by Greg Mayer
The Dinosaur Discovery Museum in Kenosha, Wisconsin, is becoming a hotbed of evolutionary activity. I already posted about their Darwin Day celebrations, and now I want to announce an upcoming event in their Spring Lecture series: Life and Death in a Cretaceous Coastal Swamp by my colleague, Prof. Chris Noto. The lecture is this Wednesday, March 20, at 6 PM, and is free and open to the public. His topic will be his work at the Arlington Archosaur Site in Texas, and I’m sure he’ll include a discussion of his work on the feeding habits of giant Cretaceous crocodiles, which we’ve remarked upon here at WEIT before.
The previous event at the Museum was Women in Science Day, which I unfortunately neglected to announce until the day of the event. There was a good turnout nonetheless, as many people, including lots of kids, came to meet the women scientists and see the special exhibits they had set up. My colleagues Drs. Summer Ostrowski and Natalia Taft , joined by MaryRuth Kotelnicki (a trilobite enthusiast who is an adjunct professor at Edgewood College in Madison) entertained and educated the visitors.
I was pleased to find that some WEIT readers were able to attend Darwin Day, so perhaps with a less tardy notice than for Women in Science Day, some might have a chance to make the upcoming Cretaceous coastal swamp lecture. Kenosha is close to both Milwaukee and Chicago. I’m also glad to report that the cartoon Charles Darwins from Darwin Day, as I thought they would, have become a permanent part of the signage for the main dinosaur exhibit.
Damn. I only saw “Discovery” in the title and assumed that this was about creationists. Only noticed what was going on after becoming increasingly confused by the first paragraph. Isn’t it strange how an innocent word can be ruined?
Hah! So I wasn’t the only one then… 🙂
That makes at least three of us.
That is one helluva “ornamented trilobite”!
Not long ago, I encountered an interesting podcast about the discovery of the largest (known, so far) trilobite fossil, the subtly named “Isotelus rex.” Excellent listening for a walk / drive/ flight.
Who, indeed, doesn’t love a good Cruziana?
Alrightythen. I’ll just provide a link to the podcast, even though it was easy to find using the clues given.
Episode 2: Isotelus rex
There are several podcast episodes at that website that look interesting.
Hmmm, I tried posting a link (to the full page, not just the podcast, because the pictures are worthwhile ; as you obviously think too) ; something must have borked.
re: “Who, indeed, doesn’t love a good Cruziana.” So very true. These big guys would have made traces the width of those from the beautiful Carboniferous arthropod Arthropleura.
BTW, that beautiful “ornamented trilobite” is a Terataspis grandis from the Devonian of New York. His name literally translates to “great monster shield” and he come in at 60cm in length.
You are correct that Isotelus rex is one of our largest known trilobites (at 70 cm), however a larger trilobite species was discovered a few years ago in Portugal. These Portugese trilobites are thought to have gotten up to 90cm in length! The most complete specimen was 70cm in length but it was missing its pygidium. An isolated pygidium of the same species was found and it measured in at 20cm in length! 70+20=90cm!! Isotelus rex, though, still remains the largest complete trilobite fossil.
Here’s the journal article about the Portugese trilobites: Giant trilobites and trilobite clusters from the Ordovician of Portugal.
Gutiérrez-Marco et al. Geology. 2009; 37: 443-446.
Here’s a Nat Geo blurb with a photo of one of the incomplete specimens: http://news.nationalgeographic.com/news/2009/05/090511-giant-trilobites-swarms-picture.html
We’re talking a nearly 3-foot long trilobite! Breathtaking. Life is so amazing.
Looks like a place my children would love to visit. Interesting to see that although Charles Darwin has retained his opposable thumbs, he has apparently lost a digit from each hand through an unexplained evolutionary mechanism.
The alteration in hand morphology is due to a widespread feature of the Toonification process (c.f. Who Framed Roger Rabbit?, in which the hands lose a digit and appear to be covered by white gloves, in most instances. This is the result of an Intelligent Designer hired by the film studio. 😉
Charles Darwin has unfortunately been made to make two mutually contradictory claims about Eoraptor: that it’s a basal sauropodomorph and that it’s the common ancestor of sauropods and theropods. It can’t be both and might be neither. Eoraptor is one of the oldest and most primitive known dinosaurs, so it’s not easy to put into any group. And because it’s so hard to place, it was originally described as a theropod, and later as a primitive saurischian belonging to neither Theropoda nor Sauropodomorpha. Some recent analyses have put it closer to sauropods than to theropods (making it a sauropodomorph), which is way cool because it looks a lot like your basic theropod; but that shouldn’t be surprising, as the theropod-like form is primitive within dinosaurs. And that, as Mr. Darwin says, is great evidence for evolution.
As far as being the ancestor of theropods and sauropods, that’s a problem for two reasons. First, in that case it isn’t a sauropodomorph, hence the contradiction. Second, we have no way of saying that any fossil species is the ancestor of any other; we can’t even tell if fossil species are biological species.
I’m enjoying Rebecca Stott’s “Darwin’s Ghosts: The Secret History of Evolution” at the moment.
Can you post a link here that deals with your first sentence in greater detail? [Darwin’s contradictory claims]
John Harshman didn’t mean Darwin the actual scientist; he meant “cartoon Darwin” in the picture above. Although the phrasing chosen by the sign writer is perhaps not the most felicitous, there’s really nothing contradictory about it. Eoraptor is the most basal sauropod, and thus branched off shortly after the sauropods and theropods split, and is in this sense close to the common ancestor of both sauropods and theropods.
GCM
Thanks Greg for the clarification of the tree. That fantastic Trilobite model had grabbed my attention & so I didn’t read the cartoon Darwin display.
Well, you have a greater tolerance for imprecision (euphemistically applied to statements that are technically just plain wrong) than I do. The difference between “closest ancestor” and “closest to the ancestor” is something I can’t help but point out. Apologies.
Like the difference between “assistant regional manager” and “assistant to the regional manager”. Apparently, I’m David Brent.