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I am going fossil hunting on some property I have in South Dakota this weekend. The Firesteel creek runs through it and I have found quite a few bison bones on quick 30 minute trips. This time I am spending 2 days along 1.5 miles of creek to look deeper If anyone has pro tips feel free to share

I'll break my trip report to South Dakota into two parts. First will be my visit to the BHI followed by collecting adventure The purpose of going to the BHI was to pick up the Leptoceratops maxilla's I left during my June trip. Pete has been collecting and pulling together specimens to understand and possibly describe this ceratopsid in the Hell Creek. The material he's collected so far appears to be from an adult and is much smaller than L. gracilis. My maxilla's seem to fit the smaller morphotype. In addition, the BHI provided me two sets of replicas of my specimens, pretty cool. Tankankaceratops is a controversial ceratopsian described by Ott and Larsen 2010. It's a small Triceratopsini known from a partial skull. Pete showed me its occipital condyle which is fused and indicative of an adult. Very cool nasal horn core. Here is a close up of Struthiomimus sedens hand/part of arm... the business end. Good reference photos A new addition to the museum is a cast of a juvenile Tarbosaurus skeleton that was being assembled in June trip Here is some White River material that was recently collected. Think Pete said the top left skull was a rare Camelidae Hespercyon Took photos for reference of the metatarsals from Nanotyrannus Another reference bone a Nanotyrannus carpal bone, much longer than any found on T rex.

I spent some time meandering through South Dakota in May, taking in the sprawling forests and mountains. It’s truly a beautiful area of the country with plenty to see and do. ^ Pareidolia clearly in full effect. Since I was in SD, I knew I had to pay a visit to the BHI - and if you happen to like fossils, I think you’ll enjoy tagging along. The BHI is a private company which specializes in producing cast replicas for museums and the general public. Until October 2020, they played host to the T. rex “Stan,” who was auctioned off for $32 million; it has recently been revealed that Stan is to be in a new museum in the UAE (whether Stan is privately owned or technically in a public trust in the museum I do not know, for those who wonder. In any case, at least he'll be enjoyed by the public). Besides Stan, the BHI is well-known for many other significant specimens including T. rex “Sue,” and Triceratops “Lane” (now displayed in the Field Museum in Illinois, and The Houston Museum of Nature and Science in Texas, respectively). I was looking forward to the visit since I have a couple of their casts, and I’d gotten a glimpse of the place through TFF. It was a rainy morning in the small town of Hill City; even without the sign, I knew I was at the right place. I entered through the gift shop and was immediately struck by the density of the awesomeness before me. My jaw didn’t leave the floor until I somehow convinced myself that I needed to go home. The BHI museum is in a small, one-room building that is packed top-to-bottom front-to-back with fossils. The center is a tight weave of dinosaur skeletons while the walls are lined with lighted cabinets. I was evidently the first visitor that day so I was able to enjoy the space undisturbed for a while. I normally don’t take so many pictures since I usually get lost in experiencing a new place, but I knew I was going to write about it, so I reminded myself to capture more. Some of them should also serve as good reference images (for me at least). (If you’re concerned about “spoiling” the experience for yourself, best get out now since this is pretty thorough.) So sit back and scroll as we take a short walk around the room… Some trace fossils An impressive Tylosaurus proriger from the Niobrara formation of Kansas, complete with sclerotic bones. “Big Al 2,” an Allosaurus (replica) A young Torosaurus skull (I believe part of the frill has been reconstructed) Anzu, pachycephalosaurus, T. rex Edmontosaurus annectens ... and an oddly-postured young Triceratops Sue's skull and a neat sculpture of the dig Denversaurus skull and armor Tarbosaurus skull (replica) Triceratops Smile! Towards the back is a display on the Western Interior Seaway, complete with Baculites and Xiphactinus.

Theropod skeletons from the Hell Creek Formation are very rare and avian ones are exceeding rare. Here the Black Hills Institute is putting together a replica of a partial Ornithomimosaur skeleton that was found with a complete undistorted skull. The skull and skeleton of this ornithomimosaur probably represent a new taxon according to the BHI. They state: that because this is the first skull from any member of the family Ornithomimosauridae from the Hell Creek Formation, it is impossible to compare it with other specimens. Clearly, however, the skeleton shows some features in the hand and pelvis that separate it from the described Struthiomimus sedens. Like my other BHI topics the photos and comments are from BHI President Pete Larsen. This replica is going to China. Started mounting an undescribed ornithomimosaur today for a Chinese museum. Using our copy in the background to speed up the process. Making progress on the cast of the undescribed ornithomimosaur from the Montana Hell Creek today. This is a very nice skeleton, despite the missing caudals and most of the dorsals More progress on the ornithomimid today. Finished mounting the other pelvic bones, dorsal and cervical vertebrae. Got a little bit done on the ornithomimosaur today. Finished mounting the chevrons and started on mounting the ribs. Mounted a bunch of bones on the ornithomimosaur today. One must be careful when you give a dinosaur a ribbing, because quite often they can be armed. Without complete feet it’s difficult for a dinosaur to move. I guess this ornithomimosaur will have to be toed We finished the ornithomimosaur mount today. Now we have to tear it down and make shipping brackets, readying it for the long painting process. This Hell Creek fossil is one of the great skeletons from the end of the age of dinosaurs. This is despite the fact that it is missing one leg and arm as well as its tail and most of the dorsal vertebrae Probably the most important part preserved is a complete and, for the most part, undistorted skull! One is not finished with mounting a dinosaur until shipping brackets are constructed to imobalize the parts inside a crate, and to be used should the skeleton be put into storage. We finished the mounting of the ornithomimosaur today

The BHI provides us interesting backstories into many of the replicas they assemble for museums or private individuals. I find this one fascinating and thought I would share it with the forum. Photos and writeup by Pete Larsen. Began putting together a cast skull of the Oklahoma Acrocanthosaurus atokensis. The right side of the skull is pretty much pathology free. The left side of the skull, however, is quite a different story. You will notice that the left nasal and nasal process of the premaxilla show damage. But the “killer” is what happened to the maxilla. Notice the extensive damage and active bacterial infection behind the 5th maxillary tooth. 7 alveoli lost the ability to grow new teeth! Maxillary Teeth missing A look at the medial aspect shows the closed alveoli and extensive osteomyelitis. And, in the center of the photo, the answers to “what happened" When we were cleaning the skull, a chunk of bone broke off the maxilla, revealing a tooth from a crocodile - as reported by Sam Elliot’s character in Pixar’s “The Good Dinosaur”! My comments: So it appears that this Acrocanthosaurus got his lower jaw bitten by a Croc, left a gift, a tooth which most likely led to the jaw infection which may have resulted in its death or at least severely affected its lifestyle. Interesting how many skeletons we see that have injuries. Life in the Cretaceous was not easy.

I've shown these before replica builds from the Black Hills Institute. This is a Gorgosaurus and all the commentary and photos are from Pete Larsen Begin mounting a cast of the Gorgosaurus nov. sp. the original is at The Childrens Museum of Indianapolis. This is one of my favorite Tyrannosaur skeletons. This one goes to Masashi Tanaka. Making progress on the Gorgosaurus skeleton. Every time I pickup a cast bone to mount I check to see if I missed any pathologies. This was one messed up dinosaur Finished mounting the vertebrae, looks like ribs are on for tomorrow. Did get a bit done on the Gorgosaurus ribs today, including putting steel in dorsal ribs 1&4 and the scapula-coracoids. Finished mounting the rest of the tail of the Gorgosaurus, adding the chevrons. One of the reasons this Gorgosaurus is such an awesome skeleton, is the painful plethora of healed injuries. The tail of this beast has a nice one. Notice that caudals 4 and 5 are fused. Looking more closely you can see that the common chevron is also fused to the vertebral centra. This is just the location one might expect to see a copulation injury. Add, yes, this is a robust individual (female). Just added the Ethmoid complex to the braincase of the Gorgosaurus. This is the perfect specimen to demonstrate what it is and where it is, because we are using a white brain-case. The ethmoid complex and the rest of the skull are poured in dark grey. Through the left orbit, you can see the dark ethmoid complex against the white polyurethane of the rest of the brain-case. Looking up at the roof of the skull, you can see the ethmoid complex and the portals that connect the olfactory loves to the rest of the brain. The olfactory lobe in tyrannosaurs presses against the frontals and is more than half the total volume of the brain.

For those of you that have visited the Black Hills Institute in Hill City SD you know that space is at a premium. When I heard that they were planning to add a replica of the large Jurassic Pliosaur Liopleurodon ferox , I said where? Well here it is flying high above. The new view as you enter Getting to this point was not easy. The replica was not complete and the skull was distorted. Started with a two meter skull mounting of the scapulae and the created coracoids positioned the pubes and ischia attached to the sacral ribs with a rod going through the “yet to be created” ilia attach the created gastralia basket, creating the disassemble circle that will support the massive paddles Mounting of the ribs Lots of modification to the ribs and lateral spines Its South Dakota cow country Bone corrections being made

Interested in seeing what it takes to put a replica T-rex of Stan together for a museum in Japan. Pete Larsen president of the Black Hills Institute walks us through a build through his Twitter feed. The mount starts in the hips, ilium and sacrum To mount the legs and pelvis (one operation) it takes 4 holders for the legs, 2 holders for the body and tail pipes, 1 welder and a spotter to see that it is anatomically sound Vertebrae added to the tail and getting longer. And longer... And longer Pubes, ischia and fibulae to the mount Gastralia are ready to mount on the skeleton Mounting the dorsal and cervical vertebrae, creating a fitting between cervical 9 and 10, so that the neck is a separate section. Ribs mounted Dorsal ribs 1 and 4 need steel inorder to support the pectoral girdle. Scapula-coracoids also need steel to connect to the ribs and support the arms. Finished mounting the chevrons Scapula-coracoids and the four supporting ribs mounted Those four ribs and the scalp-coracoids need implanted steel and fittings to support themselves and the arms, while still being removable for their shipment Arms added, installed the furcula Adjusted the Ribs Mounted the Crevical ribs Left Foot

The Black Hills Institute sells a number of replica of their Stan T rex specimen to museums and here are some images of one being put together. Dialogue mostly by Pete Larsen. This specimen will be hung and going into a very confined space. No idea who is their client. STAN is the largest, most complete, Tyrannosaurus rex, of the male (or gracile) morphotype, ever found. Finished mounting the skull, Stan T.rex skeleton. It is, indeed, the nicest T.rex skull. Finished the ribs, scapula, arms, and gastralia. If you were swallowed by a T.rex, and made it nearly to the end of the alimentary canal, and had x-ray vision, this is the the view you would see just before becoming a coprolite One of the common mistakes made by those of us who mount theropod dinosaur skeletons is to mount the scapula-coracoids as if they were the scapulae of mammals. This is the correct configuration. Not only do articulated specimens verify this hypothesis, but (in non avian theropods) the furcula must articulate with the scapulae. mounting the pelvis Here’s how you fit a 20+ foot long tail in a 10 foot space! Had to beef up the front post in the sacrum-ilia steel support, which will hold more than 60% of the total weight. Here you can see the supporting steel before we closed the mold and poured the polyurethane foaming resin. This cast skeleton will be hung, so we needed to add a skyhook between Dorsal 1 and Cervical 10 Ilia and Dorsals Here is the left side of Stan’s pelvis and left leg, laid out in preparation for mounting. This skeleton is going into a very tight spot that takes a lot of engineering to make everything fit and still provide a pleasing and anatomically correct pose.