Who ruled the Paleozoic seas? The Eurypterid did!

This is a 380 million year old sea scorpion or eurypterid (Eurypterus sp.) from New York state (left). It one of the thousands of specimens in the invertebrate paleontology collection at the Cincinnati Museum Center. Eurypterids were aquatic predators with paddle-like appendages and spiked claws used for catching prey. Their closest living relatives are the arachnids (spiders, harvestmen, mites and scorpions). Eurypterid fossils are found in Ohio and Kentucky and in many other locations in the Eastern United States and around the globe. Eurypterids are the state fossil of New York state and many fine specimens, like this one in the Cincinnati Museum Center collection, have been unearthed in that region.

Now, being only about 15-20 cm in length, this species may not be that imposing but other eurypterids grew to much larger size. Shown here is another eurypterid specimen in the Cincinnati Museum Center collection, Megalograptus ohioensis, collected in Ohio (right). This fossil dates to about 445 million years ago and consists only of the distal portion of the one of the claws or chelicerae, a little like a lobster claw or that of a modern terrestrial scorpion. This portion of the claw alone is about 2 cm wide and nearly 4 cm long. The spines on the claw likely used for grasping slippery prey items are clearly visible. This fragment obviously came form a much larger animal than the New York Eurypterus specimen, however, size variation in eurypterids doesn't stop here.

In a new paper by Simon Braddy, Markus Poschmann and Erik Tetlle available online in the journal Biology Letters the authors describe a new specimen of the eurypterid, Jaekelopterus rhenaniae. The fossil remains described in the Braddy et al. paper are from an animal nearly 2.5 m long, that's just over 8 feet in length. Not only is this is the largest eurypterid described to date it is the largest arthropod ever. The claws of J. rhenaniae alone were over 40 cm long and lined with long spines. The authors speculate that higher oxygen levels in the paleozoic seas may have contributed to the gigantic size of many arthropods during this time but a lack of large vertebrate predators like marine reptiles may have also been a factor as well because large eurypterids like these went extinct about the time we begin to see large marine reptiles in the fossil record.

Read more about this on NPR and listen to an interview with the authors of the study. Thanks to Brenda Hanke of Cincinnati Museum Center for help on this post.

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Note the URL has changed!

I changed the URL to www.cincyevolution.blogspot.com. Hope everyone thinks it makes more sense than an old user name from a defunct email account!

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Time for a new blog name...

OK, when I made this thing I used a user name from an email account at an old job. Hardly a creative way to make a blog name. I'm taking suggestions for a new name for this blog. If I'm going to change the name I should do it now before too many people start reading it, if that indeed even ends up happening!

I'm thinking the URL name should be www.cincyevolution.blogspot.com. Let me know what you think! As for the blog name I'm open to changing that as well. Maybe the name and the URL should be the same? Don't know. Comments welcome!

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Stakeout vagrant birds beware...

There are few things that birders love more than a rare vagrant bird that turns up at someone's backyard feeder. A rare hummingbird at the backyard feeder of a birder instantly is posted on local birding sites and a steady stream of birders usually follows. Wisconsin recently had a doozy of a vagrant when a Green-breasted Mango (Anthracothorax prevostii) showed up at a backyard in Beloit. The northern limits of the Green-breasted Mango's range is in Mexico and there are only a handful of sightings in the US. After the bird failed to leave in the face of the approaching Wisconsin winter the Humane Society of Wisconsin made a controversial decision and took the bird into it's Milwaukee facility and later transfered the bird to the Brookfield Zoo in Chicago. Should vagrant birds be taken into captivity? After all evolution proceeds by those rare individuals in a population who can move into new environments. With global warming more tropical species will likely show up in temperate regions where they were previously never, or seldom, recorded. Is it up to local zoos and humane societies to take in these vagrants? I'm not sure they should. I guess the lesson is next time you hear about that great, state-record bird hanging out in someone's yard get there quick before the local humane society does!

see more on this story at NPR and the Chicago Tribune.

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Cdesign propentsists...

Not even bill size in Geospiza finches evolves as fast as creationist tactics.

The PBS series NOVA presented an excellent documentary titled 'Judgement Day: Intelligent Design on Trial' outlining the latest in a long list of judicial successes for the teaching of evolution in the United States. The case was the 2005 Kitzmiller v. Dover School District in the US District Court of the Middle District of Pennsylvania presided over by President Bush appointee John E. Jones III. The Dover, PA school board required teachers to present intelligent design (ID) as an alternative to evolution and steered students to the pro-ID text 'Of Pandas and People' of which copies were conveniently donated to the school by an anonymous benefactor.

This case was a triumph for science education. Judge Jones' decision concluded not only that the defendants in the case clearly had a religious agenda in violation to the first amendment establishment clause but also that they concealed this agenda to give the appearance of a secular purpose. Former school board members William Buckingham and Alan Bonsell were found to have lied in their original depositions as to the source of the 'Of Pandas and People' texts. Money for the text was raised in Buckingham's church and essentially laundered through Alan Bosnell's father. Judge Jones' decision however went beyond these particulars and declared that there was no evidence presented during the course of the trial to convince him that ID was a valid scientific pursuit, much less a well supported scientific theory.

Central in this case was the 'Of Pandas and People' text. There are many heroes in this case but perhaps the most damning evidence against the constitutionality of the Dover policy came from Southeastern Louisiana University philosophy professor Barbara Forrest. To demonstrate that the ID approach of 'Of Pandas and People' was truly creationism in disguise and thus in violation of the establishment clause as a public school text the plaintiffs subpoenaed the publishers of 'Pandas' to provide early drafts of the text. Forrest combed over thousands of pages and found that the language of the drafts changed to mesh the religious message with the latest judicial rulings.

For example, in 1987 the US Supreme Court case of Edwards versus Aguillard ruled that a Louisiana statute requiring equal time for "creation science" and evolution was in violation of the establishment clause. Drafts of 'Pandas' prior to the Edwards v. Aquillard ruling used the term "Creator" while post Edwards v. Aquillard "creator" was replaced with more vague and less overtly religious terminology like "intelligent agent". The NOVA documentary highlighted one of the more blatant examples of this "evolution" of creationism in response to the "selection" imposed on the movement by the courts and the US Constitution. In their haste to change the text to less obvious religious terminology to get around legal restrictions the publishers of 'Pandas' left behind some obvious editorial clues to their real goals. Places in the text that previously read "creationists" suddenly in later drafts appeared as "cdesign propentsists" and later as "design proponents". A clear editorial transitional form. Congrats to Dr. Forrest. One could not expect more from even the best paleontologists!

Kitzmiller v. Dover represents a stunning defeat for ID. The strategy of ID as a wedge to move the US from a secular society to one dominated by the particular religious views of a segment of the population is exposed in this ruling. It is also made clear that the acceptance of the science of evolution is not tied to any particular theistic or atheistic belief or political ideology. There could not be a better judge for this ruling. A political conservative appointed by a conservative president.

'Judgement Day: Intelligent Design on Trial' did an excellent job presenting the issues at stake in the Dover case. Ironically one of the quotes that stuck with me from the program was from one of the defendant's attorneys Patrick Gillen of the Thomas More Law Center.

"Does science education have to be so narrow, so technical, so deferential to the existing paradigm that we can't even introduce students to what may be the next great theory" Patrick Gillen - Thomas More Law Center

The answer to Gillen's question is yes. Science is narrow. It is limited to those ideas that are testable against the empirical evidence. The range of scientific theories that should be taught in the public schools is also narrow, restricted to those theories that enjoy the support of the available evidence. As an explanation for the origins of biological diversity evolution has enjoyed the support of the empirical evidence for 150 years. ID has no scientific support and worse yet it is not testable as science. There may very well be a "great next theory" out there but until that theory accumulates some actual support then it has no place in the science classroom.

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Closest living relative of the primates...
Above is a photo of a unique member of the mammal clan, the flying lemur or colugo (Cynocephalus volans) from the collection at the Cincinnati Museum Center. This specimen was collected by former CMC zoology curator Robert Kennedy in 1987 on the Philippine island province of Biliran, the first record of this species for that location. This is the skin of the specimen. The skull and most of the skeleton are in the collection of the Smithsonian Institution. The fur is amazingly soft, a little like rabbit fur, and the digits have big recurved claws that look like those of a cat.

Flying lemurs aren't lemurs at all rather they belong to their own unique mammalian order; the dermoptera. There are only two species of flying lemur in the world and both are found in the tropical forests of South-East Asia. One species, the Sunda Flying Lemur (Galeopterus variegatus), is found on the Indo-Malay Peninsula, Singapore, Sumatra, Java and Borneo while the only other living flying lemur, the Philippine flying lemur (Cynocephalus volans) is confined to the islands of the Philippines. If the lemur misnomer wasn't confusing enough, flying lemurs don't fly either, at least not powered flight like a bird, butterfly or bat. These arboreal mammals can glide from tree to tree much in the same way a flying squirrel does. The limbs are connected by loose folds of skin and when the limbs are outstretched the skin creates a large surface area that provides lift in the same way the stretched out fabric of a kite keeps it aloft. Flying lemurs are mostly active at night and they are herbivorous with their diet consisting mainly of leaves, fruits and flowers.

For a long time the place flying lemurs occupy on the mammal family tree has been a mystery. Most scientists placed them somewhere in between insectivorous mammals, like shrews and moles, and the bats. However, a recent study published in the journal Science by Jan Janecka (Department of Veterinary Integrative Biosciences, Texas A&M University) and his colleagues uses modern comparative genomics to shed light on the evolutionary relationships of flying lemurs. As it turns out, according to Janecka and colleagues, the common name flying lemur is not as far off as once thought. The two extant species of flying lemur are the sister group to all the primates, that is to say that primates as a group and flying lemurs are each others closest relatives. This conclusion was drawn on the basis of DNA sequencing of nearly 14,000 letters in the genetic code from flying lemurs, primates, treeshrews and other mammals. Analysis of these DNA sequences reveal that there are shared genetic mutations in flying lemurs and primates that are not found in other mammalian groups. For example, for a particular gene called TEX2 flying lemurs and all the primates sequenced in this study share a deletion of three amino acids not found in other mammals. Together the combined results from these genetic data suggest that the evolutionary split between primates and flying lemurs occurred approximately 63 million years ago, shortly after the extinction of the dinosaurs.

Does this mean that gliding flight was a trait in the ancestors of the primates? Probably not. It is important to remember that flying lemurs have undergone as much evolution as primates since both split from a common ancestor about 63 million years ago. The specialized characters found in modern flying lemurs evolved over time. Because the closest living mammalian group to the grouping of flying lemurs and primates are the treeshrews, a group who (like primates) do not exhibit the gliding behavior found in flying lemurs, one may conclude that the specialized gliding lifestyle of flying lemurs evolved after their split from the mammalian lineage leading to modern primates.

The Janecka study, and many others like it, emphasizes the power of modern molecular genetics in untangling evolutionary puzzles. Because of their close relationship to the primates flying lemurs have the potential to tell us much about the early evolution of primate genomes, including the human genome.

For additional reading see the news article in PennState Live and the original article in Science.

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That pesky penguin...

With Bailey's help (see yesterday's post) we finally finished that pesky, greasy, old penguin. This is a little penguin (Eudyptula minor) found along the coasts of New Zealand. This species is also called the fairy penguin or little blue penguin for the beautiful iridescent blue plumage on it's back. In the little penguin's native New Zealand it is known for nesting under the porches of homes along the coast. This male specimen died at the Cincinnati Zoo and Botanical Garden where it was part of a long-term captive flock. Preparing a study skin from a penguin carcass was a real challenge and I was lucky to have Bailey's help. Compared to the small songbirds, large aquatic birds like waterfowl and penguins have an enormous layer of fat beneath their skin. Of course this is a great adaptation for the bird as it provides insulation and buoyancy but it is a real pain to deal with when preparing the skin. Fat left in a study skin will gradually seep through making the feathers oily and leaving a greasy stain on any substrate the specimen is left lying on. Hopefully we managed to get enough of the fat from the skin to make it an OK study skin, we'll see. I'm thinking Bailey and I will have to nickname our first penguin study skin "Ol' Greasy"!

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Bird skinning at Cincinnati Museum Center

Bailey McKay (right) Mason Milam (left)

Bailey McKay from the University of Minnesota visited Cincinnati this weekend to help us with some bird skinning work. Today we had a very successful skinning seminar attended by Cincinnati Museum Center (CMC) staff and volunteers and graduate students from the University of Kentucky. We prepared seven specimens today and another five specimens over the weekend, everything from blue-gray gnatcatchers to blue grosbeaks to northern parulas, we even prepared a little penguin generously donated to the museum from the Cincinnati Zoo and Botanical Garden. Skinning seminars will be a regular occurrence at the CMC Geier Center from now on and hopefully Bailey will be back to give us more tips and tricks on turning birds into museum quality specimens. More on the experience with that pesky penguin in the next post...

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