This picture reminds me of that scene Jim Carey did in Ace Venture: Pet Detective. Except it's a bug coming out of a rock, not a lunatic coming out a rhino.
Have you ever had something in your hand, but you didn't quite grasp what you were holding? Like a child on a farm who scoops up a handful of warm mud only to find out it's not mud that the cow just dropped.
Well, it happens all the time in science, too. Marie Currie and Henri Becquerel didn't know the energetic rocks they handled were deadly poisonous. (heh....where my science geeks at?). And there was one man who held a very important fossil that he didn't realize was as important as it was.
The mans name was Caspar Wistar. And the Wistar Institute in Philadelphia is named after him. So is the climbing vine Wistaria. In the late 1780's, he began his medical practice. And it became clear that he was a very talented anatomist. He quickly built up a reputation in the fledgling country as being one of the preeminent researchers in the sciences. In fact, it was to Caspar Wistar that then president Thomas Jefferson sent his secretary Meriwether Lewis to learn from before he and William Clark led the expedition to explore the newly acquired territories.
But that's not to say Wistar was not capable of an oversight. In the mid 1790's, someone found and interesting object that had been uncovered in a creek bed in New Jersey. It was sent in to Wistar for study, and he could see right away that it was something special. It was a fossilized bone. A large one. So large, in fact, that Wistar knew it didn't belong to any living creature.
But for some reason, Wistar only took a few notes on it. He never formally described it in a paper. And that's too bad. He could have been the first person to describe a dinosaur bone, and therefore, the official discoverer of dinosaurs. The fact that Wistar didn't spend much time on the bone is doubly surprising because at the time America was considered to be a barren wasteland by many European scientists. the fact that no animals larger than a cow were around led people to think there were no natural resources in America. Oh sure, there were moose and elk, but even Europe had moose and elk. Nothing special about that. The disdain for all things found in America even spilled over to the native people. There were scientists in Europe who thought that America was so devoid of needed resources that the native people who lived there were an effeminate race. They lacked the needed resources for the men to be strong and virile. It was even published in several prominent journals that American Indian males were so lacking in testosterone that they actually lactated and helped nurse their young!
So the fact that Wistar didn't do any real research on the bone is surprising. (when evidence was uncovered that large animals used to roam America in large numbers before going extinct, it was used as further proof by some Europeans that America was a dead/dying wasteland). What's even worse is, Wistar shelved his bone, and then promptly forgot about it. And during some cleaning of his storage rooms at some point, he threw it out. Or someone stole it. Or something else happened to it. No one knows. All we know for sure is, later on in his life when dinosaurs started to be discovered, when he went back to find the bone, he could never find it.
So the first dinosaur bone sent in to a scientist for research was also the first dinosaur bone that was lost. Today we're fairly sure that the bone Wistar had was a thigh bone from a plant eating hadrosaur. But we'll never know for sure.
If you haven't been able to guess by now, this is Friday Rocks. This is the day I indulge myself in my hobby of collecting really old rocks with dead stuff in them.
And today I'm going to try to explain something that opponents of evolution like to discuss. And that's eyes. According to evolution, certain body parts like eyes or wings, didn't just show up fully formed. But half a wing is no good for flying. And half an eye can't be of use, so why did it develop? And, they have a point. Half a wing won't allow a creature to fly. But it might be used to slow a fall when jumping. Or it could be used as a bug catcher. And half an eye would be worthless.
But eyes didn't evolve from nothing to the eyes you and I have. And we can thank ancient fossils like trilobites for allowing us to understand how the eye developed. What we see is nothing like what other creatures see. Some creatures see more color than others. Some see more detail. Some can see in the dark.
Trilobites didn't see anything like what most modern creatures see. Theirs were some of the most primitive eyes. They consisted of calcite rods that extended from the exterior of their shell to the interior where they pressed up against receptors in it's primitive brains. And their sight was limited to light vs. dark. To get some sense of how a trilobite saw, close your eyes and look at your computer screen. Then pass your hand in front of your eyes. That's how the earliest eyes saw.
As you can see, (get it?), you can't distinguish much. All you see is a slightly darker spot move in front of you. But imagine if everything else was blind, and you could see shadow. Trilobites used to judge the amount of darkness and it's size to determine what it was. And considering there were several creatures that ate trilobites, you can probably tell, it wasn't the best system. But it was better than nothing.
By studying different species of trilobite, we can see the evolution of their eyes. The went from simple to complex. (well....complex compared to what they were). Where early trilobites may have had 20-30 lenses in each eye, later ones could have several hundred. And more rods allowed for more detail. Think of your closed eyes as two rids. If you have several hundred, you would still see only shadows, but you would start seeing more detail in the shadows. Trilobite eyes also tended to be curved, giving them a wider angle of vision that what humans have.
Other creatures eyes developed slightly differently. But they started basically the same way. Over hundreds of millions of years, eyes developed more and more until we have eyes like the ones modern creatures have.
The trilobite I have pictured isn't one that most people would consider one of my better pieces. It just doesn't look that impressive. And, really, it's not. It's a fairly common species called Flexicalymene. Also, it's enrolled and half stuck in the matrix. But what it does have is, an associated fossil. If you look at the matrix, on the upper right you can see a colony of bryozoans.
But the thing that makes this fossil so nice is, look at the eyes. They are incredibly well preserved. And the glabella, (the round, bumpy part in between the eyes, remember the diagram a few weeks ago?), shows very fine detail. But it was for the eyes that I selected this example. You can clearly see all the individual rods in each eye.
So, while by our standards, this trilobite would be blind, it actually had fairly good vision for it's time.
Next week, I'm going to show you an example of a flying trilobite. So, if that's something you want to see, I guess you're in luck. And it you don't care, well....that makes me sad. But I'll be back Monday with my very first post of the week! Well, that is if I don't post anything on Sunday. And provided I don't respond to Roll Call before it's scheduled to post....WHATEVER!
Don't forget to royally screw yourself out of an hours sleep tomorrow night because we stubbornly persist in observing the archaic and un-needed daylight savings time.