In the fall of 2005 Kristi Curry Rogers, Curator of Paleontology at the Science Museum, answered questions about Titanosaurs and other Dinosaurs. This is the archive of those questions and answers.
Learn more about Kristi Curry Roger's research.
how do scientists know if they are real or fake because i found a bone in myyard and i am pretty sure it's a dino bone too
There are lots of ways to identify bones, and even more ways to identify fossil bones versus modern bones. Most of the time we can identify a bone by it's unusual shape (with lots of places to connect to other bones and muscles), by it's texture on the outside (smooth, but if you look under a magnifying glass, fine lines), and it's texture on the inside (lots of little holes where blood vessels, nerves, and cells reside when the bone is still alive). Rocks just don't have ALL those features, though they can sometimes seem to have one of them...like a strange shape. Modern and fossil bones usually differ in their density, and most of the time those holes on the insides of bones are filled in with minerals in fossil bones, and not in modern bones. There are exceptions to every rule, though. For example, the bones that we find in Madagascar are still as lightweight as modern bones, and don't always have minerals filling in the pore spaces of their interiors. It all depends on where and how the bones have been preserved! The best way to know is to spend lots of time looking at lots of bones, of modern animals, and fossil animals. In fact, most paleontologists spend as much time early in the educations working with modern bones as they do with fossils!
What is it like being a scientist?
Being a scientist is AWESOME! I love making discoveries, whether it is out in the field, or in a museum collection, or even in a laboratory. There is so much left for us to learn about dinosaurs, and I love being a part of the process. I also love to travel, and my research has taken me all over the world. I especially love being able to be outside for months at a time, camping, hiking, and searching for new things. It's the search for answers that really excites me.
Why did you choose Madagascar?
Our team began going to Madagascar not because of dinosaurs, but because of the really wierd LIVING animals on the island (like lemurs and chameleons). They are so bizarre that their closest relatives have remained a big mystery, and we went in search of some record of fossils that might tell us something more about what these bizarre, modern Madagascar animals came from. There isn't much of a recent fossil record in Madagascar, and when we ventured into older rocks there, we discovered an amazing ancient fauna that included dinosaurs! I joined the project as a graduate student specialized in the longnecked dinos, and got to work on all those great fossils from Madagascar.
Is it true that some scientists think that dinosaurs went extinct because of a huge asteroid colliding into Earth that created the Gulf of Mexico?
It is true that one of the hypotheses for the extinction of dinosaurs involves an impact event at the end of the Cretaceous Period (65 million years ago). Most dinosaur workers concur that this is probably a viable explanation, because there is a ton of geological evidence pointing that direction (including a crater in the Yucatan Peninsula, tsunami deposits in Texas, no real decrease in dinosaur diversity leading up to the event, etc). I'm not sure that we'll ever know for sure what did the dinos in, but it's important to remember that not ALL dinosaurs went extinct. The feathered ones that we know as birds are still around and doing great!
Are fossils of the Rapetosaurus only found in Madagascar? If not, where else have they been found? If not, why?
Rapetosaurus is only found in Madagascar, probably, in part, because Madagascar was fairly isolated at the end of the Cretaceous Period. Rapetosaurus does have incredibly close relatives, though - some of them live in India, and some in Asia.
Is your job all about dinosaurs or are there other things, too?
As the Curator of Paleontology at the Science Museum of Minnesota, I do a lot more than dinosaurs. All of my research is on dinosaurs, but I work with all kinds of fossils, from clams to giant sloths! I also do lots of public speaking, and teach classes at Macalester College.
is Allosaurus related to the Tyrannosaurus rex?
Yes, Allosaurus and T. rex are related to each other, but they are more like second cousins on the dinosaur family tree than grandfather and granddaughter. They both belong to the meat-eating group of dinosaurs known as Theropoda, but they have significant anatomical differences that make them more distant relatives.
is it true that we were once apes?
It is true that we share a common ancestry with other primates. Our ancient ancestry is a complex mosaic of evolutionary history, and we now know that there were lots of different early human-like animals that lived at the same time, and in the same environments as our early relatives. There are great websites on this question that you can access for more information, including the paleo portal - look online at www.becominghuman.org - a website at the Arizona State University's Institute for Human Origins.
how did you become interested studying dinosaurs?\r\n\r\nMaddy Moore
I was in love with fossils as a kid! I loved searching for fossils of all types, and where I grew up in southeast Missouri, the most common fossils I found were ancient marine creatures. In fact, my first fossil loves were trilobites! But, like a lot of kids, I had a thing for dinosaurs, and I never lost my interest. I went on my first dinosaur dig as a girl scout at age 16, and knew that I'd be hooked forever!
What dinosaur lived the longest?
The answer to this question depends on what you mean. If you mean AGE, the answer is, we just don't really know. We think that the big sauropods (the long-necked dinosaurs), and the big theropods (meat-eaters) probably had lifespans very similar to those of large mammals like us today. If you mean in a geological time-sense, the answer would have to be theropods, which are some of the first dinos that appear on the planet (225 million year ago) and are still around today, with their feathers on, in the form of modern birds.
IS IT COOL BEING A CURATOR OF PALEONTOLOGY AT THE SCIENCE MUSEUM?
Yes - I love being the Curator of Paleontology at the SMM. I have the chance to do so many things here, from research, to education, to mentoring kids, like me, who are interested in science. It's a wonderful job to have!
approximately how long does it take to uncover a dino bone in a cliff?
It can be quick or really long, depending on the size of the skeleton, the hardness of the rock, and the amount of overburden (the rock that lies on top of the skeleton). Usually we have 6-8 week field seasons in which we uncover multiple skeletons and completely remove them from the rock. They are encased in plaster and burlap jackets, and brought back to the museum where our preparators remove even more rock from inside the jacket, and clean and repair the fossil that it contains.
HEY HOW LONG HAVE YOU BEEN STUDYING DINOSAURS?
I've been studying and digging dinosaurs since I was about 17. I'm 31 now, so that makes it a whopping 14 years!
what sounds did the dinosaurs make?
We really don't have many clues about what kinds of sounds dinosaurs made. To answer these kinds of questions we have to look both at their anatomy (like the strange head ornamentation made up of the nose bones in duckbilled dinosaurs), and at the kinds of sounds that their modern relatives (crocodiles and birds) make. Their modern relatives make all sorts of interesting sounds, from hisses, to growls, to screeches and squawks. It is likely that dinosaurs had a similar diversity of vocalizations at their disposal.
Do you think that dinosaurs swam in the ocean? (T-rex's in particular)
Dinosaurs certainly didn't spend much of their time in the ocean — their bodies are built for living life on land. Who knows, though? We think that some dinosaurs may have had a taste for fish — maybe those dinos spent time at least wading in the ocean.
Are some dinosaurs related to birds, and some related to reptiles, or are they all one or the other?
ALL dinosaurs are more closely related to birds than to any other group of animals (including lizards, snakes, crocs, and other reptiles). One specialized group of dinosaurs, the meat-eating THEROPODS are actually the ancestors of living birds, so we can say that they share an even closer relationship with modern birds than other dinos do.
How do you find out how dinosaurs died?
Whether you mean "how did individual dinosaurs die" OR "how did dinosaurs go extinct" the answers to the question require sampling from lots of different types of data. We have to look at geology, and taphonomy (the science of how death and burial occur) in particular.
How acurate is carbon dating? I've read that carbon dating has been known to be very innacurate. What are your thoughts? Thanks.
Well, we can't actually use carbon dating on dino bones ÃƒÂ¢Ã¢â€šÂ¬" they're too old! Instead, we rely on other forms of radiometric dating (where unstable isotopes decay to more stable configurations at a regular rate) of igneous rocks that bound the sedimentary rock layers that contain dinosaurs. All forms of radiometric dating have a certain degree of error. Radiometric dating of rocks that include dinosaurs typically have a precision of +/- a few 100,000 years. Not bad, considering that dinosaurs roamed MILLIONS of years ago.
What is the name of the biggest dinosaur ever found?
The name of the biggest dino ever discovered is Argentinosaurus, a long necked plant eater found in Argentina. It's estimated to have been nearly 100 ft. long, and weighed almost as much as a blue whale (but it's only known from a few back and hip bones, so these estimates must be viewed cautiously).
How many dinosaurs have been discovered in Minnesota and where? Also what types?
None! The rocks that might preserve dinosaurs are really rare in Minnesota, and most of the time, they are marine (and dinos definitely didn't live in the ocean)
Do dinosaurs have gall or kidney stones which end up fossilizing?
As far as I know, there have never been gall or kidney stones discovered that can be linked to a dinosaur.
How do you know what color dinosaurs are?
We don't know for sure what color dinosaurs were. Just like for figuring out they might've sounded, the best approach that we have is to look to their modern relatives (crocs and birds) for input. I like to think that at least some dinosaurs might've been equipped with the wild colors of the cardinal, the toucan, the peacock, etc. But we'll probably never know for sure - color isn't fossilized!
How do you know where to look for dinosaurs?
We look at maps that tell us where rocks of the right age, that were laid down on land (by rivers, deserts, lakes, etc.). We also look for old reports, where early scientists describe their finds of dino bones, and revisit these old localities. You never know what you might find. In fact, this is why we ended up in Madagascar! Reports of a few dino bones found by a French scientist in the 1800s set us on the trail!
Is it ever a possiblity that the dinosaurs could ever come back through genetic reproduction? Thank you and have a great day!!
Certainly not with the technology we have right now. Most attempts to locate dinosaur DNA have been concentrated on bones (although bones have sometimes been completely replaced with minerals). Contamination is one worry. How do you know that any recovered DNA is from the dinosaur itself? Also, DNA is fragile stuff, much less stable than the proteins it codes for. Even in specimens much younger than dinosaurs, recovered DNA is usually broken into fragments.
In the movie Jurassic Park, the scientists used frog DNA as "filler" to fix the broken-up DNA. This isn't possible in the real world. And even if you could somehow recreate the entire dinosaur genome, you would need a living dinosaur egg cell to put the DNA into to create a clone.
We can clone a sheep right now because we have sheep egg cells, and living sheep to carry a cloned embryo to term. But paleontologists don't have dinosaur egg cells, or dinosaur surrogate mothers.
Incidentally, a few scientists think they might be able to find intact mammoth DNA (a little bit more likely) and raise the embryo in an elephant.
During what time period did the dinosaurs become extinct?
All dinosaur species were extinct by the end of the Cretaceous period, about 65 million years ago.
HOW MANY YEARS AGO DID THE DINOSAURS LIVE?
Dinosaurs lived between 230 and 65 million years ago, although no single species of dinosaur was around for that whole period of time.
What did the rapetosaurus eat to become up to 40,000 lbs? Thank you.
We aren't exactly sure what Rapetosaurus was eating. Even though we've searched high and low, there just aren't a lot of plan fossils. The most interesting thing about Rapetosaurus' diet is that it lived, unlike other long-necked dinosaurs, after flowering plants had evolved. Maybe Rapetosaurus dined on some of the first flowering plants! No matter what it was eating, it must've been eating pretty much all the time to maintain such high growth rates.
what happens to a dinosaur when it dies?
Usually, the same thing that happens to 99.9% of things that die: other organisms scavenge from it; heat, wind, and water weather it; and, eventually, bacteria and other microorganisms decompose it. A very few organisms, though, are preserved as fossils--remains or traces of ancient life. What conditions make fossilization more likely? 1) If a dinosaur were buried immediately after death, in mud or ash, for example, it might avoid the effects of scavengers, weathering, and decay. 2) If a dinosaur died in a place with little or no oxygen, like a stagnant lake bottom or a bog, then decomposers might not get at it. 3) Soft parts of organisms tend to get eaten by scavengers or decay rapidly. But bones, teeth, and shells can endure the elements longer and are much more common in the fossil record.
did dinos eat human beings?
Nope. Dinosaurs lived between 230 and 65 million years ago (although no single dinosaur species existed for all of that time). The oldest hominid, on the other hand, is only 4.4 million years old. And Homo sapiens, our species, is only 100,000 years old. So dinosaurs couldn't have eaten people--they didn't exist at the same time.
Aren't dinosaur names already decided for them? And if so, why do normal people pick the names out for them?
If you took high school General Science or Biology, you may remember that every plant or animal has a two-part Latin name according to the "binomial system." (The Swedish naturalist, Linnaeus, laid out the system in the 18th century.) Humans are Homo sapiens; wolves are Canis lupis; earthworms are Lumbricus terrestris, and so forth. The first name--or genus name--denotes the general kind of plant or animal it is. The second--or species name--denotes what particular kind it is. The Linnaean System is still in use today. And the Linnaean System lets the first person to describe a species give it its two Latin names. So if you find a dinosaur and it's a kind of dinosaur already known to science, then, yes, it already has a name and you have to use it. But if it's a new kind of dinosaur, and you're willing to do the work of describing it and having the description published in a scientific journal, then you get to name it.
How did Rapetosaurus krausei get its name? Curry Rogers says, "The Malagasy, or first people of Madagascar, tell of a mischievous giant named Rapeto (ruh-PAY-too), kind of like our Paul Bunyan. Saurus is Greek for lizard. And krausei recognizes my colleague, David W. Krause, for his contributions to paleontology as well as to the healthcare and education of kids in Madagascar."
Are all the dinosaur bones real ?
Are you asking about the dinosaur skeletons on display in the gallery? If so, the answer is, "It depends." The Triceratops is SMM's most complete mounted skeleton. It's about 85% real bones. Some skeletons are a combination of cast and fossil bones, such as our Allosaurus and the standing Camptosaurus. Some skeletons are complete reproductions, such as the Stegosaurus and the "dead" Camptosaurus. You can learn a lot by reading the skeleton's label: if the collections number is followed by a lower-case "c", then the object is a cast.
How do you know that the dinosaurs are put together correctly, with all the bones there and nothing in the wrong place?
We put dinosaurs together based on what we know about the anatomy of animals that have backbones. A lot of our work relies on studying modern animals, and we spend lots of time studying dino bones in detail. Usually there are special clues on bones (in the form of articular ends, muscle scars, etc.) that help us put things together correctly. Sometimes paleontologists make mistakes when they find something that is brand new, and occasionally we have to go back and revise our original thinking. That's part of what makes paleontology such a cool science of continual discovery!
Hi, my question is about your education. How long do you have to go to school to become a paleontologist?
I went to school for a LONG time (but not as long as some). I got my Bachelor's degree in Biology from Montana State University in the standard 4 years, and then went straight into a Ph. D. program at Stony Brook University in New York. I got my Ph. D 5 years later, in 2001, for a grand total of 9 years of post-high school education.
Why is it that reptiles evolved to become the dominant species during this era?
Reptiles didn't really evolve to "become dominant" during the Mesozoic Era. Pretty much all vertebrates living life on land and in the air and sea were "reptiles" in the evolutionary sense, because they all share a common ancestor. Technically speaking, even birds and humans are reptiles, cause we share an ancestor with other land-living vertebrates (and the first to be independent of water were reptiles.).
I heard a recent theory stating that dromeasaurs and other similar dinosaurs are actually flightless birds and that birds didn't evolve from dinosaurs but from a previous reptilian ancestor. What is your opinion?
I think that the evidence for the theropod (meat-eating dino) origin of birds is overwhelming. We now have evidence ranging from anatomy (did you know that meat-eating dinosaurs have wishbones --otherwise known as"furculae"), to feathers, and even to behavior (in the form of brooding and sleeping dinosaurs). To hypothesize that birds didn't evolve from dinosaurs requires a lot of convergent evolution, and results in a very complicated view of the bird family tree. Evolutionary biologists often use the principle of parsimony (basically, the simplest answer is best) for these kinds of complicated, historical questions. In the case of the idea that birds might not be derived theropod dinosaurs, the hypothesis is extremely UNparsimonious. I view birds as meat eating dinosaurs with feathers on.
What would be on your "Most Wanted" list - if you could find any fossil to help solve a scientific puzzle, what would it be?
I'd love to find more titanosaur bones - their evolutionary history is my own personal research puzzle, and until more specimens are found, some of the most interesting parts of this puzzle are still pretty mysterious.
How old are flowers? I mean, when did flowering plants first originate? Is there reason to believe flowers existed before that earliest fossil?
The origin of flowering plants is still a big mystery to us because we just don't have a great fossil record for the earliest flowering plants. The earliest fossils are known from Albian (mid-Cretaceous) time, and we assume that there is an extensive time for which we just don't have fossils preserved. One scientist that studies angiosperm evolution things that the earliest flowers might have lived in environments that aren't conducive to preservation (like dry, uplands), and just didn't make it into the fossil record.
How do you know what sex a dinosaur is from the bones recovered?
We actually don't know what sex a dinosaur is from it's bones. There has only been one possible discovery of a bone that could be sexed - Mary Schweitzer described a strange kind of bone tissue that she could see under a microscope. It looked kindof like the kind of bone that is deposited when female birds mobilize the calcium in their bones when they are laying eggs. This type of bone is called medullary bone. Other than that, we just can't know for sure. Even if we find dinosaurs sitting on nests of eggs (which we have in Mongolia and China), there's no way to know for sure that the sitting dino is a female.
if there ever was a dinosaur found is there a alert made or what would happen have ppl thouhgt about it??
Oh, I'm pretty sure that if live dinosaur were discovered, and its existence could be proven, you'd hear about it. It would be front-page news. Just look at the hoopla surrounding the rediscovery of the Ivory-billed woodpecker, a species that had "only" been missing for sixty years or so...
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