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Questions from Students

A couple of weeks ago, I visited Dodd Elementary in Little Rock. After I left, the students wanted more information and sent me several questions. I thought, rather than respond to them individually, I would post the answers here.

Did saber-toothed tigers live at the same time as mammoths in the Ice Age? How old are mammoths?

Yes, they did! They even lived together in Arkansas during the Ice Ages, along with the more commonly found mastodons (which were like the mammoths, but a bit smaller (about the size of modern elephants) and were more adapted for forests than the grassy plains preferred by the mammoths.

What most people refer to as the Ice Age was in fact a series of almost a dozen times in which the glaciers expanded to cover much more land than they do now. This period lasted from about a million years ago to 11-12,000 years ago during what is called the Pleistocene Epoch.

There were actually many different species of saber-toothed cats. The most commonly known is one called Smilodon, which lived between 2,500.000  years ago to about 10-12,000 years ago.

The first mammoths appeared around 6,000,000 years ago, but the Woolly mammoths and the Columbian mammoths (the type that lived in Arkansas), first appeared about 400,000 years ago. They came south from Canada into the United States about 100,000 years ago. While they died out in North America almost 12,000 years ago, there were a few that lived on Wrangel Island near Russia until less than 5,000 years ago.

I wanted to know if cavemen were alive because didn’t the dinosaurs eat them?

All the dinosaurs (except birds) died out over 65,000,000 years ago, but the first humans only appeared around 200,000 years ago. So humans and dinosaurs were separated by an enormous amount of time and never lived together. Humans did live alongside the mammoths and saber-toothed cats during the Ice Ages, though. Humans killed and ate mammoths and humans and saber-toothed cats killed each other (we don’t know if humans ate the saber-toothed cats, but we’re pretty sure they ate us).

How old is coral?

Coral is very, very, old. The first corals appeared over 500,000,000 years ago. However, none of these early types of coral still exist. They all went extinct (died out) and were replaced by types of coral that evolved (descended) from them. The modern corals that you can see today first appeared in the Triassic Period roughly 200,000,000 years ago (the first dinosaurs appeared about 240,000,000 years ago).

How big is a T. rex egg?

No one knows! No T. rex eggs have ever been found. We can guess they were up to a foot long and up to five inches wide, but that is just a guess based on what we know of eggs that have been found from its distant relatives. What we do know is that T. rex babies were a lot smaller than the adults would have been no bigger than a small turkey.

How long is a sea spider?

fossil_focus_pycno_4Sea spiders, or pycnogonids (pic-no-go-nids), can grow up to 25 cm (10″). They can be found in the southern oceans today. Fossils of sea spiders are rare, but have been found as far back as the Cambrian Period almost 500,000,000 years ago. Even though they look something like spiders, while they are arthropods like spiders, they are not really spiders and occupy their own group within the arthropods. They are very strange animals, with most of their organs in their legs.

Eurypterus-remipes-LI think you may have been referring to a different animal though, the sea scorpions, which was part of the fossil collection we saw in class. Even though they are called scorpions, they are not true scorpions, although they are related to them. These animals, called eurypterids (your-ip-tur-ids), were mostly no more than 30 cm (12″), but could get almost 2.5 meters (8′), making them the biggest arthropods ever known. The earliest fossils we have found were dated at 467,000,000 years, but they may have first appeared over 500,000,000 years ago. They died out at the end of the Permian Period just over 250,000,000 years ago, along with most of the life on the planet at the time.

What is the shortest sea dinosaur?

While there were sea-going reptiles, there were no sea-going dinosaurs that we know of. The closest that we know of right now were the spinosaurs, which spent much of its time wading in relatively shallow water. These dinosaurs were huge, some of them approaching 15 m (50′) or more, with the smallest ones only a modest 8 m (26′).

Of the sea-going reptiles, the most common ones were the dolphin-shaped ichthyosaurs (ick-the-o-sores), the lizards called mosasaurs (literally lizard, they evolved from monitor lizards like the Komodo dragon),  the generally short-necked and big-headed pliosaurs (ply-o-sores), and the long-necked plesiosaurs (please-e-o-sores, for the purists, plesiosaur can also refer to both pliosaurs and the more traditional plesiosaurs because the larger group containing pliosaurs and plesiosaurs is named after the plesiosaurs. yes, it is a bit confusing). And of course we can’t forget the sea-going crocodiles called metriorhynchids (met-re-o-rine-kids).

The smallest ichthyosaur, or “fish-lizard” named Cartorhynchus (cart-0-rine-cuss) was less than 0.5 m (15″) long. it was also the oldest known one at almost 250,000,000 years old. You may notice that the picture below says the smallest was 70 cm, but an even smaller one was found.

Palaeontology_Ichthysaur

Dallasaurus (“Dallas lizard”), the earliest known mosasaur, was also the smallest mosasaur at no more than 1 m (3′).

The smallest plesiosaur was just over 1 m (3′).

Thalassiodracon, or “sea dragon”,  probably the smallest known and most primitive pliosaur, was 1.5-2 m (5-6.5′), so slightly bigger than its relatives, the plesiosaurs. All of the marine (sea-going) crocodilians were more than 2 m (6 ‘) and would have eaten the others, so we can rule them out for shortest marine reptile from the Mesozoic Era during the age of dinosaurs.

There is another group of marine reptiles that was also common during the Mesozoic, although they are not so widely known. The thallatosaurs, which literally means “ocean lizard” were as small as 1 m (3′). Finally, there was a sea turtle-like group called placodonts, of which the smallest were just under 1 m (3′).

Notice that most of them all start off at roughly 1 m, except for the ichthyosaurs, which started off at less than half of that, so the winner for shortest sea reptile of the dinosaur age is the ichthyosaur named Cartorhynchus.

What is the longest sea dinosaur?

The undisputed king of the marine reptiles was the ichthyosaur named Shonosaurus, also known as Shastasaurus, which reached 23 meters (75 feet).

shastasaurus-size

Still not the largest known individual of the species.

jurassicworld mosasaur

Jurassic World mosasaur, still not as big as Shonisasaurus

The longest mosasaur is, coincidentally, Mosasaurus itself, potentially reaching lengths of 18 meters (59 feet), so not as big as Shonosaurus. This animal used to live in Arkansas. According to the most official statements, the mosasaur in Jurassic World was 22 meters (72 feet), so bigger than the real ones, but not by a terribly large degree, and still smaller than Shonisaurus.

The longest pliosaur was no more than 18 meters (59 feet), while the longest plesiosaur was no more than 15 meters (49 feet), so none of them come close.

 

How did they breathe underwater?

It does seem like animals who live in the sea should be able to breathe underwater, doesn’t it? But the aquatic (a fancy word for living in the water) reptiles didn’t. Like all reptiles, they had to come up to the surface to breathe. This is true for any reptile that swims in the ocean, including sea turtles and marine iguanas. The same is true for their distant relatives, the birds. Penguins have to breathe air, even though they can dive deep. It is also true for all mammals, such as whales and dolphins. So how do they dive underwater and stay underwater for so long? They hold their breath, just like we do when we swim. Only they are much better at it than we are and can hold their breathe for a long time.

What is the longest land dinosaur?

That is an excellent question. The problem is that we have no fully complete skeletons of the largest dinosaurs, so we have to estimate their sizes from the bones we have.

Longest_dinosaurs_Scott_Hartman_Ken_Carpenter_Steveoc_86_Dinoguy2_700

As you can see on the chart above, there are several dinosaurs that are similar sized. Diplodocus and Supersaurus got up to 33.5 meters (110 feet). Argentinosaurus got upwards of 35 meters (115 feet) or more. Bruhathkayosaurus (Bru-hath-kay-o-sore-us) was possibly around this size as well, but the fossil material is too little to get a good estimate and what we had has disappeared. However, the American Museum of Natural History in New York has recently put on display the largest dinosaur ever displayed and possibly the largest dinosaur ever known at over 37 meters (122 feet).It doesn’t even have a name yet and is just called the AMNH titanosaur. Of course, the biggest dinosaur ever found is so little known that it has become almost mythical. Amphicoelias has been estimated to have been  as long as 58 meters (190 feet). Unfortunately, all that was found of this animal was a few bones, including a vertebra that stood 2.7 meters (8.9 feet) tall. The bones were very fragile, in very poor condition, and were preserved in mudstone, which crumbled easily. All of the fossils vanished (possibly crumbled away and swept out), so all we have left is a few drawings and measurements of the bones.

How big was Apatosaurus?

According to the fossils we have, Apatosaurus typically got around 22 meters (72 feet), but could have gotten as long as 27.5 meters (90 feet). Weight is a very difficult thing to estimate for many reasons, but most estimates place an adult Apatosaurus somewhere between 20-40 tons (40,000-80,000 pounds, 18000-36000 kg), or about the weight of 4-8 adult elephants.

apatosaurus-size

Illustratration by Darren Pepper, http://www.Prehistoric-Wildlife.com

What is the shortest land dinosaur? What is the smallest dinosaur?

Size_comparison_of_scansoriopterygid_dinosaurs

Illustration by Matthew Martyniuk. 1.8 m human, Yi qi (green), Epidexteryx hui (orange), Scansoriopteryx heilmanni (red)

That depends on what you consider a dinosaur. Anchiornis was estimated to be 34 cm (13″) long, but was a young adult, so probably got at least 38 cm (15″). But some consider Anchiornis to be an avialan, the earliest group of birds. Parvicursor is the smallest known adult dinosaur that is definitely not a bird according to some people, at 39 cm. Epidextipteryx was only 44 cm (17″) if you include the tail feathers, but only 25 cm(10″) if you don’t include them. However, Scansoriopteryx, also known as Epidendrosaurus, was only about 16 cm (6″), but we only have young ones that would have grown larger, but we don’t know how much larger. Epidextipteryx and Scansoriopteryx may look like birds, but were actually in a different group of dinosaurs. If you consider modern birds, the bee hummingbird takes the prize as the smallest known dinosaur at less than 6 cm (2.5″) and weighing less than 2 grams, just over the weight of a single penny.

But if you are talking about shortest, meaning how tall they stood, that is harder to work out because it would depend on how they stood, but none of these animals would have stood taller than 20cm (8″) at most.

For comparison, these dinosaurs were about the size of a common crow or perhaps even smaller.

Can an 8 feet tall person be as tall as a dinosaur?

A person standing 8 feet tall would be taller than a lot of dinosaurs. A baby just learning to walk would be bigger than some dinosaurs. If we include modern birds, which are also dinosaurs, there are some dinosaurs that a new born baby could hold in their hands (the bee hummingbird is less than 2.5″ long and more than an inch of that is taken up by the beak and tail feathers).

When did the dinosaurs live? When were they born?

nyasaurusmarkwitton

Nyasaurus, illustration by Mark Witton

The earliest known dinosaur is Nyasaurus, which was found in rocks thought to be 243,000,000 million years old during the Triassic Period, the first part of the Mesozoic Era. There is some uncertainty if this was an actual dinosaur, so if it wasn’t, that would make dinosaurs like Herrerosaurus and Eorapter (both of which looked similar to Nyasaurus) the oldest dinosaurs at about 230,000,000 years old.

When did the dinosaurs die?

Everything that most people call dinosaurs died out at the end of the Cretaceous Period, the third part of the Mesozoic Era, about 65,500,000 years ago. However, they didn’t all die out. One small group of dinosaurs survived, which are the birds. Today, birds are the most diverse group of terrestrial vertebrates (animals with a backbone living on land), so dinosaurs are alive and thriving.

How long did the dinosaurs live?

Dinosaurs were on earth for a very long time. From their beginnings over 240 million years ago to the end of the Cretaceous Period, they lived for around 175,000,000 years. If you include the birds, they have lived for over 240,000,000 years and are still going strong.

If you are talking about individual dinosaurs, they have varied lifespans. Just as you can find mammals that live no more than a year or so to mammals like us that can live over a hundred years old (the oldest known person lived to 122), you can find dinosaurs that lived like that. Some species of hummingbirds only live a few years, so we can expect that some other dinosaurs may have only lived a few years as well. The giant, long-necked sauropods were adults by their teens and may have lived as long or longer than we do. We reall

How old are T. rexes?

If you mean how long ago did they live, Tyrannosaurus rex lived at the very end of the Cretaceous Period, the last period of the Mesozoic Era, 68,000,000-65,500,000 years ago. If you wanted to know how old an individual T. rex could get, They did most of their growing when they were between 14-18 years old, reaching maturity between 16-18 years old. But they didn’t live long after that. All of them that we know of died before they were 30. Of course, whether or not they could have lived longer than that, we don’t know, but that is the ages of the fossils that we have.

How did the dinosaurs die?

Most of the dinosaurs died out at the end of the Cretaceous Period about 65,500,000 years ago when two major events happened. The first was eruption of one of the largest volcanic events in the history of the Earth. The volcanoes that formed the Deccan Traps in India were so massive, the rocks from the lava put out by these volcanoes are over 6000 feet deep. These eruptions happened over tens of thousands of years, maybe even millions of years.

But that wasn’t the worst thing. An asteroid hit in Mexico at the same time as the volcanic eruptions were taking place. It was estimated to be about 10 kilometers (6 miles) across and left a crater more than 100 miles across. Remnants of the crater can still be seen in Chicxulub, Mexico. If all the nuclear bombs in the world were exploded at the same time, it would not be as powerful as the impact of that asteroid.

Did some animals live after the volcano and meteor?

Amazingly enough, yes. If they had not, we would not be here. Every form of animal suffered heavy losses, but most did not die out completely. One small group of dinosaurs survived, which became the birds. A lot of mammals died out, but a lot also survived. Amphibians and crocodilians did reasonably well. Anything small, able to take shelter, and lie dormant (like squirrels hibernating in the winter) to conserve their energy and ride out the tough times did ok. In the oceans, anything large, needing a lot of food, or having shells had a hard time.All the large sea-going reptiles died out. Virtually all the shelled cephalopods (squid relatives) went extinct, but their unshelled relatives survived. Tiny organisms called plankton that lived in the ocean and made their shells out of calcium carbonate died out and were replaced by types that used silicon for shells. During the Cretaceous, the ones with carbonate shells were so common, when they died, their shells piled up and became huge layers of chalk, forming what became the famous White Cliffs of Dover in England and the chalk beds in southwestern Arkansas, among other places. But they almost all died out during the volcano and meteor impact and never became nearly as abundant ever again. The reason for this is because the asteroid and volcanoes released so much carbon dioxide and sulfur into the air that was soaked up by the oceans that the oceans became very acidic and lost a lot of oxygen. So anim

Of course, insects of all sorts survived, as did a variety of invertebrate animals like snails, clams, starfish and the like. But all of them took severe losses, especially those that were specialized to eat only certain plants or animals. One that had a more varied diet managed to survive.

How was it there? Was it dusty or cold there?

During the Mesozoic Era, the time of the dinosaurs, it was, in general, warmer than it is now and the temperature differences between seasons were not as extreme as today. The north and south poles were not permanently frozen over during this time like they are now. But much like today, there were all types of weather and environments. It was hot and dry in some places, it snowed in other places. There were swamps and prairies, forests, deserts, almost any environment you can think of existed then. The only environment you might not find would be glaciers, but you could probably even find them near the tops of mountains at times. Of course, they didn’t exist in the same place on earth and there were different dinosaurs that lived in different areas.

Also remember that the Mesozoic covered an immense span of time, so the earth changed during this time.

Why didn’t the dinosaurs need to fly?

Some dinosaurs did fly, but most didn’t. Most animals today don’t fly either. I expect most animals would if they could, but it takes a lot of changes to evolve the ability to fly. As animals evolve, they can’t decide they are going to develop flight. Small changes will appear in individuals from time to time and if those changes are helpful (or at least not harmful), then they get passed on and can spread through the population. To develop flight, a large number of changes have to happen, so only a few types of animals have evolved in the right way to develop flight. Once they did though, it was very effective, which we can tell by looking at the large number of birds and insects and even bats that can fly.

Is it true that fish had sting rays?

Southern-stingray-dorsal-viewThere are some fish called stingrays and they do indeed have venomous spines on the tail, which can be painful and occasionally deadly if they sting someone. They only use them in self defense though, so they won’t hurt anyone unless they feel threatened.

Stingrays are common today and can be seen in many aquariums. But they are also found as fossils and have been around for millions of years. We have even found fossils of stingrays in Arkansas. They do not have bones like we do, but we do find lots of their teeth, which look like flat rectangles. They use these flat teeth for crushing shells of clams and other animals.

What was the tiny thing at the bottom of the smart board?

I’m sorry, I don’t know what you are referring to. Was it on the timeline? Please let me know and we can figure it out.

How many bones have you found?

I have found lots of shells and crinoids. I have found a handful of shark teeth. But I haven’t found too many bones. When I was on a dig in Argentina, I did find a pelvis (hip bones) of a sauropod (the giant, long-necked dinosaurs). I also found part of a skeleton of an archosauromorph (the ancestors of crocodiles and dinosaurs). When I worked in Wyoming and Colorado, I found several fossil turtle shells and part of the horn of what may have been a uintathere or some similar animal (rhino-like mammals with knobby horns and bumps on their heads). I also found several tiny bones of rat-sized mammals. I don’t know what they were, but I remember one place where the bones looked like turquoise (a greenish-blue gemstone).

What I would really like to find would be a dinosaur in southwestern Arkansas, although the skull of a mosasaur or elasmosaurus would be a close second. There are opportunities for finding fossils in most of the state, so keep looking and let me know if you find something!

Holiday Fun in Arkadelphia

Wow. I can not believe that I have not posted anything here since Halloween. My New Year’s Resolution is to not let that happen again. I have no excuses. But as was said on the Syfy show The Expanse, “We can not change the things we’ve done, but we can all change the things we do next.”

For this post, I want to relate the trip I took to Arkadelphia just before the Christmas holidays to visit the Goza Middle School on the invitation of one of their science teachers, Trent Smith. That trip will benefit many people in the future, and it also provided a chance to see some Arkansas geology and paleontology that may prove interesting to fossil enthusiasts.

The fossils that started this off. Picture by Trent Smith

The fossils that started this off. Picture by Trent Smith

This all started with an email I got from Trent Smith, who had found some fossils he wanted help identifying. After looking at the attached photo, I tentatively identified most of them as specimens of Exogyra ponderosa, a common oyster from the Cretaceous Period. There also appeared to be a goniatite ammonoid, a Cretaceous Period cephalopod, or squid relative. I could not be sure just from looking at the pictures, so I offered coming down to take a look at them in person. Trent was amenable to that and after a few emails back and forth, we arranged to not only look at his fossils, but talk to his eighth grade science class while I was there. It turned out that the school was interested in me talking to multiple classes, which all told was about 160 students. They suggested I could either give one talk to all of them at once, or I could do multiple talks to individual classes. I much prefer the smaller groups where people can get a more hands on experience with the fossils and have more opportunity for students to ask questions, so I opted to give several talks. I wound up giving seven talks, with two of the talks to combined classes. So I had the opportunity to speak with a lot of students.

When I got there, Trent helped me bring in my boxes and took me to his room to start setting up. Goza Middle School students are fortunate to have great science teachers who are passionate about science and education. Trent’s classroom fossil collection was by far the largest fossil collection I have ever seen in a public school classroom. They have a good variety of most of the invertebrate fossils that can be found in Arkansas. They also had a fabulous nautiloid ammonoid 4″ across or more. I had a shell of a modern Nautilus, a genus of the only extant ammonoids, so the students were able to compare a modern version with one over 70 million years old.

For each class, I gave a short introduction to the fossils that can be found in the state, which is much more diverse than most people realize. I also gave them a quick demonstration of the immense expanse of time we were discussing. I have a timeline that stretches eighteen feet and covers 600 million years. People are usually suitably impressed with that timeline, but when I tell them how much space our civilization represents on the timeline, they are stunned. At that scale, all of human recorded civilization is approximately the width of one human hair. Afterwards, we let the students look at the fossils I brought and ask questions. The students were more reluctant to get out of their seats and approach the front table than the younger kids I usually talk to, which I found interesting and speaks to how quickly we train our students to sit and listen without interaction. But once they got over their training, they enjoyed being able to handle the fossils and examine them close up. The students were uniformly polite and well behaved and were a pleasure to talk with. Midway through, the teachers treated me to a tasty potluck lunch.

My new favorite shirt

My new favorite shirt

If everything was left at that, it would have been a great trip and I would be happy to return, but they really went above and beyond. In addition to lunch and a small donation (I have generally not asked for payment for classroom visits in the past and as a result, getting paid for it almost never happens, but getting paid means I can go to more classes so is greatly appreciated), they provided me with even more. They gave me my first two Paleoaerie shirts, which they designed and they did a fantastic job. On the front of both shirts is a dinosaur foot that looks like the foot of Arkansaurus, the only dinosaur bones ever found in the state, and my name, Dr. Daniel. On the back of one shirt, it has the dinosaur foot with the words PALEONTOLOGY above it and DIGGING UP KNOWLEDGE below it. On the back of the second shirt, it says PALEOAERIE.ORG followed by my three statements of what guides my efforts: The universe is endlessly amazing, knowledge is useful only when it is shared, and you can’t really know something unless you understand how and why we think we know it. The shirts are going to be my uniform for future talks.

Exogyra ponderosa (Cretaceous oysters) collected in Arkadelphia by Trent Smith.

Exogyra ponderosa (Cretaceous oysters) collected in Arkadelphia by Trent Smith.

After school was over, Trent showed me a spot he has collected fossils from on Wp Malone Road, just west of I-30. According to the Arkansas Geological Survey’s geologic map of the Arkadelphia quadrangle, the area is listed as being in the Nacatah Sand, an Upper Cretaceous formation consisting of a mix of unconsolidated sediments deposited in a nearshore marine environment. However, the marl, a limey clay, we found in the creek looked more like it came from the Marlbrook Marl, a formation that lies underneath the Nacatah and separated from it by the Saratoga Chalk formation. The Saratoga Chalk is not thick in this area, so it is quite easy to go from the Nacatah to the Marlbrook in a very short distance. In this particular locale, the Marlbrook is close by and it is likely that what we found was washed downstream to where we found it. As I recall, Trent mentioned that fossils were more common the farther upstream one went, which would support this idea. The Marlbrook Marl, when fresh, is a blue-gray lime clay, or marl, laid down in nearshore, shallow marine environments, just like the Nacatah Sand, but without the sand contribution. The upper part of the Marlbrook is also famous for being extremely fossiliferous and this site was no exception. I initially attempted to collect what I found, but very quickly realized there were so many shells that it was impossible to carry them all. The great majority of what we found were shells of Exogyra ponderosa, but the numbers would have allowed us to quickly fill a crate with specimens. We also found a few snail shells (of what type I am not sure) and a terebratulid brachiopod, but the numbers of everything else did not begin to compare with the shells of Exogyra. On other trips, Trent collected numerous Exogyra shells and gave me two boxes full of shells. Thanks to him, I will be able to supply many Arkansas classrooms with actual Arkansas Cretaceous fossils.

Collection locality. Marlbrook (outlined teal-colored area) is upstream just west of collecting site.

Collection locality. Marlbrook (outlined teal-colored area) is upstream just west of collecting site. Click to enlarge.

Poorly preserved snails and clams. Little orignal material remains, leaving only the internal molds.

Poorly preserved snails and clams. Little orignal material remains, leaving only the internal molds.

This area is a nice place to collect. As long as one is on public land (or with the permission of the land owner), you can collect any of the invertebrates you want, so you can feel free to collect Exogyra shells here. But the Marlbrook also contains more than just oysters, brachiopods, and snails. It has also yielded mosasaurs and even the occasional elasmosaur. There is even the possibility that a dinosaur was washed out to sea and could be found there. So if you collect in this area and find some bones, give me a call.

Many thanks to Trent Smith and the whole of Goza Middle School, not just for your hospitality, but for living the statement of Dr. Scott the Paleontologist on Dinosaur Train: “Get outside, get into nature, and make your own discoveries.”

The Very Definition of a Modern Major Researcher

Now that Labor Day has come and gone, everyone should be back to school by now. I have been absent for much of the summer and not posted nearly as much as I had hoped to. I have been working on some projects which I hoped to have up by now, but are still in process. Working two jobs right now while trying to maintain some semblence of a personal life has left me precious little energy to work on Paleoaerie. But hopefully, that should end soon and I will be back to posting on a regular basis.

In the meantime, there are some news and upcoming events I would like to share so you can put them on your calendar.

  1. I have received the audio for my talks at the Clinton Presidential Library. Unfortunately, the video was not successful. So as soon as I get the chance to sync the audio to the powerpoint, I will post it here.
  2. I have joined forces with TIES, the Teacher Institute for Evolutionary Science, sponsored by the Richard Dawkins Foundation for Reason and Science. They have a number of excellent resources on their webpage and will allow an improved opportunity to offer workshops on evolution to teachers and other interested parties. These workshops are designed by teachers for teachers and are aligned with the Next Generation Science Standards. If you are interested in a workshop, please either contact me or Bertha Vasquez, the TIES Director. You can also find them on Facebook and Twitter.TIES-banner-2
  3. I will be appearing at the Forest Heights STEM Academy in Little Rock on Friday, September 11, to discuss how the scientific method is really used by scientists.
  4. I will be appearing at the next quarterly meeting of the Arkansas STEM Coalition meeting on September 25 to talk about TIES and National Fossil Day.
  5. NFD_2015_Oval

    NFD_2015_Oval

    Speaking of National Fossil Day, make sure to put Saturday, October 17th on your calendar. The Museum of Discovery is hosting the second annual National Fossil Day event, even bigger and better than last year. Don’t miss it. National Fossil Day is a part of Earth Science Week, sponsored by the American Geosciences Institute, designed to “help the public gain a better understanding and appreciation for the Earth Sciences and to encourage stewardship of the Earth.”

Now that all the business is out of the way, I will get on with more educational material. In honor of everyone going back to school, I thought I would start a few posts about some definitions that most people generally get wrong. Today, I am going to discuss a few of the types of scientists that study past life.

imagesWhenever a scientist tells people they are an archaeologist or paleontologist, they tend to brace themselves for the almost invariable questions about the other field. In most people’s minds, all the different sciences seem to be interchangeable, with little understanding that just because someone studies the past, they don’t necessarily study everything in the past. I won’t even get into the difference between scientists who study past life and historians. I will leave that for any archaeologists who wish to tackle that issue. I get this question so often that I bought this Tshirt.

Even though we all study past life, there are important differences. Here is a Venn diagram I created that may help explain how they differ.

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As you can see, there are two main divisions in scientists who study past life: those who study humans and those who study everything else.

Anthropologists study humans, so don’t ask them about dinosaurs or mammoths or giant sharks. Don’t bring them a fossil you found. If you find a pottery shard or an arrow head, find an anthropologist. If you found a book, you might also try a historian. Ok, I said I wouldn’t get into this, but maybe just a little bit. Historians deal with written human history. So one might say that historians are a subset of anthropologists, in that they only deal with relatively recent anthropology. Many would also argue that they should not be included at all because they do not approach the endeavor with a scientific approach. While I can see the point, I can also see the point that this would also include many anthropologists, so comes across as sounding like the argument about can bloggers be considered journalists. The correct answer is that it is not as simple as that. But it’s not my field and my view of the topic is strictly as an outsider.

Paleontologists study everything that does not include humans. So please feel free to ask us about extinct organisms, as long as they don’t make pottery or arrow heads.This doesn’t mean to say that every paleontologist studies all extinct organisms. There are innumerable specialities within the field. If you ask a paleoclimatologist to identify a bone, he won’t have a clue what you are talking about. They study past climates, not bones. Just like one wouldn’t ask a podiatrist (foot doctor) to do brain surgery, don’t expect an expert in Pleistocene pollen to help you identify which type of trilobite you have, although I expect they could tell you that you do indeed have a trilobite.

But what do you do if you find a fossil of a hominid, something not quite human, but not quite an ape? That is where paleoanthropologists come in. They deal with that intersection between paleontology and anthropology, where the lines blur into shades of grey. In point of fact, all these terms are arbitrary boundaries and only serve to help us break up the studies into something manageable. Like everything else in nature, we have taken a continuous spectrum and cut it into defined sections to satisfy our need to categorize everything.

Even though there is far more life that is not human than there is that counts as human, for obvious reasons. The study of humans is more discussed than anything else. So while it is not my field, i will attempt to separate the major divisions within anthropology. Anthropologists, as mentioned study anything to do with humans. This can be broken down into two main categories. Physical anthropologists study the biology and evolution of humans. If you have human bones, they are the ones to talk to. Cultural anthropologists study human culture, their behaviors, what they make, how they interact with others. If it’s not a bone, but related to humans, ask a cultural anthropologist.

But what then are archaeologists? Do they not do the same thing as anthropologists? Yes, because they are anthropologists. They are just a subset that happens to be so well known that many people lump archaeologists and anthropologists together as if they are the same thing. But they aren’t, not quite. All archaeologists are anthropologists, but not all anthropologists are archaeologists.

Archaeologists study past human life through physical remains. Thus, they include some of both physical and cultural anthropology. They are the ones to talk to about pottery shards, arrow heads, and the like. Any physical evidence of a preexisting culture could be brought to the attention of an archaeologist. However, anthropologists cover a lot more ground, so to speak. There are cultural anthropologists that study current, existing culture. This is in fact a large field within cultural anthropology. There are even physical anthropologists that study evolutionary changes taking place within humans right now. Neither of these would count as archaeologists though.

Just as in anthropology, as I mentioned earlier, there are several different subspecialties within paleontology. Here is how the University of California Museum of Paleontology breaks it down.

Paleontology is traditionally divided into various subdisciplines:

Micropaleontology:

      Study of generally microscopic fossils, regardless of the group to which they belong.

Paleobotany: Study of fossil plants; traditionally includes the study of fossil algae and fungi in addition to land plants.

Palynology: Study of pollen and spores, both living and fossil, produced by land plants and protists.

Invertebrate Paleontology: Study of invertebrate animal fossils, such as mollusks, echinoderms, and others.

Vertebrate Paleontology: Study of vertebrate fossils, from primitive fishes to mammals.

Human Paleontology (Paleoanthropology): The study of prehistoric human and proto-human fossils.

Taphonomy: Study of the processes of decay, preservation, and the formation of fossils in general.

Ichnology: Study of fossil tracks, trails, and footprints.

Paleoecology: Study of the ecology and climate of the past, as revealed both by fossils and by other methods.

Each one of these can be broken down into even more specific specialties. Paleoecologists can specialize in biogeography, limnology, pedology, tempestology, schlerochronology,and many others. Vertebrate (and invertebrate) paleontologists can specialize in taxonomy, systematics, functional morphology, etc., but I think you get the point. There is far more that can be studied by any individual. paleontology, like any other science, is a team sport.

There are no hard and fast boundaries between these of course. Vertebrate and invertebrate paleontologists can and do study taxonomy, biogeochemistry, paleoecology, and taphonomy, and others all at the same time. Paleontology is highly interdiscplinary and requires knowledge in a lot of different fields. But many scientists tend to spend most of their time in a specific area.

So if you have a question, you will get the most detailed answers from someone in the right specialty. Choose wisely and you will get your questions answered. If you don’t, go to grad school, discover them for yourself and let everyone else know about it.

Dinosaurs by Aliki

Aliki Brandenberg, known mostly simply as Aliki, has written several popular books for children in the Let’s-Read-And-Find-Out Science series published by Harper Collins. Among these books are ones about fossils and dinosaurs written for 5 to 9-year -olds (I think 4-8 would be a better range, as many 4-year-olds will like the books and most nine-year-olds will have moved on to books with more information). When they came out in the 1980s, they were widely regarded as excellent books for children. The books were voluminously illustrated with colored pencil drawings of fossils and people studying them. The main text was supplemented with word balloons for the human characters, supplying interesting tidbits and additional information, so should not be ignored. Unlike many books of the time, these were about as accurate as one could expect to get without going into so much detail that a person of that reading level would feel overwhelmed.But it has been 25 years or more since then. We’ve learned a lot since then. How have they held up? Surprisingly well, for the most part, better than the majority of books published at the same time. I will review four of them here, two in this post and two in a following post. Some people might find the reviews a bit lengthy, so here they are in a nutshell: still good reads for kids, even better with a few additional comments to update them and correct a few misconceptions that kids might get from the simplicity needed to pare down complicated subjects into something that would fit the space constraints and interest levels.

Fossils Tell of Long Ago

alikifossilsbookby Aliki Brandenberg

Publication Date: 1972, revised 1990.

Harper Collins Publishers. ISBN: 978-0-06-4455093-5

AR Book Level: 3.6

Fossils Tell of Long Ago endeavors to explain what fossils are, how they form, and what they can tell us. In a quick 32 pages, Aliki provides a wealth of information well written for the intended reading level of early elementary kids.

Fossils starts off describing what fossils are and how they are formed. The description of the fossilization process is simplistic and doesn’t get into the microbes precipitating minerals around the bones during decomposition, but that was not known when the book was written and the description in the book is sufficiently accurate for the level of reader at which the book is aimed. I do like the use of the famous Xiphactinus fossil as the lead example as it is a fascinating fossil in its own right and thus a good fossil with which to hook readers. Aliki’s description of coal as a fossil is great. She does a good job of introducing different types of fossils, even including different pieces of information that may be gleaned from fossil footprints.alikifossilsbook2

Aliki then goes on to talk about mammoths in ice, amber, and how fossils can tell us about the environments when the rocks were deposited, introducing many more types of fossils along the way. She ends the section by reinforcing the utility of fossils to tell us about past environments and organisms that no longer exist, even putting in a plug for museums.

The book ends with showing how to make your own fossil track and thoughts about how people in the future may interpret it. Best of all, she ends on a positive, encouraging note that anyone can find fossils, even the kid reading the book, and discover something no one else in the world knows. And that is a powerful motivator.

All in all, the Fossils book stands up very well and can still be recommended as a great book for kids.

Dinosaur Bones

alikidinosaurbonesby Aliki Brandenberg

Publication Date: 1988 (Amazon lists the publication date as 1990, which differs from what is printed in the book).

Harper Collins Publishers, ISBN: 978-0-06-445077-5.

AR Book level: 3.7

“Dinosaur Bones” tells about the early history of the study of dinosaurs and briefly discusses dinosaurs and the world of the Mesozoic. This book does not hold up quite as well as the “Fossils” book and shows its age by being out-of-date in some places, but is still reasonably accurate a good read for young kids. It provides an interesting glimpse at the beginnings of the modern studies of dinosaurs (dinosaur bones have been found for millenia, but modern scientific study is much more recent) and a very brief introduction to dinosaurs and their world.

This book, like almost every other book, has a European bias. On the very first page, it says the Dr. Robert Plot was the first person to describe a dinosaur bone in 1676. He had no idea what it was and he described it as possibly a giant human thigh bone or some other such animal. He was hardly the first to find dinosaur fossils and try to describe them though. Native Americans, ancient Greeks, and many others found them far earlier. They just did not recognize them as dinosaurs. Fossil Legends of the First Americans and The First Fossil Hunters:Paleontology in Greek and Roman Times, both by Adrienne Mayor, are filled with accounts of early fossil hunters.

alikidinobones2The book begins by describing how she was introduced to dinosaurs and her curiosity about how scientists know what we do about past life, which she begins to answer by talking about people finding fossils. The book provides an excellent short history of the early scientific study of dinosaurs by Europeans, hitting all the famous highlights. The best part of this section is her emphasis on early ideas changing with new fossils and new data. She presents dinosaur paleontology as a dynamic process, with ideas being revisited and revised in the face of new evidence, which is a great thing to put into a book for kids.

The book then delves into the world of the dinosaurs, showing that the world was much different than it is today. I like that this was included and I realize there were space limitations, but I have a small problem with this section. The Mesozoic Era, what is commonly known as the time of the dinosaurs, lasted for over 200 million years. That is a huge time. In general, the description of the continents being joined together into one land mass was accurate for a good bit of that time, but it broke up during the Mesozoic,which had important effects on the evolution of the dinosaurs. The temperatures were also only warm everywhere, as stated in the book, if one considered temperatures warmer than current “warm.” Neither the Arctic nor Antarctic were covered in glaciers, but it was still cold enough to snow and reach frigid temperatures at night in the poles. Basically, it is not possible to compress the diversity of climate and landforms of 200 million years across the entire world into two pages and six sentences. But given that constraint, she did the best that could be done. At the very least, she presented the concept of great changes in the globe over great expanses of time, which is a substantial achievement for a book aimed at elementary kids.

Too complicated for a book meant for young kids, but  shows why not indicating there are other ways to tell time is misleading. Talkorigins.org.

Too complicated for a book meant for young kids, but shows why not indicating there are other ways to tell time is misleading. Talkorigins.org.

Following this section are two pages describing how fossils are formed and geologic time. She mentions the important concept of dinosaurs evolving. For the space available and the intended audience, the book does remarkably well. For the purpose of just introducing the concepts to kids, they are handled succinctly and clearly. The biggest place where it falls down is saying that scientists tell time by looking at the order of the fossils. This is indeed one way, but if that were the ONLY way, it would be a circular argument. You can’t use the fossils to date the rocks and the rocks to date the fossils at the same time without additional evidence. This method also only provides relative dating, there is no way to really tell how old the rocks and fossils are this way, only the order they were laid down. There are some rocks though, such as ancient lava flows or ash beds, for which we can get absolute dates using radiometric techniques. Between the two dating methods and comparing rock units from different areas to each other, we can get reliable dates for all the rock layers. Having said that, the major geologic time units were devised by looking at the order of fossils. It was only later that we learned how to provide the absolute dates, which told us how old the rocks really were. I would have preferred a simple change of wording to say that finding fossils is ONE of the methods scientists use to tell time and not make it look like it is the only way. The change may not look like much, but it really does make a big difference and many kids will pick up on the distinction so long as adults don’t give them misinformation.

The final few pages describe the history of the dinosaurs in a few sentences. The Triassic Period is done well for the allotted three sentences and the illustrations provide examples of some of the dinosaurs. The only problem here is the description of Heterodontosaurus, which is out of date (for cool information on this unusual animal, go here and here… no, really, check it out).

The Jurassic Period is a bit problematic in that it has the giant, long-necked sauropods tromping around what look to be swamps and dragging their tails, which is no longer considered accurate. Interstingly, all the carnivores are shown in dynamic, tails-up poses. The Cretaceous Period starts with saying “dinosaurs had taken over.” Dinosaurs were dominant throughout the Jurassic Period, long before the Cretaceous. The dinosaurs are also drawn too much in the old, upright positions. More than any other page, this one looks like a throwback to an earlier artistic era. In the entire section, the dinosaurs are drawn very simply and generically, despite the fact that they are named with specific names.

The final page starts with “Then suddenly, they all died out. No one knows why.” This is followed by several things scientists don’t know about dinosaurs. By and large, it is true, but we have made great progress and can now provide at least partial answers to all of them now. We now have some very good ideas about why they died out. There is also considerable debate about how “suddenly” it was. Most notably, dinosaurs didn’t all die out, just most of them. Birds are directly descended from the Mesozoic dinosaurs and are the most diverse group of vertebrates that live on land. Scientists are also making strides to answer the final questions the book states about their colors, what sounds they made, and their metabolism.  While there are still many gaps, we have made much progress on those questions. As a result, I would recommend that anyone reading this book to kids mention how old the book is and that a lot of work has been done since then to find answers to those questions, but there is still much more to do.

Not ALL dinosaurs died out.

Not ALL dinosaurs died out.

 

Next time, I will review Digging Up Dinosaurs and Dinosaurs are Different. When my kids were in preschool, I read them Digging Up Dinosaurs several times. Stay tuned.

 

Mystery Monday

Time for another Mystery Monday fossil. Spend a little time to digest the image, then tell us what you think it is.

mysteryfossil9222014

3D: It’s Not Just for Movie Theaters

Jim Lane is talking about something that has been on the mind of a lot of education researchers lately. If you read much in the way of education literature at all, I am sure you will have run across many a discussion of how to improve learning by engaging the students with materials they find interesting and challenging them to solve relevant problems in a creative manner. Doing that means moving beyond the simple worksheets and memorization. It means using the newly available tools to bring the material to life and having the students work on, as one of Mr. Lane’s students called it, the edge of science.

Some of those new tools are in the realm of 3D scanning and modelling. This has allowed many museums and researchers to put some of their work online in a way that allows much more interaction than simple photos. You can, for instance, examine the head of a 2,200-year-old Chinese terracotta warrior housed at the Emperor Qin Shi Huang’s Mausoleum Site Museum or skeletons in an underwater cave from the comfort of your own home. This has great benefits for conservation and research, allowing digital preservation of fragile artifacts and researchers from all over the world to view the objects without having to spend the money to physically examine them. Much of the time, researchers will still want to see the real thing, but there are numerous studies that can be done with only the scanned images. There is even some research that can only be done on the scanned items, making the scans in a way, more important than the item itself. More to the point here, 3D scanning also opens up the object to viewing by people the world over, the vast majority of whom will never have the chance to visit the museum and see the real item.

So where can you see some of these items? There are several places on the net you can go. Here we will focus on those useful for evolutionary topics, such as fossils and anatomy (comparative anatomy with modern organisms is the heart of paleontological research). Many of the sites allow you to download the scans and print them out if you have access to a 3D printer, which are becoming increasingly common as the prices drop down to the point many individuals can buy their own and schools are starting to make them available to their students. Be warned, interactive 3D elements generally take a lot of graphics computation, so try to limit any other graphics you have up, i.e. close other browser windows, don’t try running a game in the background, the general rules of using a program with a lot of graphics. But as long as you have an up-to-date browser with Quicktime and Java, most computers these days should be able to handle it just fine (although a warning about Java, the security updates in the past year or so have made the more recent versions of java incompatible with earlier versions, so unless the developer for the site has updated their program, it may not work).

The following sites are in no particular order, so with that in mind, the first place on this list you might want to visit is Smithsonian X 3D, a website the Smithsonian recently put up showcasing objects from their collection they have scanned. At the moment, there is not a lot, but the site is new and they will be adding much more as they go along, so be sure to check back regularly. Right now, you can see 3D images of whale fossils, a mammoth, a blue crab, an orchid, a bee, and several other historical objects. Included in the collection is a scan of President Obama, the first ever 3D Presidential portrait. The basic 3D viewer is easy to use, although a few of the more advanced controls are not altogether intuitive. The website provides a brief description of each item, along with articles and videos on some of the items and the process of scanning them, including a page for educators on the use of the objects in the classroom. The Smithsonian also has more 3D collections on their human origins site. You might think that they would only have human fossils, but they have much more. You can certainly find hominid fossils, but along with them are numerous primates from Aye-Ayes to gorillas, and a large variety of other animals, from bears and cheetahs to komodo dragons and vultures. While you are there, you can a diverse array of information on human evolution, including teacher guides, lesson plans, multimedia, current research, everything you need to teach a human origins unit.

Another place you will want to check out is the Visual Interactive Anatomy pages by Dr. Lawrence Witmer at Ohio University. He and his students spend a lot of time scanning fossils and modern animals using a medical CT scanner at nearby O’Bleness Hospital or a micro-CT scanner on campus. They have put together several pages that illustrate the anatomy of several modern animals, including an opossum and the heads of a human, rhino, iguana, alligator hatchling, and ostrich. They have also collaborated with Dr. Casey Holliday on an adult alligator. The adult alligator page even has individual pages for every bone in the skull. On these pages, you will find interactive 3D pdfs and videos of the scans and reconstructions, which have a variety of structures labeled, identifying the bones, brain cavity, nasal passages, etc. In addition, you will find news and behind the scenes excerpts, and links to the published research on the specimens. On the 3D Visualizations page, you will find similar movies and 3D pdfs for a variety of dinosaurs (including Tyrannosaurus rex, Majungasaurus, and Euoplocephalus, along with several birds) and mammals from the platypus to deer to Archaeotherium, one of the group of animals often called “terror pigs”.

A website that is sure to grow is the NIH 3D Print Exchange. This site allows people to share their own 3D files for other people to download and use. The website focuses on biomedical applications, but currently you can find a variety of brains, bones, molecules, DIY lab equipment, and more. The more part I am sure will grow as people explore the site and add their own models. You can also find tutorials for making your own 3D models using 3D visualization software, and links to open source software such as Blender, FreeCAD, and Google Sketchup, as well as 3D printing services such as i.materialize and Makexyz and others.

Digimorph, or more properly Digital Morphology, a National Science Foundation Digital Library, is a site run by the CT facility at the University of Texas at Austin, one of the premier CT facilities in the country and the primary place American paleontologists go to get their fossils scanned. Digimorph provides access to these scans for the public and researchers the world over. On this site, you can find videos of scans and 3D reconstructions, some of which can be downloaded for 3D printing, for hundreds of animals, including a variety of avian and non-avian dinosaurs, along with extinct and modern species of mammals, reptiles, amphibians, fish, and even plants, coral,  crustaceans and other invertebrates. Along with the scans and 3D reconstructions, you can find descriptions of each specimen, a bibliography of research published on them, and links to useful sites for software, information on CT scanning, and other related sites. The downside to the site is they provide nothing specific for educators and the specimens that have downloadable 3D renderings are a small fraction of the total specimens available in video form, and none of them of the dinosaurs, which are only available as video animations. Nevertheless, for sheer quantity of 3D images for a diversity of animals, there is no place better.

The final site on the list is swiftly becoming the place to go for virtual fossils.GB3D Type Fossils Online project, or simply GB3D, is a website run by the British Geological Survey, Amgueddfa Cymru (National Museum of Wales), Oxford University Museum of Natural History, and the Sedgwick Museum of Earth Sciences. As the name suggests, the site is a repository for information of “type” fossils. If you don’t know what a “type” is, they have a handy guide explaining the different types. In this case, they aren’t talking about what kind of fossil it is, but things like holotypes, fossils designated in the original description of the fossil, which all others are compared to, which make them very important to scientists studying those kinds of fossils. If you want to see United Kingdom fossils, this is the place to go. They have hundreds of fossils in 3D and hundreds more in 2D. On this site, you will find a great diversity of plants and animals with high quality photographs, many of them also have stereophotos (get your 3D glasses with those red and blue lenses) and 3D models. In addition, you will find information about the fossil, such as what it is, when and where it was collected, how old it is, and contact information for the institution that holds the fossil itself. They also have a page describing the more commonly found fossils, all of which happen to be various invertebrates or fish. You will also find free programs used to view and work with 3D images you can download. They have available MeshLab, SPIERSview, and Adobe 3D Pdf Reader. Finally, you will also find links to a variety of educational resources for primary and secondary schools, universities, and the public.

Hang gliding in the Oauchita Mtns. Photo by www.mena-ark.com

Hang gliding in the Oauchita Mtns. Photo by http://www.mena-ark.com

If you want to inspire people to learn, you have to bring them right up to the edge of that knowledge cliff so they can peer over it at the wondrous space beyond, exposing them to the unknown in all its glorious mystery. Help them understand the foundations of the cliff, teach them how to build their own wings, and then push them off that cliff so they can soar into uncharted regions. When they return, they will have a better grasp of how the cliff is formed and what its boundaries are. They just might also find that cliff sticking out a little farther than when they flew off it. And when they do, you won’t have to push them, they will leap on their own. Of course, you will then have another problem: keeping up with your students. So keep your own wings in good repair. I do hope I have helped you build your wings a little stronger. If you know of any other sites that may be of use, please let us know in the comments section.

I will let Dr. Witmer finish this out and let him explain a bit about his projects and why approaches like this, particularly with dinosaurs, are useful educational tools.

 

The ethics of fossil collecting

Image

Today’s Google doodle celebrates the 215th birthday of Mary Anning. She was one of the first people to help usher in the modern age of paleontology as a science and was the prime worker on the Jurassic Coast near Dorset, England, probably the most important fossil site for marine reptiles in the world. The Natural History Museum of London calls her “the greatest fossil hunter ever known..” Among other finds, she is credited for finding the first correctly identified skeleton of an ichthyosaur, the first complete specimens of a plesiosaur, the first pterosaur outside Germany, and identifying coprolites as fossil feces. Until that time, they were called bezoar stones, indigestible masses found within the digestive system. They were rumored to be an almost universal antidote for poisons and were used as such in J.K. Rowling’s Harry Potter series. The first woman to receive a eulogy at the London Geological Society, an honor given only to distinguished member scientists (she wasn’t even a member because the society did not accept women at the time, they just took her work and published it under their names), Mary Anning was widely sought after by researchers in her time for her expertise.

This brings up an interesting debate. It is hotly debated what role commercial fossil dealers have in paleontology. The current majority consensus as presented by the Society for Vertebrate Paleontology is that they should be stopped because all the fossils they collect are sold, almost always, to private collectors, thereby removing them from scientific study. Fossils that are not in the public trust (like a museum) are not accessible to other scientists to study, so all the knowledge that may be gleamed from their study is lost to the public. They explicitly state this in their bylaws. Section 6, Article 12 states: “The barter, sale or purchase of scientifically significant vertebrate fossils is not condoned, unless it brings them into, or keeps them within, a public trust. Any other trade or commerce in scientifically significant vertebrate fossils is inconsistent with the foregoing, in that it deprives both the public and professionals of important specimens, which are part of our natural heritage.”

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The tyrannosaur named Sue. Wikipedia.

They have a point. Few fossils collected by commercial fossil dealers ever get scientifically studied. Who knows how many priceless and important fossils are locked away in someone’s private collection. Museums do not have the resources to compete with private competitors to buy fossils except in the rarest of occasions and even then, it depends on the finances and good will of private individuals willing to donate to the museum for that purpose. The tyrannosaur named Sue sold at auction for $7.6 million to the Field Museum in Chicago, who needed the help of the California State University system, Walt Disney Parks and Resorts, and McDonald’s, along with numerous individual donors to raise the money. Researchers collecting fossils must always be on their guard to protect their dig sites due to the common occurrence of thieves stealing fossils from their dig sites to sell them. Many paleontologists have stories of finding a skeleton at the end of the season and having no time to collect it, only to come back the next season to find someone has collected the sellable parts and not uncommonly have smashed the rest. Even if the fossils find their way to a public institution where they can be studied, most commercial fossil collectors do not take sufficient notes about location and all the details at the site to make the find reliable enough to study well. It is often said that a fossil without provenance data has little more worth than having no fossil at all and for good reason. If you don’t know where a fossil came from, there is little you can say about it and it is impossible to place it in context with other fossils.

On the other hand, commercial fossil collectors say that without them, most of the fossils they collect would have eroded away and been gone completely with no record of them ever having existed at all. There simply aren’t enough paleontologists and money in academia to collect all the fossils they do and they are right. The tyrannosaur Sue is a great example of a dinosaur fossil that may not ever have been found if it were not for commercial fossil dealers. What makes this point important for this essay is that Mary Anning was a commercial fossil dealer. She funded her research and supported herself by selling fossils. Without the income she received from fossil sales, she would never have been able to make the discoveries she did.

Possibly the only known photograph of Mary Anning and she is not even credited in the photo, which is called The Geologists. 1843, Devon. Salt print by William Henry Fox Talbot. Photograph: The National Media Museum, Bradford

Possibly the only known photograph of Mary Anning and she is not even credited in the photo, which is called The Geologists. 1843, Devon. Salt print by William Henry Fox Talbot. Photograph: The National Media Museum, Bradford

So who is right? Maybe they both are. It is undeniable that unscrupulous poachers and fossil dealers steal and destroy priceless fossils which never enter the public and academic consciousness, but it is also undeniable that commercial fossil dealers have contributed greatly to our knowledge of paleontology. The AAPS, Association of Applied Paleontological Sciences, an organization representing commercial fossil dealers, advocates for responsible collecting, having a professional academic work with commercial fossil dealers so any finds can be studied. Their position would indeed help bridge the gap between the academic and the commercial dealer. However, this requires the benevolence of the collectors and many, possibly most, are uninterested in letting academics study their fossils. While the fossils may be able to be studied during the time they are found and prepared (removing the encasing rock and putting the pieces together), most of the study comes after this point. A fossil in private hands can easily become lost and access is at the mercy of the owner. A museum, on the other hand, is required to maintain records of the fossils and provide access to anyone who wants to study them.

paleo_images0.Par.11277.Image.150.355.1So what is to be done? Currently, it is illegal to collect vertebrate fossils on Federal land. The reasoning is that Federal land is owned by everyone. As such, anything on Federal land must be protected for all citizens, making collections for private sale not in the interests of the country as they take fossils out of the public trust and therefore inaccessible to the public. States have their own rules, some make it illegal, others have no specific laws concerning fossil collections. On private land, there are no restrictions. Any fossils found on private property are the property of the land owner and they can do whatever they want.

What is the correct answer? That depends on your point of view. Certainly the collective point of view has changed through time. What do you think?

Mystery Monday

Mystery Monday

Time for another Mystery Monday fossil! See if you can figure out this wrinkly rock.

Mystery Monday

Mystery Monday

I hope you had a blast over Spring Break. Here is a fossil you might find in Northwest Arkansas. See if you can figure out what it is.

Fossil Friday, Revenge of the Serpent

Mystery Monday this week fell on St. Patrick’s Day, so to celebrate, the following image was posted for the mystery fossil of the week.

pterosphenusSt. Patrick was well known for driving all the snakes from Ireland, at least so the myth goes. In reality, there never were any snakes in Ireland for St. Patrick to drive out in the first place. But unlike Ireland, Arkansas has always had snakes. Right now, we have a diverse population of snakes, including boasting more different types of venomous snakes than most other states, being one of only ten states that have all four types of venomous snakes in the country (there are roughly twenty separate species, but they all fall into four main groups). Here you may find the copperhead, coral snake , cottonmouth (aka water moccasin), and the rattlesnake (including the Timber, Western Diamondback, and pygmy rattlers). At least we can take comfort that we are just outside the ranges of the Massasauga and Eastern Diamondback rattlesnakes and we don’t have the diversity of rattlers seen in places like Arizona and Texas (which may win the prize for most venomous snakes in the country if both species number and diversity are taken into account).

Venomous snakes of Arkansas. Baptisthealblog.com

Venomous snakes of Arkansas. Baptisthealblog.com

AR 40 Mya, by Dr. Ron Blakely

AR 40 Mya, by Dr. Ron Blakely

In the past though, we also had other snakes, including Pterosphenus schucherti, also known as the Choctaw Giant Aquatic Snake, a giant sea snake that lived here in the late Eocene roughly 35 million years ago. The Eocene was a much warmer time. In fact, this period falls at the end of what is called the Palaeocene-Eocene Thermal Maximum. There were no polar ice caps during this time, with at least double the amount of carbon dioxide and triple the amount of methane than what we see now. Because of this, Louisiana was pretty much under water and Arkansas had wonderful ocean front property, along with a lot of swamps and marshes. It is likely the cooling during this period into the Oligocene Period, that caused the extinction event that wiped out these snakes, along with several terrestrial mammals, including a variety of Perissodactyl horse ancestors, artiodactyls (cloven hoffed mammals), rodents, and primates.

pterosphenusmodel

Pterosphenus model at the Florida Museum of Natural History. It is too wide, though, as noted by the staff of the VMNH paleontology lab, who took this picture.

This was the perfect environment for a number of different snakes, although we don’t have fossil evidence of many. One that we do have is of Pterosphenus. This snake had tall, narrow vertebrae, indicating adaptation to an aquatic lifestyle. In fact, it probably was not able to support itself on land very well due to its thin body.

Little file snake, Acrochordus granulatus. www.markshea.info

Little file snake, Acrochordus granulatus. http://www.markshea.info

Sea snakes today rate as some of the most highly venomous snakes in the world. However, there are nonvenomous ones as well, such as the marine file snake, Acrochordus granulatus, which live in coastal regions between Asia and Australia. Those of today are relatively small snakes, ranging from half a meter to just over 2 meters (2 feet to 7 feet or so). Pterosphenus, on the other hand, reached lengths of 2.3 m to 5.1 m, or possibly larger.

Unfortunately, we don’t know a whole lot about these snakes, other than they were clearly aquatic. The bones that have been found with them, such as whale bones, have indicated marine waters. Fossils of these snakes have been found in eastern Arkansas, in Saint Francis County in the Eocene deposits around Crow Creek called the Jackson Group.