DINO LAND PALEONTOLOGY INTERVIEWS
Among the common paleo questions such as "How did the dinosaurs die out?" and "Did they evolve into birds?" are the more deeply enticed questions, such as "Were dinosaurs social animals?" Nobody has taken more cracks at this question during the past two decades than University of Colorado paleontologist Martin Lockley. Lockley began his career as an Ordovician paleontologist, but soon became fascinated by dinosaur tracks. This fascination has led to a career that has, among other aspects, spanned from studying the only T. rex footprint to attempting to answer whether dinosaurs migrated to writing three popular books. This past summer I interviewed Dr. Lockley for my book project, and was amazed to learn so much about dinosaur social behavior and locomotion. Here are some of the highlights of my interview.
Steve Brusatte: Dr. Lockley, were you into dinosaurs or paleontology as a child?
Martin Lockley: No, I was not into dinosaurs at all. I was raised on a nature reserve and was always surrounded by animals. I became interested in paleontology when I got into college and a teacher passed along "the paleo bug" to me.
S.B.: In understand that you were raised in England. What colleges did you attend?
M.L.: I received my Bachelor's at Queens University in Belfast, Northern Ireland and my Doctorate at Birmingham University in England. I was raised in South Wales.
S.B.: Can you briefly trace your professional career?
M.L.: After college I took a post as a research associate in Glasgow, Scotland for four years. In 1980 I left for the University of Colorado, where I am now.
S.B.: You are known in paleontology circles as a dinosaur track expert. Exactly why did you decide to concentrate your career on tracks?
M.L.: Well, tracks of dinosaurs and other prehistoric animals give us evolutionary insights, especially those into the evolution of locomotion. Also, much of my work focuses on when particular groups reached a peak and became dominant. For example, I knew that Pterosaurs first appeared in the Late Triassic, but there was no track record of them until the Late Jurassic, which was when they became very abundant in the United States. This is also true with some dinosaurs. We know that they appeared earlier, but their tracks show their evolutionary peaks.
S.B.: I have read about your work on the only known Tyrannosaurus rex footprint. Can you briefly tell me about this?
M.L.: There is only one T. rex footprint known, which was found by U.S. geologist Chuck Pillmore. There were a couple of meters of rock beyond the track with nothing on it, which tells me that T. rex was probably moving about 6-7 miles per hour, which is a pretty good pace. I would compare it to a human's jogging pace. This would have been more than just a simple walk for T. rex, though. He would have had to have been walking real fast to go that speed!
S.B.: One of the classic T. rex debates is hunter vs. scavenger. Has this track given any new insights into the debate?
M.L.: The footprint doesn't tell me much, but my view is that it was probably both. I think that we are tending to ask the wrong question here. Look at the modern komodo dragon. It can eat pretty much anything alive, but will still eat a dead carcass. It's not fussy about what it is eating. The same was probably true about T. rex.
S.B.: I have read about T. rex as being a social animal, one that would travel in packs. What opinions do you have on this belief?
M.L.: In a general sense, larger animals tend to be a little more social than smaller ones. The bigger modern mammals, like wolves, tend to run in packs more than smaller animals, like mice. My guess is that T. rex was more likely to be a social animal because of the size than smaller carnivores.
S.B.: How about social behavior in other dinosaur species?
M.L.: Most of the large herbivorous dinosaurs, especially in the Cretaceous, like the hadrosaurs and iguanadontids, seemed to be social, judging on their tracksites. There are many track sites with 5-80 animals going in the same direction (80 is the "record"). This proves to me that some dinosaurs did travel in herds. Also, once again, it is interesting that the larger dinosaurs seemed to be social and the smaller ones did not. Look at birds today. Sparrows, a small bird, tend to stay on their own. Big birds, like geese and cranes, stick together in packs. The same goes with buffaloes, they are large and stay in herds. I don't know the reasons yet, some say that they may want to stick together to protect themselves from hunters, but I'm not sure about that. Maybe it's just a nature thing.
S.B.: Coupled with dinosaur social herding is the idea of dinosaur migration. This idea is supported by dinosaur finds in the poles, including Alaska and Antarctica. What views do you have on this idea?
M.L.: Once again, probably the larger ones spread out over big areas. If you look at the Morrison Formation in Colorado you see more or less the same animals over a large area. It looks like dinosaurs were moving around. The same goes with the dinosaurs in Alaska, they looked like they were going south (to warmer temperatures). I also must point out differences in size, again. Small animals don't get around much. A mouse can be born and live its whole life within 40 feet of its birth place. If you look at the larger animals you will find the smaller large ones (such as the gazelle) move around, but has a "home base" that it comes back to. It will travel 30-40 miles and will come back. The big animals like the buffalo will migrate 1000's of miles. There are a few exceptions to the big/small theory, with the most notable being migratory birds.
S.B.: There have also been reports of social hierarchy in dinosaur herds, especially those of sauropods and theropods. Does any of the footprint evidence prove or disprove this?
M.L.: It's a nice idea, but I don't think that the footprints prove it. I have a new book coming out this fall (The Eternal Trail from Perseus Books) that highlights my look for large animals protecting small ones. If you are looking for trackway evidence, though, it is hard to find. There are things that modern animals do that you can observe and compare to prehistoric animals, but the footprint record is another thing. You have to be very careful to say that footprints look like parents protecting their young. Bakker originally put this idea out because African elephants did it. I agree that it (parents protecting young) probably happened with sauropods, but once again, the footprint evidence has not been found yet. The same idea is true for the tracks in Glen Rose, Texas, where a carnivore is supposedly attacking a herbivore. I don't think the tracks prove it. You don't get this, a animal equivalent to the size of a hyena attacking an animal the equivalent to the size of a water buffalo on its own. They (scientists) are saying that one carnivore is attacking a brontosaur, which is 10-20X its size.
S.B.: I have read that you have done some research into dinosaur pathologies, especially limps. Can you briefly describe this?
M.L.: I noticed that there were quite a few trackways that looked like animals were limping. The classic evidence was a long step, short step, etc. These animals could have had a foot injury, or they could have been carrying something. In most cases, though, the foot itself looked normal. It (the injury) could have been in the hips, but I don't know why.
S.B.: After years of studying tracks, which dinosaur tracks would you say are the rarest, and which would you say are the most abundant?
M.L.: One group of dinosaurs that seem to be the rarest are the Stegosaurids. There have only been 1 or 2 tracks found. Then the armored dinosaurs (Anklyosaurids) and Ceratopsians. One possible explanation is that some of these animals may have preferred drier areas and did not want to walk around in muddy areas. Of course, the tracks we found are preserved in the mud. The most common type of track in the Jurassic are those of carnivorous dinosaurs. They are so common nobody has bothered to count how many formations they have been found in. Brontosaur tracks are a bit rarer than theropods, but are still abundant. There are 50 known localities containing brontosaur tracks. There are also 50 known track localities in Texas. 10-12 sites in Texas contain sauropod tracks, while 40 contain theropod tracks. Some groups of animals have tracks that are generally hard to find because they are small. Mammal tracks are hard to find in the Mesozoic because they were so small (of course, that changed through time). The same is true of some birds, too.
S.B.: What have been the largest and smallest prints you have come across?
M.L.: The largest single print I have found is a brontosaur track close to three feet (1 meter) long. The smallest dinosaur tracks I have found are of small, carnivores from the late Triassic. They were only 1-1.4 inches long, or the size of some bird tracks. Actually, they were smaller than pigeon tracks. They were way smaller than a chicken or turkey track.
S.B.: One last question before I let you go, what other areas of paleontology have you concentrated on except for tracks?
M.L.: From the time I finished my Bachelors degree I worked on Ordovician paleontology in Wales. There was a lot of field work, and I published a few papers on the subject.
S.B.: Thanks Dr. Lockley, and I will look for your new book.
M.L.: You're welcome, Steve.
**This interview will appear in a future episode of the Prehistoric Times.
© 1997 brusatte@theramp.net
Get your own Free Home Page