reach her mouth, she could not catch prey, she could not push herself up from the ground. But they were very strong. Sue's arms are as long as mine. But with one arm, she could lift 1,200 pounds. So they must have been useful, because they're so strong. But we don't know what they were used for. There is one theory that they were used as holders for mating. But that's the only thing that's been thought of and that's a fairly remote theory. I'm hoping that your generation of dinosaur paleontologists will discover what those little arms were used for. We haven't figured it out for 30 years.
Do you think dinosaurs are like birds or like big lizards?
The meat-eating dinosaurs (therapods) are direct ancestors of birds. So birds are living dinosaurs. We even think today that the meat-eating dinosaurs very likely all had feathers — even T. rex. This is a very new theory. We haven't found a T. rex with feathers yet, but we think when they hatched from their eggs, they probably had feathers to keep warm, not to fly. But as they grew larger, they no longer needed the feathers, so they probably lost them as they grew bigger. But maybe they kept a few for decoration for mating displays — to catch a mate. In China, they have found adult meat-eating dinosaurs that are 6 feet tall, completely covered with feathers. This is what leads us to believe that all meat-eating dinosaurs probably hatched with feathers. To keep the warm-blooded warm when they were little.
If birds are direct ancestors of dinosaurs, why are birds so tiny?
Through evolution, when dinosaurs became extinct, the descendants filled different niches in the environment. When the big dinosaurs died out, the mammals had a chance to slowly grow and also fill niches, so there was competition with the birds and the mammals. And this is what controls species size, who eats whom in the food chain. And when dinosaurs were alive, there were dinos that were the size of chickens as adults. They were tiny dinosaurs.
What do you think killed off the dinosaurs?
It's widely accepted — nearly fact — that a meteorite hit the earth approximately 65 million years ago. The crater was found seven years ago under the ocean near Yucatán, Mexico. When this meteorite hit the earth, it was big enough to cause a dust or cloud layer that changed the climate of the whole earth, not just the impact site. Probably only 2 or 3 degrees of temperature difference. And that killed not only all the dinosaurs, but also 60 percent of all life on earth and in the ocean.
What was the most dangerous expedition you ever went on?
In my underwater archaeology work, I've been on a number of dangerous deep-diving excavations. Mostly just because it's deep, it's much more dangerous. We have had accidents of divers who got the bends. We had one who had no air for nine minutes, but we brought him back to life. Working on big ships in storms, you have heavy equipment — many dangerous conditions. Another trip, when I worked in Peru excavating fossils it was in an area of active terrorists. One time we had flat tires at night in a tiny village, and drunk men — we thought they were terrorists, but they weren't — they helped us.
What's the most exciting place to search, underwater or in rocks on land, and why?
That's a very hard question because I love both. I think working underwater is slightly more comfortable, but more dangerous. Working in the deserts for fossils, it's really hot or really windy, so you're pretty uncomfortable, but the thrill of finding something special on land or underwater is equally special. The thrill of discovery, being the first person to ever see a dinosaur or a gold ring that somebody died wearing on a shipwreck, it's like a gift when you're the first person to see it. You have this direct connection to that animal or that artifact — you feel like it was waiting for you, truly. I feel like Sue waited 65 million years for me to find her, but I'm glad she did.
How many expeditions have you been on and what was your favorite one?
I've been on dozens of expeditions over 30 years, and I have to say five were my favorite. Finding Sue the T. rex; digging fossil whales, dolphins, and sharks in Peru in the desert (my favorite place to collect in the world because it combines my love of the ocean and fossils); a Spanish shipwreck in the Philippines called the San Diego that sank in 1600. It was so complete that I call it the "Sue" of shipwrecks. Napoleon's ship L'Orient, which Admiral Nelson sank in the Battle of the Nile in 1798; finding Cleopatra's palace underwater in Alexandria, Egypt; and this year, in 2001, my best year in Egypt ever — we're now excavating the city of Herakleion (the city of Hercules), which sank underwater in an earthquake about 300 years before Christ. We found the most spectacular artifacts ever found underwater in Egypt: 18-foot-tall pharaoh statues, statues of a queen, the god of the River Nile, shipwrecks, tiny gold earrings, coins — it was the best year ever in Egypt. Those will go on a museum tour in about four years.
What job do you prefer, archaeology or paleontology?
I love them both. What I love about both is finding things. I love the thrill when I find something new. I'm like a 4-year-old on an egg hunt — I just want to find stuff; I don't care if it's underwater or on land. I'm addicted to looking for and finding things. That's my true passion in life.
Do you often visit Sue at the field museum?
Yes! In fact, I'm in Chicago right now — I just spent four days with Sue. Some with children, some with teachers and librarians, some of whom slept overnight. The last two days I've been at the same museum where Sue is to see the Cleopatra exhibition. It's the only museum in America where you can see it — the Field Museum — and it's here in Chicago until March 2002. This exhibition was only shown at the British Museum, in Rome, and here in Chicago. One of the statues that we found in the submerged part of Alexandria is the son of Cleopatra and Julius Caesar. This is in the exhibition along with hundreds of other images and statues of Cleopatra, Mark Anthony, Julius Caesar, and Octavian.
Who or what inspired you to be in your field of study?
I think I was born this way! As a small child I was very, very shy. I grew up in Chicago, and I always looked down while walking and was always looking for stuff — but because I lived in a city, it was mostly money! I started collecting seashells when I was 5, and I was a voracious reader. So I think I was very lucky in that my love of reading helped me my whole life — I've loved different subjects, and I was always able to educate myself on those subjects by reading and by seeking out the world's leading experts on amber, paleontology, underwater archeology. So my curiosity, which is still very intense, overcame my shyness and drove me to search out the things that interest me.
Do you have another favorite fossil that you visit while you visit Sue?
While I visit Sue, my whole amber collection is also at the Field Museum, so I go visit it and try to sort it. I have thousands of insects in amber. I have almost no time to do it, but when I do, I love to sort. Looking inside a piece of amber is entering another world. The amber is 23 million years old, and you're looking at it through a microscope to that other world. It's like diving underwater, looking at a shipwreck, which is also a whole other world. And it's also like looking for dinosaurs out in the desert; you feel like you're out in their world. I love being transported to other worlds through these objects.
What is your favorite dinosaur movie and why?
I don't know if it's my favorite, but the Jurassic Park movies have been done very, very well. The animation of the dinosaurs is excellent. I love to watch the dinosaurs in the movies, because that's probably as close as I'll ever get to seeing one alive. They try very hard to get it correct. I also love Disney's dinosaur movie, and also the Discovery Channel series on dinosaurs. Today's animation is awesome. The moment in the first Jurassic Park when the paleontologist first sees the living dinosaurs, they were living my dream in the movie — it gave me goosebumps!
How is your dog?
Skywalker is fine. She's right by me right now and I'm petting her. She goes everywhere with me. She has over one and a half million airline miles. She lives on the ships with me when we're diving. She's been in Egypt, the Philippines, Europe, Cuba, South America — she goes everywhere. She is my best friend and the best ambassador — everyone loves her. When I found Sue, I had my previous dog, Gypsy, and she doesn't get enough credit!
What advice would you give to students who are interested in paleontology, archaeology, or a related field?
I would say the best thing is to do your studies in school, focus towards the sciences or archaeology or geology. You can join the Society of Historical Archaeology, which I think is based in Tucson, Arizona. They have newsletters, publications, and annual conferences. And in paleontology, there's the Paleontological Society, based out of Denver, I think, which has annual conferences and publications. Through these publications you can find out which field activities need volunteers. There are many scientists who need help from volunteers in the summer. It's a great way to try the fieldwork.
Do you have any inspiring words for future paleontologists?
What I've learned through my life, I've been the luckiest person I know — part of luck you make yourself. You can do anything you want, if you try really hard you have no limits, except the limits you put on yourself. But you are in control of your life . For almost everyone, you have to take the first step. I've been on so many great adventures and expeditions because I took that first step and I never regretted it — it was always wonderful. So, overcome any anxiety, and go do it!