Getting to Know Local Dinosaur Sites : St George Dinosaur Discovery Site at Johnson Farm

For our next entry in the Getting to Know Local Dinosaur site series, we were lucky enough to talk to Andrew Milner from the St. George Dinosaur Discovery Site at Johnson Farms. Located in St. George Utah (2180 East Riverside Drive, St. George, UT 84790). I personally had a blast on this interview, and hope you all enjoy it as much as I did!


OK, so I guess just the first question tell us you about yourself and what you do?


I’m Andrew Milner and I’m the city paleontologist and curator at the St George Dinosaur Discovery Site at Johnson Farm. I’ve been pretty much involved with the locality since it was first discovered, which was back in March of 2000. I was hired on as the city paleontologist in October of 2001.

I was actually born in England, and my parents loaded my brother and I up on the ship and brought us to Quebec in Eastern Canada , and moved to a town called Shawbridge. They had no idea that they were moving to a French province at the time, it was a big shocker and learning curve, but I ended up growing up in Quebec and it wasn’t very long after I moved that I became interested in paleontology. My aunt was coming to visit from England and we were walking on the trail near our house and we found these little brachiopod shells from the Ordovician, and I was running all over the place picking them up. I got back home after that walk and my brother gave me a book on prehistoric animals and on the cover that’s where I saw my first dinosaur. I became addicted and never gave it up. I’ve always been fascinated with nature and geology. I ended up becoming an avid fossil collector and mineral collector including shells and insects, my house was full of Natural History type stuff. Really my first love was geology and paleontology.

I ended up donating my Champlain Sea Collection of over 6000 specimens, which I started collecting at the age of 10 from the Ottawa area in Ontario, to the Canadian Museum of Nature in Ottawa through a guy named Richard Harrington, who worked on mammoths and things. Very soon afterward Dick hired me on. That was in 1988, I was hired on to basically catalog all the specimens that I donated, including going through old collections. My first start in paleontology was working on late Pleistocene fossils from eastern Canada, Sub-Arctic stuff. While I was working there I received a phone call from a guy named Desmond Collins who was the curator of invertebrate paleontology at the Royal Ontario Museum, and he invited me to come and work at the Burgess Shale in British Columbia with the Cambrian stuff. I ended up speaking to my boss Dick, and he ended up saying, “yep this is a chance of a lifetime, and so go for it.” I ended up working the Burgess Shale for five seasons. Eventually I went to Brock University, in eastern Canada in St. Catherine’s Ontario near Niagara Falls, and that’s where I got my undergraduate degree and in geology with a minor in biology. I started a master’s degree with my professor Steve Westcrop, and was working on trilobites at the time. Things fell through because he took a job at University of Oklahoma as the curator of the new paleontology museum there, so I was kind of stuck. My wife ended up picking up a job in Utah of all places, and as soon as she told me that I was like, “take it let’s go!”  I ended up moving to southern Utah, and then I ended up getting the job at the museum. I guess I kind of went about it the hard way. You know only getting an undergraduate degree again after all the time. Anyway, I didn’t get my master’s or my P.H.D. But I guess experience goes a long way.


That’s an interesting story that you were out working in the field before you went to school for it.

Yeah exactly yeah it was I was very fortunate in that respect I guess.

OK next question would you mind giving us a little history of the park? You said it was discovered 2000.


Yeah it was discovered by a man named Sheldon Johnson, a retired ophthalmologist. He discovered the site on February 26, 2000. Unfortunately, we lost Dr. Johnson earlier this year, he passed away at the age of 92. He and his wife, Laverna, were the kind of people who would take care of it, other people would have probably destroyed it, forgotten about it, and not worried about it. Dr. Johnson decided to preserve the site, and called Jim Kirkland, our state paleontologist.  Jim phoned me to come down and check out the site since I was so close. It’s a pretty amazing place! Not only the original tracks that were found, which had incredible detail. A lot of the footprints that we’re talking about are early Jurassic dinosaur tracks, in the very beginning of the early Jurassic. These included track types called the Eubrontes Grallator later, and the crocodylomorph footprints called Batrachophus. We also have the oldest record of anamethis tracks in the world, which are produced by small plant eating dinosaurs.

If it wasn’t for the development started across the road for the museum, we probably never would have likely discovered the locality and had a chance to see these beautiful natural past tracks, several of which preserve skin impressions. As a matter of fact, our site has the largest collection of skin impressions preserved on dinosaur tracks of any site in the world. We’ve got about 40 specimens so far, and the numbers are growing as we excavate more. We ended up discovering a total of 16 different track horizons and about 150 feet of rock. We’ve recorded and mapped well over 6000 tracks at the site. Also, we’ve discovered the largest collection of dinosaur swim tracks ever in the world, which also preserve incredible detail for us.

Swim tracks are formed by animals that are buoyed up in the water, basically floating and kicking their feet to swim. If they’re in shallow enough water, their toes strike the muddy bottom and they leave the sets of three symmetrical scrape marks with the middle longer toe leaving a much deeper and  longer groove in the two outer toes even slightly shorter trace and they taper off at each end. They are preserved in amazing detail, preserving cuticle detail at the ends of the claws, sometimes skin impressions and scale scratch lines along the edges of the toes. In 2004, we discovered a sitting trace of the meat eating dinosaur. At the time it was only one of seven known specimens in the world, and now there’s like ten or eleven of them. Ours, though, is unique because it preserves detailed hand impressions, and it also preserves the way the tail drags. Interestingly, the trackway preserves digit one impressions on the left foot but not on the right foot. Usually when you see a theropod track, you usually see digits two three and four with the three being longer, but in this case we see rare traits a digit one preserved on the left. We also discovered, in the upper part of what’s called the dinosaur in the Moenave formation, we’re talking rocks that are between 200 – 195 million years old, so kind of an

estimate. We discovered two plant localities, preserving three new species and two new genera of plants which are just unique to St. George. Mostly conifers but we also have horse tails, ferns and cycads. And then we discovered as they were excavating for the school across the road, hundreds and hundreds of fish fossils. Associated with the fish, we also discovered dinosaur remains. We know that we have a type of dinosaur that is closely related to Dilophasaurus but it’s not Dilophasaurus. So far we have a partial vertebra, a nice complete anterior dorsal vertebra, and a bunch of teeth as well.


I guess the next question is. Why do you think people are attracted to dinosaurs, specifically compared to stuff from the Ice Age or early mammals?


Well, when I was a kid just seeing these big scary animals, you know, with an impressive size and strange looking, I think it attracts kids both young and old. I’m in charge of the prep lab at the museum as well, so I train volunteers how to prep fossils and a lot of these people are adults and retirees. When they were kids, they were fascinated with dinosaurs and now they’re kind of living a dream by coming and preparing fossils and learning about paleontology.


What are some of the most common questions you get from visitors?


The most common question is “why are the dinosaur tracks sticking up off the rock?” Our site preserves a lot of natural casts of footprints, so you’ve got the animals, the dinosaurs, walking along stepping through all the soft clay-rich mud and leaving the skin impressions and things like that. What happens is the sand washed in and filled the footprints, and then, over millions of years of course, the sediments became compacted and lithified. When Sheldon Johnson came along with this track hoe and started to develop the property, he ripped up these large blocks of sandstone and noticed these dinosaur tracks sticking up off the rock surface. His first impression when he found the first track was “there’s a dinosaur in the rock and its foot is sticking out.” That is by far one of the most common questions. Basically, when we find these things, the less resistant rock, the mud stones and shale below, tends to break up and fall apart but the beautiful sand fills the natural casts and preserved them. That’s how most of our tracks appear, apart from the in-place tracks like that we have preserved inside the museum.

I guess another common one is, “how do you determine how old the tracks are, and what kind of animals produced them?” Looking at the shape of the footprints we’re able to take an educated guess at what kind of track, or what kind of animal may have produced those certain types of footprints. In terms of the age, of course, we must talk about the rock units that we’re finding them in and how they correlate based on index fossils, and if we’re lucky radiometric dates in terms of getting ages on the rocks.


Are all the materials at the site from the location or do you have some brought in?


We do have material that was brought in from other sites. When I started working in St George, there were around 250 paleo sites known in all of Washington County. Because Paleo was basically avoided in southwestern Utah for some reason, and because of the discovery by Sheldon Johnson, we’ve now recorded over 650 paleontological localities within Washington County. So basically because I showed up on the scene and started to do a lot of exploring, we’re discovering that the area is rich in fossils.  The Johnson farm was an alfalfa farm, but Dr. Johnson’s kids weren’t interested in farming, so he started selling off pieces of this property. He was leveling this hill where the museum is located, and that’s when he discovered the in-place tracks. Where you see the museum now is where the first blocks were discovered. We found the footprints in position, and started mapping them back in April 2000 with Martin Lockley and Jim Kirkland and several other people. The museum is built directly over an emplaced Track site. We’ve mapped over 1200 tracks on the surface. Of course, some of that is now gone, we had to move some of the tracks site to accommodate the museum walls and the parking lot. There are tracks that go underneath the parking lot, and of course as they started developing the property across the road, we now own the five and a half acres. The city St George owns the facility and all of the specimens, but across the road we discovered additional track surfaces and excavated some of those, so it’s the exact locality where everything was discovered. All within about a one kilometer square area, we discovered most of these sites. Basically St George is built over a huge fossil site.


What are some things the visitors can look forward to when they when they come down there?


I think our site name, when we first opened, was a little bit misleading. In the early years we weren’t doing quite well, I think people came in and they expected to see dinosaur skeletons all over the place, so I think that’s kind of the expectation. A lot of people when they come in don’t expect to see tracks. A lot of people really love the tracks when they come in, and start learning about them. Every year we’re trying to add new things. For the longest time, for example, people couldn’t go out and look at the in-place track site.  They couldn’t go onto it because it’s so fragile, so last year we built a walkway out over the track site, so now that with signage and now that it is well-lit we have this big mural around the around the walls where the walkway is. We do have some dinosaur skeletons and smaller animals. We try to get everything late Triassic, Early Jurassic related, although we have kind of pushed into the Cretaceous as well. We do pick up things on the way, I kind of think the word got out and people are coming there to see the tracks. Every year they come back, and when people come back they’re going, “oh wow I never saw this before!’ We’re now starting to talk about plans for a future, larger building. We’re hoping for a full size Natural History Museum on the five and a half acres across the road.


You did say you had a paleontology prep lab, what kind of work do they do there?


We’re not actually a repository for storage of collections yet, but we’re looking to apply for one. We don’t have a lot of collection space, so basically a lot of our volunteers back in the beginning were basically prepping tracks. Tracks are quite difficult to prepare, when you compare them to a lot of lot of large dinosaur bones. Knowing where to stop is often difficult, especially when you’re dealing with footprints that have skin impressions. A lot of our volunteers have become extremely skilled at it, in terms of preparing tracks, but I’ve also been doing a lot of work with all these other sites we’ve been discovering in the region. I’ve also started working with other paleontologists like Jim Kirkland, with Dr. Randy Irmis from the Natural History Museum in Salt Lake, and other paleontologists, and we’ve been doing a lot of work in the late Triassic. I’ve been working over in the Monticello/ Moab area, in the late Triassic, as well as in the St George area in the late Triassic, and we’ve made some pretty amazing discoveries. We’ve been collecting. In this one area within about a ten-mile square area, we discovered eleven phytosaurs skulls. We’ve also been collecting a lot of micro sites in the St George area, so that’s kind of one of my things that I’m good at. I’m training my volunteers how to do micro fossil preparation. They’re preparing fish fossils, and little dinosaur reptile pieces, as well as phytosaurs skulls and things like that. We know we are pretty versed in what we’re preparing, so we’ve been preparing a lot of specimens for other museums like the Utah Geological Survey, and the Natural History Museum in Salt Lake, the Museum of Northern Arizona in Flagstaff. Right now we’ve got about fifteen volunteers that prepped for us through the year. Jim Kirkland has stated that our museum is one of the one of the fastest processing sites, that’s in terms of fossil preparation. We get a lot of stuff done. Most of the material, though, that we collect out B.L.M. and state land goes back to the Natural History Museum in Salt Lake, so I have been working very closely with them, and especially Randy Irmis.

We’re also training our volunteers something called photogrammetry. We take computerized 3d Models through photographs, overlapping photographs by about a sixty-six percent overlap. We’ve been training some of our volunteers on how to do photogrammetry, and recording track sites, not only track block specimens.  We’re doing this not only at our museum, but also out in the field. We’re kind of learning through the help of other photogrammetry experts, so we can process photogrammetric  data to make these computerized 3D. Models. One of our volunteers started taking on micro fossil teeth, doing photogrammetry in three dimensions of these little tiny teeth. Earlier this year Mike and I published a paper on the process of doing photogrammetry of these little teeth through photo stacking.

At some sites in Utah and in the American Southwest, they’ve been using photogrammetry especially with the tracks and traces becoming a big and important topic. There are certain sites that decay out in nature, and this is a good way to permanently preserve them and share with colleagues and the public in terms of not only in the publication, but creating these P.D.F. files so people can go in and view the view the track site and even specimens. We did photogrammetry of the entire track site before we put the boardwalk over it. One of the things that we hope to do with the data created is to have interactive stations within the museum, so that the public can come and look at the track site in detail and learn a lot more about that particular track surface by using the photogrammetry.


And one last question. Every time I do an interview, I have to ask what is your favorite dinosaur?


That’s a real tough one. Have you ever had people go, “can it be something other than a dinosaur?” I love phytosaurs, they aren’t dinosaurs, but they’re cool animals. I’ve become very interested in finding so many of them. I’d have to say that my favorite dinosaur at the moment has got to be Dilophasaurus. I love theropods, you know, the big meat eaters, the little meat eaters, they are all so cool. I imagine it will be my favorite until we find the rest of this dinosaur we found. I guess that one I get kind of happy about. The site that I discovered is called Andrew’s Site Cedar Mountain formation. Andrew McDonald and Jim Kirkland and others, including myself, co-authored because of the discovery we made at the site is a dinosaur called Hippodraco scutodens, which is on exhibit at the Natural History Museum in Salt Lake. It’s an Iguanadon dinosaur that I was involved with.


I hope you all enjoined the interview, and I highly suggest everyone make this a top stop when in the area! I loved my visit and cannot wait to go back!

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