A short while ago I paid a rather unexpected and sudden visit to the AMNH in New York. American Museum of Natural History – that name stands for one of the greatest museums in the world, and it has much more to offer than just absolutely cool dinosaur galleries. But hey, I’m a dino researcher, so guess where I was headed 😉
Aside from being the first ‘big’ natural history museum I remember visiting at age 10 (I do not count the back-then small and cramped SMNS in Stuttgart; mucho has changed there since, including an additional building much bigger than the old one), the AMNH has been a special place for my own research career. It has, therefore, popped up here and there on this blog a few times. Well, many times. Very many times.
This time, I happened to have a flight back to Germany on a Monday evening, but learned after booking it that I would run out of work in Pennsylvania on Thursday evening. So the question was: change the flight, or make use of the time in NY? As not staying for one Saturday night in the US makes the flights become some $220 more expensive, and as the rescheduling fee was another $210, the decision was simple: stay in NY and try to get into the AMNH collections! Luckily, I know collection manager Carl Mehling pretty well by now, and luckily Carl is a really great guy. I posted a fun photo of him a while ago, and he’s still a big, knowledgeable, kind and funny bear of a man. I emailed him about my predicament of being stuck in NY, and sent along the required official letter requesting access – and got back a rather short email: “Sounds good to me Heinrich. See you soon.” Typical Carl 🙂
The AMNH’s Central Park entrance with Teddy Roosevelt on his horse.
Thus I found myself at the entrance punctually at 9:30 in the morning, ready to fill my camera’s memory card….. One of the things I hoped to achieve during this short visit was going back to the wonderful oviraptor specimens from Mongolia stored at the AMNH. I had photogrammetrized them during my last visit (see here and here), but because I was young an stupid I forgot to use a big scale bar. ‘big’ being important because when you scale the 3D model, the error of where you place your marker on the photo is pretty much the same, absolutely, however big or small your scale bar is. So a longer scale bar means that the error in each marker’s position becomes proportionally less! Thus, the accuracy overall goes up. So this time, I brought bigger scale bars, and was hoping to be able to take a few additional photos of each specimen, with the big scale bars draped around them.
Well, as those two samples show, I was able to access the specimens. Now I just had to find my old Photoscan project files, put the new photographs with the big scale bars into them, and re-scale. Here we go…… two scale bars of 50 cm each, and Photoscan calculates their errors as very slightly over 0.002 m (i.e., 2 mm!) each.
I also took photographs of the Edmontonia mount and the Protoceratops mount I digitized last time, for the same purpose. However, as they are encased in glass, I had to lean the scale bars against the glass on one side of the mount, then go around to the other side and take photographs from there. Any distance from the glass means there will be too many reflections. No idea if this will work out; I’ll let you know!
Obviously, I checked out a bunch of other things, too. Some of this I can’t write about right now, but you’ll be let in on the secret in a few months – promise! What I can say is that I spent a lot of time photogrammetrizing some of the many well preserved foot bones of Albertosaurus the AMNH keeps in the collection.
Bones like those in this drawer. I am always struck by a bit of institutional envy when I enter the AMNH main collections or the big bone room. Proper shelves and cabinets! A fairly flat and level floor! Our bone cellar has its own charm, with the wooden shelves and the brick floor, but for doing actual work in the room the AMNH is two leagues above us.