The World\'s Dinosaur Track Expert by Steve Brusatte
A portrait of Martin Lockley
by Steve Brusatte
Last month we looked at Karen Chin, the world\'s foremost expert on dinosaur coprolites, or fossilized dung. Before her it was David Weishampel, an established expert on European dinosaurs. Even further back in time was my portrait on Robert Bakker, most notably the earth\'s expert on Jurassic life. This month I will introduce you to the world\'s dinosaur track expert, Dr. Martin Lockley of the University of Colorado.
Since the beginnings of paleontology scientists have longed to find \"fossilized behavior.\" By trekking out to the American/Canadian west or Argentina, among other places, once can quickly and easily uncover traces of dinosaur bones. But, this bone cannot tell us how the dinosaurs breeded, hunted, or what their social life was like. That is nearly impossible. But, dinosaur tracks can. Dinosaur tracks are fossilized behavior, and Martin Lockley has made a career out of studying them.
Like most paleontologists, Lockley\'s beginnings were humble. As a youngster growing up in South Wales he was not interested in dinosaurs, but lived on a nature reserve and was constantly surrounded by animals. He entered Queens University in Belfast, Northern Ireland and it was there where Lockley caught the \"dinosaur bug\" from a professor. From that moment there was no looking back, as Lockley entered Birmingham University in England, received a Ph.D., and received a position as a research associate in Glasgow, Scotland. Lockley kept this job for four years, and in 1980 received a job as professorat the University of Colorado.
As a young college researcher Lockley worked on Ordovician paleontology in Wales, but later on he gradually switched research topics over to \"dinosaur tracks and traces\" (which one may recall as the title of his recent book). His job in the middle of prime track hunting country has only aided him in the quest to learn as much about dinosaur social behavior as he possibly can. And, after nearly 20 years of studying these tracks and the behavior they signify, Lockley has made quite a name for himself in the paleontological community.
Two years after he came to Colorado, in 1982, is when Lockley recalls that he became seriously interested in dinosaur tracks. \"I was interested in all aspects of the study of fossil prints, including dinosaurs and birds,\" he recalled his early days. \"More recently I have been working on pterosaur, mammal, and even Paleozoic tracks.\" According to Lockley, these Paleozoic tracks give us \"insights into the evolution of locomotion.\" But, since Dino Data is a dinosaur site we will focus on the major contributions he has made to dinosaur
One of the most frequently asked questions that Lockley receives regards his study of the only known Tyrannosaurus rex footprint. This print, found by Chuck Pillmore in the American west, has given numerous insights into the locomotion and speed of T. rex. \"It (the footprint) said that T. rex was probably moving about 6-7 miles per hour, which is a pretty good pace,\" Lockley stated, comparing the rex\'s speed to a human jogging. \"It was more than walking, it would have to be walking real fast to go at that speed.\" Some paleontologists have suggested that this one isolated footprint may solve the T. rex hunter/ scavenger debate. But, according to Lockley, it cannot. \"(In my opinion) it (T. rex) was probably both.
Look at the Komodo dragon. It can pretty much eat anything alive but will still eat dead carcasses.\" Regardless of his belief on the debate, Lockley does agree that this one track cannot give any insight into the question. After all, we must remember that it is only one mere isolated track, and the answers that it can give are very limited. Another frequently asked question is, was T. rex a social animal? Once again, Lockley says, this one small track cannot answer this debate. But, he said based on his knowledge of biology, \"in general sense, larger animals tend to be a little more social than smaller ones, bigger live mammals (wolves, etc.) tend to run in packs more than smaller animals. My guess is that T. rex was more likely to be a social animal because of its size rather than smaller carnivores.\"
Adding to the difficult question of T. rex\'s social life is the question of the social life of the sauropods, a common dinosaur type represented in the track record, and other dinosaur species. \"Most large herbivores, dinosaurs especially in the Cretaceous, like hadrosaurs and iguanadontids, seem to be social,\" Lockley told me, based on track site evidence. \"Many sites with 5-80 animals show that all of the animals are going in the same direction,\" he added, possibly suggesting herding.
Lockley also added to his theory on large and small animals. \"It\'s interesting, large animals seem to be social and small animals are not. Just watch birds. Sparrows (small birds) are usually on their own. Big birds like geese and cranes stick together in packs. The same goes with mice and buffalos. I don\'t know the reasons yet, some say they may want to stick together to protect from hunters. I\'m not sure about that, though. Maybe it\'s just a nature thing.\" One of paleontology\'s hottest topics regards the possibility of dinosaur migration. Since the discovery of dinosaurs in the polar reasons, Alaska, Australia, and
Antarctica among them, some scientists have reasoned that some dinosaur species may have seasonally migrated from the colder polar regions to warmer, middle latitude climate. According to Lockley, \"probably the large ones migrated. They (large dinosaurs) were spread out over big areas. Look at the Morrison Formation (in Colorado). You look over a large area and find more or less the same animals. It looks like dinosaurs were moving around. It looks like the same thing was going on in the Arctic Circle (and Alaska).\"
Lockley also believes that size plays a role in migration patterns, too. \"Small animals don\'t get around much. A mouse can be born and live its whole life within 40 feet of its birth place,\" he commented. \"The mid-sized animals, 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 larger animals like buffalo will migrate 1000\'s of miles.\" But, there are exceptions, he added, the key one being birds. Many species of birds, including very small ones, seasonally migrate to warmer climates yearly.
Claims of dinosaur \"social hierarchy\" have become synonymous with Lockley\'s findings regarding herding and migration. Is it possible that dinosaur herds had some sort of a \"leader?\" Is it possible that herds were arranged a certain way, with men on the outside and the mothers and children urrounded in the middle, possibly for protective purposes? \"Nice idea, but I don\'t think the footprints prove it,\" Lockley said.
\"There are things (such as hierarchy) that modern animals do that you can observe, but finding footprint evidence is another thing. You have to be careful to say footprints look like parents protecting their young. Bakker put the idea out because African elephants did it. He reasons that it probably happened with sauropods, but footprint evidence has not been found yet. It\'s a nice idea, probably true, but I am just guessing.\"
During my interview with Dr. Lockley last summer I posed an interesting question: what dinosaur tracks seem to be the most least abundant and why? Lockley gave an equally interesting answer. \"One group of dinosaurs that seem to be the rarest are the stegosaurids. Only 1 or 2 tracks have been found. One possible explanation is that some of these animals may have preferred drier areas and did not want to walk around in muddy areas.\"
In regards to the most abundant question, Lockley said, \"the most common type in the Jurassic is of carnivorous dinosaurs. They are so common that nobody has bothered to count how many formations they have been found in. They far outnumber sauropod tracks.\"
Lockley also described that some tracks are hard to find because of their size. Compared to a large, looming Tyrannosaurus rex track, a mammal track looks something like a grain of sand! \"Some groups of animals with tracks are hard to find because their tracks are so small. Mammal tracks are, and the same is true of some birds,\" he described. It is also interesting to note that the largest track Lockley has discovered was a Brontosaur print close to 3 feet (1 meter) long. The smallest were of carnivorous dinosaurs from the late Triassic, which were only 1 inch long, proving once again that the size of tracks does play a large role in their discovery! As you can see by some of his theories and beliefs, Martin Lockley of Colorado has revolutionized the field of paleontology.
The current dinosaur social revolution is due in a large part to him. And, don\'t think he is slowing down, either. Currently Lockley is studying a Bolivian tracksite (see the Dino Data eyewitness story). The social patterns, hierarchy, herding, migration, and even speed of animals dead 65 million years has been determined by Lockley.
It was once said that behavior can never fossilize. Judging by the tireless work of Martin Lockley, this statement is obviously false.