Sunday, July 27, 2014

Changyuraptor: Prehistoric Animal of the Week

Earlier this month, a newly discovered genus of dinosaur was discovered with long, beautifully preserved feathers.  Check out Changyuraptor yangiChangyuraptor was a meat-eating dinosaur, related to Velociraptor and Deinonychus, that lived during the Early Cretaceous period, 125 million years ago, in what is now China.  It measured about four feet long from snout to tail, roughly the same size as a large hawk. (Remember, about half of that length is tail.)  The genus, Changyuraptor, translates to "long feathered hunter" because some of the tail feathers from this animal were a foot in length, longest discovered of any non-avian dinosaur.

A gliding Changyuraptor drops in on a sleeping Microraptor.  Reconstruction by Christopher DiPiazza.
 
Changyuraptor is fascinating not only because it was found with feathers intact, but because of the fact that it also had long primary feathers on its legs!  In a sense this dinosaur had "four wings" and may have used them all to help it glide or parachute down from trees.  Changyuraptor wasn't the first dinosaur to be discovered with hind wings, however.  The first was the closely related, and much smaller, Microraptor.  The lesser related, and older, Anchiornis also had long feathers on its legs and feet.

Fossil of Changyuraptor yangi.  Check out those feathers! 

Despite its appearance, Changyuraptor probably couldn't fly.  It's arms and torso just don't appear to be designed for it.  It can, however, help scientists figure out the origins of flight in modern birds.  It is possible that dinosaurs like Changyuraptor may represent an evolutionary offshoot in the family tree near the dinosaurs that would eventually give rise to the flying birds we see around us today.  Maybe four wings was overkill?

Am I the only one who realized that comedian, Demetri Martin actually thought up of four-winged dinosaurs completely independently of their actual scientific discoveries?  In one of his famous stand up routines he invents an animal called a "double hawk" that had four wings coincidentally in a very similar (if not sort of crudely drawn) arrangement as that of dinosaurs like Changyuraptor!

Illustration of the double hawk by Demetri Martin.  Possible example of convergent evolution?

That's all for this week!  As always feel free to comment below or on our facebook page!

References

Gang Han, Luis M. Chiappe, Shu-An Ji, Michael Habib, Alan H. Turner, Anusuya Chinsamy, Xueling Liu & Lizhuo Han (15 July 2014). "A new raptorial dinosaur with exceptionally long feathering provides insights into dromaeosaurid flight performance". Nature Communications. 5, Article number: 4382. doi:10.1038/ncomms5382.

Sunday, July 20, 2014

Saltasaurus: Prehistoric Animal of the Week

Enter Saltasaurus loricatusSaltasaurus was a sauropod dinosaur that lived in what is now Argentina, during the late Cretaceous period, between 70 and 66 million years ago.  It was small for a sauropod, measuring about forty feet from snout to tail.  Its genus name translates to "Salta lizard/reptile" in reference to Salta, a city near where it was discovered. 

Saltasaurus loricatus reconstruction by Christopher DiPiazza.

Saltasaurus is a pretty well studied sauropod.  There are many bones of it on the fossil record, but its real claim to fame was its skin.  Paleontologists found out, thanks to some beautifully preserved fossil remains, that Saltasaurus would have actually had small nodules of bone embedded in its skin.  We see these same sort of structures, called osteoderms, in modern crocodilians and other kinds of dinosaurs, most notably the ankylosauroids.  Never before had sauropods ever been known to have had armor!  It was always assumed that sauropods could get by with just their size, and perhaps tails as weapons.  It is is theorized that Saltasaurus had this dermal bone armor to help protect itself from predators since it indeed wasn't as large as some of its relatives.

Saltosaurus osteoderm fossil.

Saltasaurus belonged to a group of sauropods called the titanosaurs.  Since the discovery of Saltasaurus, other titanosaurs are commonly reconstructed with osteoderms too.  Like all sauropods, Saltasaurus would have stripped leaves off of branches with its teeth, which were only in the front of its mouth.  Titanosaur teeth were long and rod-shaped.  It also had a rather wide, barrel-shaped body, which probably was used for breaking down and fermenting all that tough plant material it was eating all the time.  Since its teeth weren't designed for chewing, Saltasaurus would have swallowed all its food whole and allowed its huge stomach chamber to do all the digesting for it, which would have required a lot of space and energy.  Just think of modern cattle and how big their stomachs are. (four chambers!)  There is a solid chance that sauropods like Saltasaurus also would have been very gassy animals because of this.  (teehee farts!)

Saltasaurus eggs have also been discovered.  They were almost perfectly round and only measured about five inches long in diameter.  Even more interesting, many clutches of these eggs have been discovered all nearby each other and even on top of each other year after year.  This suggests that like many modern reptiles, like certain turtles and birds, mother titanosaurs like Saltasaurus would have laid eggs at the same time in the same place each season.

Saltosaurus egg on display at the Museum of Ancient life in Utah, USA.

Saltasaurus, as well as titanosaurs as a whole, are important to paleontology because they proved that sauropod dinosaurs persisted successfully up until the very end of the Mesozoic era, 65 million years ago.  Prior to their discovery, it was believed that most sauropods died out at the end of the Jurassic period and were replaced by other plant eaters like the hadrosaurs and ceratopsians.  We now know that this is only true for the northern hemisphere.  In what is now South America, Africa, and Australia, sauropods were still the reigning plant eaters of their time!

That is all for this week!  As always please comment below or on our facebook page.  Have a request?  Let me know!

References


Coria, R.A. and Chiappe, L.M. 2007.Embryonic Skin From Late Cretaceous Sauropods (Dinosauria) of Auca Mahuevo, Patgonia, Argentina. Journal of Paleontology v81(6):1528-1532 doi:10.1666/05-150.1


Idols and Idolatry

Who is your idol?

I found myself asking this question to myself in the wake of the public scrutiny of the behavior of theoretical physicist Richard Feynman (I recommend reading Janet Stemwedel's in-depth examination of the situation). In short, he made important contributions to his field and is considered a brilliant scientist, but his actions towards the women he associated with professionally were extremely disrespectful, and arguably harmful to the goal of inclusion and fair treatment of women in science. Many in the field look to Feynman as a role-model or idol, and have responded harshly to the critiques.

The World English Dictionary defines idol as
"1. a material object, esp a carved image, that is worshipped as a god,
2. Christianity, Judaism any being (other than the one God) to which divine honor is paid,
3. a person who is revered, admired, or highly loved."

Dictionary.com has a different version of definition 3 for idol: "any person or thing regarded with blind admiration, adoration, or devotion. Madame Curie had been her childhood idol."

Both versions of the definition for idol carry with them an unrealistic burden to apply to any one person, and that burden comes with a heavy responsibility. Theoretical physics is not the only academic field in which idols exist. Every field has people who are treated as idols. There are idols in paleontology.

I had a couple of idols growing up, and I was fortunate in that I admired scientists who are also good people before knowing anything about their non-research conduct: they are ethical, fair-minded, and generous people. My early admiration of these scientists stood the test of time and my maturity. I still admire them, even though I have grown enough to realize that, although they are great scientists and great people, they will never be above scrutiny or critique. No one is.

Idols and role-models can be a potentially positive influence for young people looking to enter the sciences. They can inspire the younger generation to study. If their role-models write or appear for the public, they introduce young people to science concepts they might not otherwise encounter until their post-secondary education. Role-models inspire students to explore, to challenge old ways of thinking, and make the sciences so engaging that the students can see themselves participating.

There is a fine, fuzzy line between a role-model and hero worship, between a mentor and an idol. Idolatry can lead to mimicry, and while mimicry is supposedly a type of compliment, there are many examples in nature of toxic organisms being mimicked. It may be a heavy-handed analogy, but in the case of students, they may not immediately realize that the person they model themselves after is displaying behaviors that do more to erode the cooperative and inclusive goals of the scientific community than to uphold them.

I have come to find the idea of promoting someone to idol status disturbing. While we can cite examples of scientists who repeatedly demonstrate positive academic and community ethics, we should not promote the idea that any one should strive to "be like" another researcher. When a person is idolized, it is too easy to dismiss their less than noble actions for fear of tarnishing the shiny image, and those who critique the idol are portrayed as destructive. I have heard many say (and have stated this myself in my naive days) that it doesn't matter who the scientist is as a person as long as their academic work is sound, and that all that matters in the end is the product. I may have believed this once upon a time, but now I firmly believe this statement is a pile of steaming horse-apples.

Stemwedel hits the rock squarely with the Estwing:

'Do we have a scientist who is regularly cruel to his graduate student trainees, or who spreads malicious rumors about his scientific colleagues? That kind of behavior has the potential to damage the networks of trust and cooperation upon which the scientific knowledge-building endeavor depends, which means it probably can’t be dismissed as a mere “foible.”'


I realize that a scientist can be what I would colloquially describe as a jerk, a sleaze, or as dancing down the slippery slope of ethically dubious behavior and have also produced notable work. For example, I can't refuse to cite someone's paper just because I think how they treat their graduate students is despicable. However, their scientific contributions do not excuse or lessen the negative impact of their behavior on their community. They have set the stage for the conduct of future students on a shaky foundation. This should not be ignored.

How a scientist behaves towards their colleagues and subordinates professionally and personally is as important to the science community as their body of work, if for no other reason than they are maintaining the trail that the next academic generation will follow. All of the good within the community that currently exists is because of the attitudes fostered by our predecessors that we, knowingly or unknowingly, have internalized and are projecting as normal. The same applies to the negative actions that happen within our community. Whether we like it or not, whether we want the responsibility or not, our actions in and out of the field/lab are demonstrating what is normal for our field. We are demonstrating what we accept as acceptable behavior. It becomes our responsibility as soon as we start interacting with students.

It is also our duty to publicly criticizing behavior that we would not want to see demonstrated in our future students, regardless of the work conducted by the person/people. We have the responsibility to denounce the behaviors that sow mistrust, uncertainty, and even fear in the scientific community, and work harder to prevent them. If we do not want to see our future students 1) treat their peers or subordinates without personal respect, 2) treat underrepresented groups as inferior, 3) sabotage, undermine, or otherwise inhibit the work of their peers or subordinates, we have to model the type of behaviors that we want to see passed on to the next generation of students. We cannot excuse bad behavior as "part of the package" of doing research just because "it's always been done this way." If we receive criticism for our behavior, we have the responsibility to listen, examine, and change to foster a positive community.

In the end, the only people who are responsible for the climate we foster in our scientific community are ourselves. Sooner or later, someone is going to look up to you: who do you want them to see? More specifically, if you were on the receiving end of your actions towards your peers and subordinates, would you feel welcome in your scientific community?

Thursday, July 17, 2014

Field Work in New Mexico 2014

Greetings everyone!  It is time again to recap how Gary and I's time went last week doing field work in the badlands of New Mexico.  If you have not already, be sure to review my post about it from last year and also take time to read Gary's post from last week about his experiences excavating and prepping a specific fossil.

Sadly I can't give you detailed descriptions on everything we were able to dig up, nor can I post photos of prepped fossils that have not been published.  (I wish I could there are so many exciting new things over at the Mesalands Dinosaur Museum!) I can, however show you bits and pieces of our experiences over there that might give you a feel of what it was like. 

First things first lets look at the nature of the place.  As you know my background is heavily engrossed in biology, specifically the animal sciences, so whenever I visit a new ecosystem I am extra attentive to the creatures I can find around me.  Last year I saw two kinds of lizards.  This year I found another kind that I instantly recognized, a beautiful Collard Lizard!

Collard Lizard, Crotaphytus collaris, I managed to photograph in the field.

Collard Lizards get their name because of the black coloration that forms a ring around their necks.  Despite the fact that I didn't see any last year, they were the most common lizard I saw this year.  At the dig site I could Identify at least two individuals (a male and a female) who would appear nearby at least once per day.  The site must have become their territory sometime within the last year. 


I also managed to see a few Whiptail Lizards.  These guys have beautiful spotted patterns on their skin, and possess an extremely long tail.  (Which is how they got their name.)

One of the several Whitpails we also saw out there.  This one was eating a caterpillar.

On one of the last days there I found a solifugae!  (Not a dead one like last year) The little arachnid was running across the motel carpet!  Despite the alien (even creepy) appearance of this animal, I made sure to gently let her go on her way outside.  Arachnids are not generally harmful to humans and play an important role in hunting other small invertebrates. (cockroaches and mosquitos for instance) 

Solifugae I found in our motel room.  They can grow a LOT bigger than this.

 Speaking of cool invertebrates eating other invertebrates, we saw many beautiful dragonflies while in the field.  They would cruise around over the site in large groups, no doubt hunting the mosquitos and gnats that were pestering us.  Thanks, guys! 

This striking orange individual favored our truck's antenna as a perch.

 Once we actually started digging it wasn't long before fossils started turning up.  I was privileged enough to get the opportunity to help excavate a juvenile Typothorax armor plate.  We have found many plates from these amazing reptiles before, some over a foot wide!  This one, however was the same shape as one of the larger ones (so we know its not just from another part of the body on an adult) just tiny.  Video!


Gary made a pretty rare find while he was removing rocks from the site, a freshwater clam!  Remember, this site used to be the bottom of a lake 200 million years ago.  We find plenty of Redondasaurus, Typothorax, Shuvosauroids, and Coelophysis, LOTS of fish, but not too often do we actually find mollusks.  We almost mistook the clam as just another rock at first!  Video!


Overall it was a pretty successful week!  Gary came up with the idea that anyone working paleo out in the field should take "field selfies".  Lets do this! 

Gary Vecchiarelli
Our friend Donny, who is an intern at the Mesalands Dinosaur Museum, and currently working on phytosaur research!
Christopher DiPiazza (me)
Even paleontologist, Tony Martin, got in on the action from Montana!

That's all for this week!  Be sure to check out our facebook page for even more photos from the trip!  I have a few more videos I may put up there, as well! 

Sunday, July 13, 2014

Geisonoceras: Prehistoric Animal of the Week

This week we will be checking out an invertebrate which leaves behind some of the most beautiful fossils ever!  Enter Geisonoceras!

Life reconstruction by Christopher DiPiazza.

Geisonoceras was a cephalopod mollusk, related to modern octopus, squid, cuddlefish, nautolus, and the now extinct, yet highly successful ammonites.  Like them it would have possessed a soft, muscular body with tentacles and a sharp beak, as well as a hard outer shell.  It was most likely a predator, hunting trilobites and other arthropod prey.  Geisonoceras is a genus that contained many species which spanned over much of the world's oceans in a broad time long before the first dinosaurs, from roughly 460 to 390 million years ago.  This ranged across two two periods in prehistoric times called the Ordovician and Devonian.  The shells of this amazing mollusk range in size from a few inches to several feet long.  The name Geisonoceras translates to "Geison Horn".  A geison is a long architectural structure seen on ancient Greek buldings.  Geisonoceras possessed a long, slender, horn-shaped shell so the name fits! 

A rather large Geisonoceras fossilized shell on display at the Mesalands Dinosaur Museum in New Mexico.  If you look closely you can see that the stand for this fossil also contains smaller specimens within it!

The shell of Geisonoceras was long and pointed, and would have grown with it from birth.  However, the animal only lives in the first few chambers of the shell, as it is divided into walled sections that become more numerous, making the shell longer as the animal ages.  The shell also contained a hollow tube that spanned its length called a siphuncle.  This structure could be filled with water to control the overall density of the animal, allowing it to control its longitudinal movement in the water. 

That is all for this week!  As always feel free to comment below or on our facebook page!  Stay tuned for more coverage of Gary and I's trip to New Mexico for Triassic field work!

References

Walter A Sweet, 1964. Nautiloidea -Orthocerida, Treatise on Invertebrate Paleontology Part K, Endoceratoidea, Actinoceratoidea, Nautiloidea. Geological Society of America and Univ Kansas Press. Teichert and Moore (Eds)