so if we use the declaration as our guide, i think the future is bright enough. i will stop there. [applause] >> you are watching american history tv. all weekend, every weekend, on c-span3. continues withan a visit to the museum of the rockies, where will we see some dinosaur fossil discoveries made in montana. placetana is a wonderful for discovery of dinosaur fossils not only because of the rocks we have and are present in the state but also because they are exposed. in almost the entire eastern portion of the state is exposed rock from the cretaceous time. , which preserved a lot of dinosaurs. the most famous formation for

dinosaurs preserves the last of the dinosaurs before they became extinct at the end of the mesozoic era. we have a lot of formation here in the state and that is where we go to find triceratops and t-rex. the first discovery of fossils in montana go back to the native american days. have been eroding out of these hillsides and crops forever. the first case of fossils being discovered were at the turn of the 20 -- turn-of-the-century in late 1900s -- late 1800s. a lot of those fossils went back to the east coast to large institutions like the carnegie,

or smithsonian. it wasn't until the late 70's that we found a site thanks to land owners that were rock one family found these fragments of baby dinosaur bones .nd dinosaur eggs shall not just babies but also nestlings that have been clearly cared for. the discovery of these eggs, adults, along with really changed what we thought about i -- about dinosaur behavior. this hall is called the halls of horns and teeth because it is focused on fossil from the help

creek-- the hell formation. formation is famous because of two types of dinosaurs in particular. that is triceratops, which is the horned dinosaur. teeth come from t-rex. the formation has produced a number of phenomenal tyrannosaurus rex specimens. t-rex is full of teeth and quite the fearsome predator. the dinosaur behind me does have a name. it's official specimen number is -- montana's t-rex was discovered on the fourth of july in the and

-- in the late 90's. when someone asks, why were you working on the fourth of july, i say, why would you think this is work? it was local ranchers who found montana's t-rex. is skeleton behind me here 60% real bone. it is very rare to find a t-rex or any dinosaur that is 100% complete. i don't think any of us would be complete after 66 million years of being in the ground. 60% real fossil bones

standing in front of you, really a rare and spectacular opportunity. the hornsobably see we havericeratops mounted as well. it is known for its iconic three horns. above the eye and a smaller one on the nose. it was likely to be a favorite prey item of t-rex. it is a vegetarian dinosaur that would have been looking out and trying to avoid t-rex as much as possible. crazy formation

-- right behind me is a triceratops growth theory. they are called triceratops because they have two horns about their eyes and one above their nose. most also one of the commonly found dinosaur in the formation. chains,look at food there are a lot more herbivores in the ecosystem than top predators. find a lot more triceratops bones than we do t-rex bones. the benefit of being such a commonly found dinosaurs we can see a lot about how triceratops grew and developed throughout its life.

see one of the smallest skull.tops as we continue down the growth see those start to horns above the eyes get bigger. and through their life and as they grow, they fused later and later. these are more fused, there horns are bigger and more curved. we continue on through getting closer to -- closer and closer to adulthood. we see the largest of our two.

some paleontologists believe this would have to do with .pecies recognition triceratopsof the also has the biggest curved downward curve horns, and what we see are these holes that develop. these holes would not have been holes in life. it is our paleontologist here who studies triceratops who believes the bone may have been deposited on these bigger horns .n their facial region about all of these

things, that this is an older triceratops and not a different species, is because of bone histology, and using histology to tell the age of individuals. histology is when you slice up an animal bone, and you slice it so thin that you can then put it on a slide and look at it under a microscope and look at the microscopic level of that bone and see things like cellular development that give things like an idea of these long extinct giants. choice ado we have a triceratops growth theory, we also have the largest tmax growth theory here.

here you can see the smallest scallop to ever be discovered. then we have another juvenile and younger t-rex. this one is also a replica. those are your younger t-rex is. in the paleo logical world there has been debate on whether that represents a different species or a juvenile t-rex. through histology, we are confident with our hypothesis -- that they juvenile -- they are juvenile t-rex's. with spectacular specimen an incredible story, largely due to the research of dr. mary schweitzer, a research associate here at the museum of the

rockies. her research found the oldest traces of soft tissue to be preserved in the fossil. an incredibly scientific specimen that has changed what we know about dinosaur soft tissue and dinosaur biology. as we rounded the corner we see larger and larger t-rex. this is the skull of the montana t-rex to see up close and personal. oldestond largest, our or-555.g to be m of the the centerpiece smithsonian's deep time exhibit.

and then the largest of our t-rex growth theory is one of the largest t-rex goals to be discovered ever. than five feet in length and would have been huge. it is much larger than the skull of montana's t-rex. the rest of the skeleton would have been much larger than what you see here. very few museums have an opportunity to see so many actual t-rex specimens in one exhibit. that is one of the highlights of coming to the museum of the rockies.

here we are at the bowman dinosaur viewing laboratory. this gives visitors an opportunity to see and work onst fossils right in front of them. our volunteers can explain to visitors how we find fossils in the field, how we get them out of the field, how we give them -- get them back to the museum. variety of a different dinosaur bones that are being prepared here in view for our visitors to see. femurs the triceratops still in the works. it needs to be consolidated. jacket, in its field which is made out of plaster and burlap.

next to it we have a triceratops vertebra. this is an individual backbone. it is fairly well together, but it looks like some of the spines need to be glued back together as well. we have additional vertebra from triceratops as well as other material. we have one of our volunteers. levi, how long have you been a volunteer here. over 5000 hours have volunteered and donated to be here in the viewing lab. these are actually the teeth

they grow in a dental battery. levi is very skilled at putting them all back together. we want to show how prepared we to share the process of paleontology with our visitors. >> i think it's extremely important to have small regional as opposed to the large one. they preserve our nation's history. it's extremely important to have these local museums such as museum of the rockies to give back to our communities. it brings montana to the world in the world to montana. staff travel tour

to bozeman montana to learn more about its rich history. to watch video from bozeman and other stops, visit c-span.org/cities tour. you are watching american history tv, all weekend every weekend on c-span3. >> next, nixon admitted ray -- administration officials describe events in the white house in the days before the apollo 11 moon landing. we hear from two former presidential aides who were in the oval office when president nixon placed a call to astronauts neil armstrong and buzz aldrin, who were on the moon. nixon foundation cohosted this event for the moon landing's 50th anniversary. >> good evening, ladies and gentlemen. as people continue to wander in, we are going to get started because we have a hard queue at 8:48.