The Tangled Bank pt. 89 now up!

The new edition of The Tangled Bank is up at Aardvarchaeology, and don’t forget to get your submissions in for the next edition of The Boneyard coming up this Saturday at Fish Feet.

Photo of the Day: Stranded Jelly

A dead jellyfish, rocking in the surf of Cape May, NJ at about 6 in the morning. Simple, maybe, but it’s still one of my favorite shots from this past summer.

New packaging on an old idea

In 1857 scientist Philip Henry Gosse published a book called Omphalos: An Attempt to Untie the Geological Knot (available online, although be forewarned that it is a very large .pdf), proposing that God had created the world with the illusion of great age, other researchers of his day being deceived into thinking the world was more than 6,000 years old. Today Gosse’s work is largely forgotten, and if Gosse had listened to his friend Charles Kingsley (author of The Water Babies) the book might not have been published at all. When Gosse asked Kingsley to review his book (probably thinking that he’d get a glowing summary from his friend), Kingsley replied;

Shall I tell you the truth? It is best. Your book is the first that ever made me doubt [the doctrine of absolute creation], and I fear it will make hundreds do so. Your book tends to prove this – that if we accept the fact of absolute creation, God becomes God-the-Sometime-Deceiver. I do not mean merely in the case of fossils which pretend to be the bones of dead animals; but in … your newly created Adam’s navel, you make God tell a lie. It is not my reason, but my conscience which revolts here … I cannot … believe that God has written on the rocks one enormous and superfluous lie for all mankind.

[Reproduced from Wikipedia]

Obviously, Gosse published anyway, and although American evangelicals would later suggest that fossils were “tricks of the devil,” no one seems to hold to the strong version of “Deceitful Creation” Gosse advocated. A weak version of Gosse’s ideas continue to survive in Christian apologetics to this day however, and evidence of this can be seen in an article in the Spring/Summer 2007 Harvard Divinity Bulletin entitled “God and Evolution: A New Solution.” The author of the work, Sarah Coakley, sets out to accomplish the following;

First, there is the issue of how we should understand the relation of God’s providence to prehuman dimensions of creation and their development. Second, there is the issue of how God’s providence can relate to the specific arena of human freedom and creativity. Then third, there is the problem of evil, the question of why what happens in the first two realms manifests so much destructiveness, suffering, and outright evil, if God is indeed omnipotent, omniscient, and omni-benevolent.

These are relatively “classic” areas of conflict in the evolution vs. Christian theology culture wars, and I do find it interesting that even modern apologists are doing the best they can to separate man from all other forms of life on earth (primarily through culture since anatomical differences have proven to be poor support for such distinctions). Dealing with the first question, Coakley writes;

As such, God is both “within” the process and “without” it. To put this in richly trinitarian terms: God, the Holy Spirit, is the perpetual invitation and lure of the creation to return to its source in the Father, yet never without the full—and suffering—implications of incarnate Sonship. Once we see the possibility of understanding the contingency of precultural evolution in this way, we need not—as so much science and religion “dialogue” has done in recent years—declare the evolutionary process as necessarily “deistically” distanced in some sense from God. Rather, I propose in contrast that God is “kenotically” infused (not by divine loss or withdrawal, but by effusive pouring out) into every causal joint of the creative process, yet precisely without overt derangement of apparent “randomness.”

Such might qualify as pious prose but it has little actually explanatory power; the references and allusions are more poetic than sharply attuned to the topic at hand. The first section relates to the popular Christian notion of a “God-shaped hole” (ok, ok, take a few minutes to get the laughter out of your system and then continue) in every person’s soul or spirit, attributing a spiritual need to every person on earth. There is no proof at all for such assertions, and so it seems to be a bit of popular Christian doctrine that ties itself to the belief that everyone must be saved by Christ to enter heaven (and who wouldn’t want that? Wait, don’t answer that…).

The second half of the paragraph is where it gets interesting; Gos is infused through “effusive pouring out” (so God is in a liquid state?) into the process of evolution, giving it an orthogenic pathway but still exhibiting randomness and contingency. This is the “weak” version of Gosse’s argument, God being present in the evolutionary process but making it look as if he was not, seeming to take a method once suggested in the show Futurama ; “When you do things right, people won’t be sure you’ve done anything at all.” Things get a bit sillier as the explanation continues;

But how, the skeptic might object, is evolutionary contingency—and genuine human freedom—to be seen as logically compatible with secret divine guidance? The intuition pump I want to propose here is what Peter Geach once called the “chess master model.” The basic idea is this: God is like a chess master playing an 8-year-old chess novice. There is a game with regularities and rules; and although there are a huge number of different moves that the child can make, each of these can be successfully responded to by the chess master—they are all already familiar to him. And we have no overall doubt that he is going to win. The analogy with God and the evolutionary process, or with human freedom, admittedly involves some stretching. For a start, God has created the whole game. Also, God timelessly knows what will happen in any different scenario depending on what moves occur. But there is a crucial difference here between God knowing what will occur and God directly causing what occurs; for in this model the contingent variables and choices occur at the level of secondary causation (albeit undergirdingly sustained and thus primarily caused by God).

I assume the hapless 8-year-old playing chess against God was not Bobbie Fischer (and I thought it was Death who played cosmic chess… oh well). Nevertheless, such reflects another popular Christian notion that God is “in control” and “has a plan” even when it is not apparently so, and you have to beat him in chess in order to get what you want, I mean, you’re at the whim of seemingly undirected events that are in reality being directed, making you generally confused as to what the often-cited “will” of God really is. All of the assertions from the author’s essay operate out of unstated assertions about the definite reality of God (it is considered a given), therefore the history of life on earth must be crammed into tight theological boxes if it is to prevent people from abandoning their faith. It is really nothing more than Gosse’s argument with new paint on it, humanity ever playing the fool because they just can’t win against the omni-present “Chess Master.” Coakley’s discussion of resurrection after death/extinction (?) is also rather odd;

Here, once more, there is an equally seductive modern misapprehension to avert: the presumption that dying, or indeed evolutionary “extinction,” is the worst thing that can happen to anyone (or thing). Again, I would contest the misapprehension. This point is not to be misread as a seeming justification for avoidable suffering, victimization, and abuse; but it is to be heard christologically as an insistence that the deepest agony, loss, and apparent wastefulness in God’s creation may, from the perspective of atemporal divinity (and yet also in the Son’s agony and “wasted” death), be spanned by the Spirit’s announcement of resurrection hope. Evil, from this perspective, is mere absence of good; death is the prelude to resurrection. To be sure, the risk God takes in human “freedom” is the terrible risk that humans announce their false “autonomy” in cruelty and destructiveness. Yet the risk is the only risk out of which the worthiest—and, again, most incarnational—forms of participation in God can arise.

[emphasis mine]

Does this mean that there will be glyptodonts, mosasaurs, and tyrannosaurs in heaven? The extinction alluded to in this paragraph is probably that of Homo sapiens (although I’d be interested to see what the author would have to say about the presence of absence of Megatherium in heaven), again hearkening back to the somewhat scary Christian idea that death is necessary for “true life.” I won’t go into a long rant about the subjective use of “good” and “evil” here (I find the position that evil is merely the absence of good to be absurd), but I will briefly mention the dig aimed at atheists in the 2nd-to-last sentence. Human “autonomy” (as if such a thing had not existed at some point and had been given) is related to destructiveness and cruelty, reinforcing the misapprehension that in the absence of God (=good) there is only evil. Such a statement is patently untrue, even though those who are already inclined to agree with such a statement will nod there heads and move on.

And then I arrived at this bit, which I can only describe as “treacly”;

[I]f by that we mean that God is perpetually sustaining us, loving us into existence, pouring God’s self into every secret crack and joint of the created process, and inviting the human will, in the lure of the Spirit, into an ever-deepening engagement with the implications of the Incarnation, its “groanings” (Romans 8), for the sake of redemption.

So if God stopped loving us, we would cease to exist? Again, the psuedo-poetic religious buzzwords and catch phrases mask any sort of rigorous intellectual understanding of what is being said, but such off-key notes will gain the assent of those who have already trained themselves to respond to them without much further thought.

I will leave the reader of this post to continue on with the initial document if they so choose; I don’t want to spend all my time today pointing out fairly obvious defects within it. I will close by saying, however, that the author of the paper seems to desire a more active God (vs. a more distant God as in deism), found throughout nature but not being apparent, thus allowing Christians a sort of “secret knowledge” not shared by atheists or members of other religions. This approach is often diluted into evangelical techniques, like suggesting that some of the names of God sound like breathing, and therefore even when a atheist breathes they’re speaking the name of God. Such notions may make some people feel warm and fuzzy inside, but it seems to be little more than the construction of a person God that is just active enough to be influential in person life but not enough to intervene when needed the most (tragedy is assumed to be “God’s Will,” any number of reasons being ascribed to a trauma). Indeed, Coakley’s paper puts forth a deceitful and controlling deity that is present in everything but sees fit to let it run riot all the same, and as Laplace once replied to Napoleon on a similar subject “I had no need of that hypothesis.”

The Chimpanzees of Mt. Assirik

When chimpanzees (Pan troglodytes) appear in documentaries they are often shown inhabiting relatively dense tropical forest, their lives taking place within the green refuge of the forests. As with any other species that is spread over a considerable distance, however, different populations of chimpanzees have different habits, and one of the most remarkable populations are those around Mt. Assirik. Located in the southeastern part of the Parc National du Niokolo-Koba in Senegal, the chimpanzees in this area have to deal with a local ecology that is drier and more open than some of their relatives elsewhere, and their behavioral adaptations to the environment is of great interest to those study human origins.

The Mt. Assirik study area is remarkable in that 55% of the habitat is open grassland, only about 37% being woodland of varying density and only 3% being more dense forest (the remaining area being made up of bamboo forest and isolated trees). Such open spaces allow some of the major Carnivora of Africa to live in close proximity to the chimpanzees; Lions (Panthera leo), Leopards (Panthera pardus), Wild Dogs (Lycaon pictus), and Spotted Hyenas (Crocuta crocuta) are all frequently seen in the area. As if having so many predators at their doorstep were not enough, the Mt. Assirik area seems to have fluctuations of food that aren’t correlated with seasonal changes, and in the dry season water is the most prized of any resource. The apes are not entirely helpless in the face of such pressures, however, and they’ve been behaviorally adapted in some very interesting ways.

Given a choice, the Mt. Assirik chimpanzees prefer to spend their time in the denser areas of forest, but shifting food resources sometimes require them to move across large expanses of open grassland in order to find nourishment. Wandering out onto the open plains alone is so dangerous as to nearly be suicidal, and the apes form large mixed groups when they have to move across the plains. During this time they are at their most vulnerable, especially since they would be unlikely to outrun any of the major predators (especially those that hunt in packs), and they are extremely alert when undertaking such a journey. What is perhaps most striking of all, hearkening back to Raymond Dart’s “Savanna Hypothesis,” is the fact that the chimpanzees sometimes stand up to get a better look at their surroundings, potentially spotting predators before they get too close, although such an observation should not be taken as a sweeping vindication of Dart’s ideas of human evolution.

The presence of just one tree or a few trees spaced far apart doesn’t help the chimpanzees much either; mothers with children and individuals spent much less time in the sparser woodland areas than in the forest, mixed groups seemingly having to issues with the woodlands. Why should this be so? Well, leopards can climb trees (and often do so to stash their kills), as well as lions, and so simply climbing a tree does not equal escape. Lone chimpanzees are far more comfortable in a habitat where they can climb a tree and move through the canopy out of reach of their assailants, something that is not possible in woodlands. The predators may also have another effect on the diet of the chimpanzees; the Mt. Assirik chimps do not seem to eat young ungulates or monkeys, although such behaviors have been made famous where it has been observed (i.e. Gombe). This may be due to some competition, but it may also be due to the restricted forested habitat and the fact that chimpanzees would have to enter the habitat of the carnivores in order to capture young ungulates, predators being likely to quickly learn about any kills that had been made.

Indeed, the Mt. Assirik population is remarkable in that it often moves long distances in order to obtain food as it becomes available, relying on numbers and vigilance to protect itself from predators when it’s habitat only offers a few isolated islands of relief. Although humans did not evolve from modern chimpanzees, this population may give researchers some idea of the behavior patterns of our ancestors when faced with similar constraints when forests became sparser and the plains were filled with predators. Such social behavior is not the only thing that makes the Mt. Assirik chimpanzees stand out, however; they also make use of Baobab trees in a very interesting way.

By now many people are familiar with the ability of chimpanzees to use a piece of wood as a hammer to break a nut placed upon an “anvil” of rock or tree root; such footage has been shown in television programs again and again. Such behavior did not come out of nowhere, however, and the way Mt. Assirik chimpanzees open nuts may represent a stage of tool use that precedes the hammer-and-anvil technology. While it had been disputed for some time whether the Mt. Assirik population used hammers and anvils or just anvils, recent studies have shown that they are cracking open the hard nuts of the tree on branches and not using a hammer. While we might think of an “anvil” as something that can only be used in conjunction with a hammer, mechanically this isn’t necessarily so, and the Mt. Assirik chimpanzees bang the hard nuts they collect on the branches of the tree (therefore staying aloft, not coming down to use stones or the roots of the tree), the tree itself being the anvil.

Given the basal usage of anvils by the Mt. Assirik chimps and the use of hammers and anvils elsewhere, it becomes possible to hypothesize about the evolution of stone tool use in our own ancestors. The starting point was likely similar to what is exhibited by the Mt. Assirik chimpanzees, banging hard nuts on trees or rocks in order to open them (thus preventing damage to the teeth, if it even would be possible to open the nuts using their jaws). The next step would be adding a hammer, possibly wooden (as seen in some groups today) or possibly stone. At this stage any combination of wood or stone hammers and anvils could be used, but tool use would probably not progress until a population was using stone hammers and stone anvils to open foods. In such a scenario, the apes would sometimes miss their targets and flake off bits of stone, an accident that would shape the tools. When a certain cognitive leap was made, the apes could then move from accidentally flaking their tools to doing it intentionally to truly be making tools rather than making use of naturally occurring bits of wood and stone. The reality of the situation may be forever lost to us, ancient tool use before the knapping of stone became prevalent being notoriously hard to discern, but such a line of behavioral descent is not unreasonable and seems to allow further development merely by chance combinations of naturally occurring resources.

Such a discussion is only a brief sketch based upon what I have only recently learned myself, but I hope that it has been at least somewhat informative. Different populations of chimpanzees show different behaviors and live in differing ecologies, and it would be a mistake to assume what the famous Gombe chimpanzees are doing holds true for all the other populations. Another population that I soon intend to write about spends time in caves, probes trees for bush babies, and may even have the beginnings of a fire culture; others do not show the same exact behaviors, but they have their own cultures and reactions to the local ecology. While we should be careful in analyzing the living populations of chimpanzees and their perceived similarities to humans, it would be foolish to think that they can tell us nothing of our own past, and if very well may be that some of traits (behavioral or otherwise) they now exhibit were present in our own lineage, vignettes of evolutionary history being replayed with different actors in our own time.

Recycling an old meme

I’ve had this one in my pocket for a bit in case I wanted to write but couldn’t come up with anything original. Pass it along if you like…

If your life was a movie, what would the soundtrack be?
So, here’s how it works:
1. Open your library (iTunes, Winamp, Media Player, iPod, etc)
2. Put it on shuffle/random
3. Press play
4. For every question, type the song that’s playing
5. When you go to a new question, press the next button
6. Don’t lie!
*Optional: Add in a YouTube video or two (if there is one) for some of the songs, or even some sample lyrics to flesh things out a bit

Opening Credits
“The Waiting” – Tom Petty & The Heartbreakers

Waking Up
“The Suffering” – Coheed & Cambria

First Day of School
“Fighting” – Yellowcard

Falling in Love
“Broken Heart” – Motion City Soundtrack

Fight Song
“Angels of the Silences” – Counting Crows

Breaking Up
“Superstition” – Stevie Wonder

Prom
“King of Wishful Thinking” – New Found Glory (originally by Go West)

Life
“Kiss Me Deadly” – Reel Big Fish (originally by Lita Ford)

Driving
“Bad Moon Rising” – Creedence Clearwater Revival

Flashback
“Gimme Some Money” – The Thamesmen (= Spinal Tap)

Getting Back Together
“Learning How to Smile” – Everclear

Wedding
“Slide” – Goo Goo Dolls

Party
“Baby Please Don’t Go” – Aerosmith (originally by Big Joe Williams)

Birth of a Child
“Just What I Needed” – The Cars

Final Battle
“Drones” – Rise Against

Funeral Song
“Gone” – Matt Nathanson

Ending Credits
“Nine Days” – Revolve

Tuesday Morning Notes

So many papers, so little time… Thus far I’ve had a relatively busy start to the semester, especially in terms of having to prepare and give presentations. Every week I have to team up with another student from my Topics in African Prehistory class and present a summation of a few selected papers, and then there’s the new stuff coming out in the journals and what I need to read for my blog posts. Obviously schoolwork gets the priority (expect something about the Mt. Assirik chimpanzees tonight or tomorrow), but I am absolutely inundated by literature as of late.

I also will be giving my Darwin lecture this afternoon, which should be easy enough. I don’t know how much of an interest the students will show, but I’m sure the presentation will come off without any problems. I also want to start planning some talks for Darwin Day (it’s never early to start getting ready) in February, and I really wouldn’t mind being a TA or even teaching a course on evolution if I had the chance. For now, though, I’ll continue to take whatever I can get as far as making presentations, which reminds me I need to resume work on my human evolution review paper.

My trip to Haddonfield this past weekend was a bit of a bust, but I’m going to try to make it down to Big Brook this weekend (or the week after next) in the hopes of having some better luck. Shark teeth and bits of mosasaurs and plesiosaurs show up pretty frequently (Hadrosaurus and Dryptosaurus remains being rarer at the site), but even if I come up with nothing it’ll be a more productive adventure.

I’ve still got posts on juvenile sauropods and the history of Tyrannosaurus cooking, although both are going to require a lot of work and will probably have to wait until I have a weekend (or other time when I have 4-6 hours of free time to work). Even though such posts take a long time to construct, I do enjoy writing them up; I learn a lot more by trying to ingrate various resources to reveal the big picture and presenting it than just reading papers on my own. While such mega-posts have been relatively frequent as of late, I’ll try to keep up with new studies & stories as well, especially given the fact that not everyone has time to read through what I write.

In terms of books, things have slowed down a bit lately. Over the summer I was able to get through a new book every 2-3 days, but now it’s taking a bit longer. Still, I carry books with me everywhere and try to get through a few pages on the bus or before class, and I am definitely enjoying Adrian Desmond’s The Hot Blooded Dinosaurs. It’s a bit dated, but Desmond has an appreciation for the history of the debate as well as for the science, and it has plenty of illustrations to help drive home the points made in the book. I’ve really only started it so I can’t say much about the work as a whole, but the first two chapters were very enjoyable, even if I had heard the stories about Cuvier, Owen, Hawkins, mosasaurs, Iguanodon, etc. a thousand times over.

For now I need to finish up getting ready for the lecture, however, but (as I stated above) I should have something up on chimpanzees that use tools and live near open habitats later this evening.

Of feathers, nests, and dinosaurs

In 2006, researchers Peter Dodson and Steve Wang estimated that perhaps 71% of all the dinosaur genera that ever existed have yet to be discovered, with majority of the genera that we are likely to find potentially being described within the next 100 years. Whether the estimates are correct or not, there can be little doubt that we are in a “Golden Age of Paleontology” (as far as dinosaurs are concerned, at least), the known diversity of dinosaurs increasing at a prodigious rate. While the majority of the as-yet-unknown dinosaurs are still in the ground, we should not forget that the dusty storage rooms of museums and universities can hold startling fossils, too, as paleontological expeditions often collect more than can be carefully studied and described by the scientists. While not a dinosaur, the discovery of the archosaur Effigia okeeffeae from Ghost Ranch, New Mexico in storage at the American Museum of Natural History, has opened many new lines of inquiry for scientists interested in the Triassic. Not all such forgotten fossils need to represent wholly new groups of animals to be significant, however.

It has often been remarked that if the famous specimens of Archaeopteryx from the lagerstatten of Bavaria did not preserve feather impressions, they would have been deigned small theropod dinosaurs (T.H. Huxley was, as far as I am aware, the first to do this, although I do not have the precise quotation at hand). It isn’t surprising, therefore, that this actually occurred several times, the urvogel turning up again in unexpected places. One of the first to come to light was the Teyler specimen, initially discovered in 1855 (five years prior to the discovery of the single feather described in 1861 by Christian Erich Hermann von Meyer). Labeled Pterodactylus crassipes, the fossil would remain “hidden in plain sight” on display in the Teyler Museum in the Netherlands until John Ostrom correctly identified the fossil in 1970. While possibly only a footnote to the larger story, Ostrom’s discovery created a taxonomy problem as well; because the Teyler specimen was older, traditionally the species name crassipes would have priority over lithographica (Pterodactylus obviously not applying because Archaeopteryx was not a pterodactyl). The name Archaeopteryx lithographica had been used prominently in the literature for over 100 years, however, and so (thankfully) the species name of the early bird remained lithographica.

A replica of the Eichstatt specimen of Archaeopteryx, on display at the AMNH.

After Ostrom’s find, other specimens started to appear, often confused with the dinosaur Compsognathus, also known from the Solnhofen limestone of Germany. In 1973 F.X. Mayr discovered what is now known as the Eichstatt specimen, which he sent to Peter Wellenhofer in order to confirm its true identity. Later, in 1988, Wellenhofer himself discovered another specimen that had been labeled Compsognathus in the collection of the former mayor of Solnhofen, and Wellenhofer again ran into Archaeopteryx in 1992 when a smaller specimen came out of the Solnhofen limestone.

Gerhard Heilmann’s exquisite illustration of the Berlin Archaeopteryx from his work The Origin of Birds.

Such confusion between Compsognathus and Archaeopteryx show the importance of careful examination and taphonomy to paleontology, however; the chief reason why several specimens were misidentified was due to their lack of feather impressions. The exquisite preservation that makes the Berlin specimen of Archaeopteryx a work of natural art is even rarer than the collected remains of the genus itself, and a simple matter of burial environment can seemingly make all the difference. Indeed, in an age where feathered dinosaurs continue to astonish scientists and the public alike, the presence of absence of feathers on larger animals can be problematic. While smaller dinosaurs like Sinosauropteryx and early birds like Confusciusornis are often found preserved in ash falls that allow their discoverers to make out their feather coverings, larger animals may not be covered up as quickly or have such fine detail preserved, as seen from the partial skeleton of Gigantoraptor described in Nature earlier this year. While it is not unreasonable to infer that the giant Oviraptor-like dinosaur had feathers covering its body for at least some of it’s life based upon its relationships to known feathered dinosaurs, no hard evidence of feathers was found, so what sort of feathers it had, how much of its body was covered, and other details remain (for the time being) largely unanswerable. In fact, feather impressions associated with Gigantoraptor may never be found, but some new research involving it’s cousin Velociraptor may provide some clues as to whether the large oviraptorid had plumage or not.

The medium-sized theropod Velociraptor was discovered during the famous American Museum of Natural History expeditions led by Roy Chapman Andrews to the “Flaming Cliffs” of Mongolia during the early 1920’s, and the first remains of Velociraptor to be examined gave the researchers the impression that it was capable of catching relatively large, quick prey with its hands. While certainly an impressive dinosaur, Velociraptor was not as popular as it’s dromeosaur relative Deinonychus, although Gregory S. Paul’s popular book Predatory Dinosaurs of the World started the ball rolling to get Velociraptor to be a household name. While Paul’s book was insightful and prescient in many ways (including its depictions of feathered dinosaurs), the taxonomy in the work was a bit strange, lumping Deinonychus under the genus Velociraptor. This wouldn’t have been of much ultimate consequence, except the book was timed just right to have an important influence on Michael Crichton while we wrote the best-selling novel Jurassic Park, the name Velociraptor being attributed to Deinonychus. This tradition was carried on in the blockbuster film adaptation and in two sequels, the name Velociraptor overshadowing Deinonychus in prestige. As mentioned previously, however, despite the taxonomic reshuffling Paul’s book was important as it drove home the evolutionary relationship between dinosaurs and birds, and in recent years many dinosaurs have come out of Asia showing that they were covered in feathers.

The skull of Velociraptor. From Osborn, H.F., et al. “Three new Theropoda, Protoceratops zone, central Mongolia.” American Museum novitates ; no. 144. 1924

So, how can we tell if dinosaurs that were not find with associated feather impressions had feathers or not? Until now, feathers are often implied for dromeosaurs during at least some stage of life due to evolutionary relationships, but a new (albeit short) paper by Alan Turner, Peter Makovicky, and Mark Norell shows that there are osteological features that tell of the presence of feathers. Along the ulna of a Velociraptor specimen from Mongolia, 14 bumps about 4mm apart were found in a straight line along the bone, directly corresponding to the same structures in living birds, the bumps serving as an anchor for the secondary feathers. This is an amazing find, especially since Velociraptor shows the presence of actual feathers, not just the “fuzz” or integumentary fibers seen on related dinosaurs like Sinosauropteryx. I have to admit that I chuckled a little when I saw one reproduction of Velociraptor covered in feathers, arms obscured by secondaries, but now it seems that such a reconstruction is much closer to the truth than the traditional leathery-skinned model. While the authors of the paper do note that some dinosaurs could have had feathers while the secondary feather anchors were absent, the presence of such a trait gives us a new feature of the bone that can be used to determine whether a dinosaur had feathers or not, and I hope a larger re-investigation of the ulnas of dromeosaurs will be undertaken as it could help determine the presence of feathers on species too big to have them properly preserved.

The anchors for the secondary feathers in Velociraptor and a Turkey Vulture. From Turner AH, Makovicky PJ, Norell MA (2007) “Feather Quill Knobs in the Dinosaur Velociraptor.” Science 317(5845):1721.

Still, the question of what was Velociraptor doing with secondary feathers remains. It had previously seemed plausible that many of the non-avian dromeosaurs could have lost some of their feathery coverings, possibly only being covered with feathers as a juvenile. This fossil refutes such a notion for Velociraptor, at least, and secondary feathers could have had any number of uses. While they likely didn’t help much in terms of an individual dinosaur’s thermoregulation, they could have been used for signaling/communication, sexual selection, or been used in the temperature regulation of nests. Personally, I think all these factors could have played a role to a greater or lesser extent, but it is the nest hypothesis that interests me the most.

A non-feathered reconstruction of Troodon on a nest. From Horner, J.R. “Dinosaur Reproduction and Parenting.” Annu. Rev. Earth Planet. Sci. 2000. 28:19–45

Those who know their paleo-history will recall that Velociraptor was not the only new theropod to be discovered by Roy Chapman Andrews and his crew. Oviraptor was also uncovered during the expeditions, and the presence of the dinosaur in association with some of the first-known dinosaur eggs gave paleontologists the impression that the theropod was stealing the eggs (hence the name Oviraptor).

An oviraptorid theropod in a brooding position over a nest. From Clark, J.M., Norell, M.A., and Chiappe, L.M. “An oviraptorid skeleton from the late Cretaceous of Ukhaa Tolgod, Mongolia, preserved in an avianlike brooding position over an oviraptorid nest.” 1999. American Museum novitates ; no. 3265

Such an interpretation was not to last, however. Research by AMNH staff during the 1990’s showed that the “Protoceratops” eggs that H.F. Osborn and other scientists thought Oviraptor was stealing were really Oviraptor eggs to begin with, the embryo of one of the tiny theropods being preserved inside and allowing for identification of certain eggs with a particular variety of dinosaur. This relationship was further strengthened by the analysis of an oviraptorid dinosaur, probably Oviraptor, in a brooding position on top of a nest. The preservation of this specimen indicates that it died on top of the nest and was not deposited on it after being moved from elsewhere, there being little disturbance to the nest and parent overall. While the discovery of such behavior is momentous in and of itself, if we apply the discovery of secondary feathers in Velociraptor to the oviraptorid (a close evolutionary relative) it would seem that the dinosaur was shielding the eggs with the hypothetical feathers. This is still conjectural, and the oviraptorid would have to be closely investigated to determine whether it had secondary feathers or not, but I don’t think it’s out of the question to infer that, should this oviraptorid be found to have secondary feathers, it was fanning them out over its eggs when it died.

An oviraptorid sitting on a nest, reconstructed as Citipati. From Clark, J.M., Norell, M.A., and Chiappe, L.M. “An oviraptorid skeleton from the late Cretaceous of Ukhaa Tolgod, Mongolia, preserved in an avianlike brooding position over an oviraptorid nest.” 1999. American Museum novitates ; no. 3265

Given such bird-like behavior in the oviraptorids, it may come as a surprise to find that non-avian theropod dinosaurs may not have had a reproductive cycle like that of modern birds. In a paper released earlier this year, Gregory M. Erickson and others determined that four oviraptorids and one Troodon-like theropod studied seemed to show a more reptilian mode of growth, in that sexual maturity was reached as growth slowed down. This differs from the reproductive modus operandi of living birds, which grow to full size long before breeding begins. While it seems that the dinosaurs, like living crocodiles, took more than a year to reach adult size but attained sexual maturity as adult size was achieved, living birds show explosive growth rates that allow them to reach adult size in much less than a year, yet they are not sexually mature for some time afterwards. Indeed, in dinosaurs it seems sexual maturity was size-linked, while in birds this relationship was decoupled.

On oviraptorid, Citipati, on top of a nest. From Erickson, G.M. et al. “Growth patterns in brooding dinosaurs reveals the timing of sexual maturity in non-avian dinosaurs and genesis of the avian condition.” Biology Letters Volume 3, Number 5. October 22, 2007

Despite the difference in growth patterns and life cycles, it is starkly apparent that birds evolved from theropod dinosaurs, some of their closest relatives being the dromeosaurids like Velociraptor. The “big idea” of a evolutionary relationship between dinosaurs and birds has been firmly established, but there are many questions that have yet to be resolved. Helping to further clarify the picture of bird evolution, another recent paper by Alan Turner, et al. (also appearing in Science) describes the new dinosaur Mahakala
omnogovae, which shares a number of features with birds but not later dromeosaurs.

Phylogenetic tree of Paraves, taking temporal factors into account and reflecting changes in body size (click for larger image). From Turner, A.H. et al. “A Basal Dromaeosaurid and Size Evolution Preceding Avian Flight” Science 317, 1378 (2007)

What is surprising about Mahakala is its mix of features and it’s small size. For some time one of the big questions of bird evolution has been “Why did relatively large dinosaurs shrink to take wing?” I had always felt that this was putting the cart before the horse a bit, but now Mahakala has offered up fossil evidence that the large size seen in later dromeosaur celebrities like Velociraptor is a derived condition, the common ancestor probably being no larger than Archaeopteryx.

What does trouble me about this find is it’s age; Mahakala is Campanian (83.5-70 mya) in age. As made clear by the temporal arrangement of the phylogenetic tree, this makes Mahakala much older than Archaeopteryx, Confuciusornis, Yixanornis, and other birds. While Mahakala can tell us much about evolutionary history and has shown that troodontids and dromeosaurids shared a common ancestor which in turn shared a common ancestor with birds (helping to explain those nice secondary feather characteristics in Velociraptor), I am more anxious to see if older, Jurassic relatives can be found. The dinosaurs coming out of Mongolia and China are fantastic finds, but I still find the time disparity between Archaeopteryx and its Cretaceous cousins to be irksome. I’m not the first to bring up such issues either, and I have to say that I do agree with the perspective of Peter Dodson; we need to look at the “big picture” if we’re going to figure this out. In a paper entitled “Origin of Birds: The Final Solution?” Dodson writes;

A philosophy of critical realism seems more congenial for analysis of evolutionary biological individuals having a real history [than cladistics alone]. Cladistics uses parsimony as a first principle, which may be rejected on the grounds that nature is prodigal in every regard. Parsimony based on morphology suffices only when there are no other data sets to consider. Cladistics systematically excludes data from stratigraphy, embryology, ecology, and biogeography that could otherwise be employed to bring maximum evolutionary coherence to biological data. Darwin would have convinced no one if he had been so restrictive in his theory of evolution. The current cladistic analysis of bird origins posits a series of outgroups to birds that postdate the earliest bird by up to 80 million years. This diverts attention from the search for real bird ancestors. A more coherent analysis would concentrate the search for real avian ancestors in the Late Jurassic.

As Dodson notes, morphological analysis alone is not going to get the job done, although I was much relieved by the fact that Turner, et al. used a time scale in constructing their tree. Especially concerning birds, I had always wondered why I would occasionally see animations of Deinonychus growing feathers and flying away as a Canada Goose when Arcaheopteryx was much older. It should be noted that Archaeopteryx is the oldest known bird, not necessarily ancestral to all later birds, but I would hope that more focus would be given to the Jurassic in the search for bird origins as I think the most important fossils to the origins of birds are far older than Mahakala. The chief problem with uncovering the most distant past, however, is that factors of taphonomy might inhibit identification of early bird relatives, especially if they are not preserved in lagerstatten deposits. The fine preservation of so many feathered dinosaurs are partially what has made them so popular, and unless fossil beds resulting from ash falls or ancient lagoons are found, the search for the “early birds” may prove to be exceedingly difficult.

The fossil finds recently reported in Science and elsewhere are definitely important, especially since they shed new light on the evolution of birds and of their dinosaurian relatives. Some, however, have greeted the recent studies with groans; hasn’t everyone had enough of feathered dinosaurs? Such attitudes are unfortunate, as there is still much to learn from specimens that have already been known for a long time. Constant revision and careful reanalysis are the bread-and-butter of good science, and I don’t think any generation of workers should be content with saying “It’s been done” and assume that everything they’ve been told previously is still true. This is not a call to develop new hare-brained hypotheses for their own sake, but rather a plea to keep going back to the dusty shelves of museum basements, to take another look at structures that were initially described decades ago, and to try and keep the bigger evolutionary picture in mind in the search for new specimens. There is too much to learn for any one person to take on these tasks on their own, but as a community I think scientists can still make old bones give up new secrets.

References;

Clark, J.M., Norell, M.A., and Chiappe, L.M. “An oviraptorid skeleton from the late Cretaceous of Ukhaa Tolgod, Mongolia, preserved in an avianlike brooding position over an oviraptorid nest.” 1999. American Museum novitates ; no. 3265

Dodson, P. “Origin of Birds: The Final Solution?” American Zoologist. Volume 40, Issue 4 (August 2000)

Erickson, G.M. et al. “Growth patterns in brooding dinosaurs reveals the timing of sexual maturity in non-avian dinosaurs and genesis of the avian condition.” Biology Letters Volume 3, Number 5. October 22, 2007

Horner, J.R. “Dinosaur Reproduction and Parenting.” Annu. Rev. Earth Planet. Sci. 2000. 28:19–45

Nesbitt, S. “The Anatomy of Effigia okeeffeae (Archosauria, Suchia), Theropod-Like Convergence, and the Distribution of Related Taxa.” Bulletin of the American Museum of Natural History. Number 302, Issue 1 (January 2007)

Osborn, H.F., et al. “Three new Theropoda, Protoceratops zone, central Mongolia.” American Museum novitates ; no. 144. 1924

Paul, G.S. Predatory Dinosaurs of the World. Simon & Schuster, NY. 1988

Shipman, Pat. Taking Wing. Touchstone, NY. 1998

Turner AH, Makovicky PJ, Norell MA (2007) “Feather Quill Knobs in the Dinosaur Velociraptor.” Science 317(5845):1721.

Turner, A.H. et al. “A Basal Dromaeosaurid and Size Evolution Preceding Avian Flight” Science 317, 1378 (2007)

Wang, S.C., and Dodson, P. “Estimating the diversity of dinosaurs” PNAS. September 12, 2006, vol. 103 no. 37 13601-13605

8 things about me[me] returns

Mark, of The Divine Afflatus fame, is back, and upon the occasion of his triumphant return has tagged me with the “8 Random Facts” meme. Although I was tagged by Bora back in June, I figured I might as well give it another go, especially since I would hope that there are least 8 more things of potential interest about me.

1) My wife and I drove down to Haddonfield, NJ today to visit the site where Hadrosaurus foulkii was discovered. I’m planning an uber-post about it’s discovery so I won’t go into those details here, but I have to say I was extremely disappointed with the “park.” After driving about an hour, we made our way through the suburban sprawl to a dead end, a commemorative plaque plastered to a rock sitting right across the street from a newly-built house. Thinking there must be something more to see, Tracey and I made our way down the embankment to the fetid, mosquito-infested and trash-ridden streambed below. While the Cretaceous marl was easy to locate, the only thing of note we found was a discarded Sears credit card. Further exploration was blocked by vast pools of stagnant water and the fact that the “park” was a patch of land surrounded by private property, the monotonous whir of a nearby lawnmower letting us know we were practically in someone’s backyard. Rather unfitting, overall, for one of the most important sites in the history of paleontology.

2) I heard the New Found Glory cover of Go West’s “King of Wishful Thinking” yesterday and I can’t get it out of my head (trust me, the NFG version is much improved over the original). The song can be found on the band’s new album From the Screen to Your Stereo II.

3) Although I would have normally waited for the paperback, I purchased the newest Terry Pratchett book, Making Money on Friday and have been reading it aloud to my wife. Although we somewhat fell out of the tradition, for the first 6 months or so of our marriage I’d read some Terry Pratchett to her every night before bed.

4) When I was in preschool I once played a Stegosaurus pitched in battle with Allosaurus during the ever-popular “Dinosaur Night.” While I was expected to lose, at the close of the confrontation I pleaded my case to the parents on scientific grounds that Allosaurus wouldn’t dare try and take down such a large and spiny critter, but my protest ended up being in vain. At least I got some dinosaur-shaped cereal out of it. (My later high school stage appearances included Eugene in Grease!, Mr. Kraler in the Diary of Anne Frank, and Father Drobney in Don’t Drink the Water).

5) Many people once had imaginary friends, but I had an imaginary enemy. Named “Snuff,” he was a demonic, shortened version of Sesame Street’s Mr. Snuffleupagus, and if touched by his trunk you would become paralyzed (and subsequently eaten). You know that high pitched whine you sometimes hear when a television is on even if you can’t see it? I thought that was the sound of his impending arrival, and I once heard it while riding my tricycle in the driveway. I abandoned my vehicle, which my mother ran over while backing out of the driveway, and although I did get in a bit of trouble spare parts were found and all ended well.

6) During the last year of high school and the first years of college I used to frequent the local clubs, seeing a punk/emo/ska band just about every other weekend. The first show I ever went to was for a local group called Shades Apart (they had a song, “Stranger by the Day,” on the American Pie soundtrack), although they are long defunct. The place that I saw them and many other bands, The Birch Hill, was torn down a few years ago, and now most of the shows are at The Starland Ballroom (although I haven’t been there in at least a year and a half).

7) Up until recently I wanted to study marine ecology at Rutgers, specifically what was happening to sharks off the NJ coast (no one seemed to be studying it, given the funding cuts to the EPA, DEP, and Fish & Wildlife in the state). When I told one of my professors about this he replied “What are you ever going to do with that? No one studies sharks” (which was the entire point, from my perspective). Frustrated with the academic wall I kept running into, I ended up taking a course in paleontology & “evolution and geologic time,” which definitely helped establish my current line of interest. Overall, I think I’m better for it.

8 ) This blog, as you and I know it, will soon become extinct. I know I’m using on of the oldest tricks in the book and that I’m terrible because I’m going to leave you all hanging (at least for a little while), but some big changes will soon be going into effect. I think you all will be pleasantly surprised, but for now mum’s the word. In time all will be revealed, but I’ll still be writing regularly until I can divulge the secrets in my possession.

So there you have it, 8 little tidbits of information that may or may not have replaced something more important that you were supposed to remember (i.e. the location of the car keys). Everyone who immediately comes to mind as far as tagging goes has already been tagged previously, so I’ll leave this one open ended; if you feel compelled to write, just leave a comment and I’ll set up the links. And now to finish up the scraps of reading I have left over…

Photos from the AMNH (yet again)

Here are a few of the photos I took today during my visit to the AMNH. I decided to be “adventurous” and take exclusively B&W shots, hoping to better convey the mood of some of the fossils (or their replicas) that I was looking at. I’ll leave you to be the judge as to whether any of them succeeded in giving more life to the old bones than I have been able to do with color photography.

The relatively gracile (at least compared to the specimen on the 4th floor, see below), yet dynamic mount of Allosaurus in the Grand Rotunda of the AMNH.

The skull of the 4th floor Allosaurus, the famous mount being bent over the chewed vertebral column of an Apatosaurus.

Skull of the “Bear Dog” Amphicyon, a member of the Carnivora from the 4th floor mammal halls. Notice the big saggital crest, the placement of the cheekbones further out from the head, and lack of bone that (while typically not closed at the back) would normally surround the eye. This creature would have had an incredibly powerful bite.

Indeed, the skull of Amphicyon reminded me of that of the creodont Hyaenodon. Again, notice the sagittal crest, the cheekbones placed further out from the skull, and the near lack of bone that would enclose the eye. While smaller than the “Bear Dog,” I still wouldn’t want to cross a Hyaenodon on a bad day.

Compare both those skulls with that of the nimravid Hoplophoneus and you’ll see what I mean. Hoplophoneus doesn’t have as prominent a sagittal crest, and although it still seemed to have large jaw muscles, there isn’t the same degree of reduction of bone surrounding the eye as is seen in the previous two mammals.

And, if you like, you can compare them further still with this Smilodon that had broken off it’s left canine. Such occurrences were likely painful, debilitating, and possibly even eventually fatal, and it makes me wonder if this one died as a result of it’s wound or if it continued to survive for some time longer (which opens up all sorts of questions).

A close-up of a more intact Smilodon.

A stuffed Giant Anteater from the Hall of Biodiversity. I much prefer photographing lives xenarthrans, however.

Apatosaurus is the first sight to grace visitors entering the Hall of Saurischian Dinosaurs.

The robust neck of Apatosaurus looms high above.

Casts of the sauropod footprints R.T. Bird found in Paluxy, TX.

Apatosaurus from the rear.

The head of Barosaurus, held up to (perhaps literally) dizzying heights.

One of the forelimbs of Barosaurus, held out threateningly at the Allosaurus in the first photo.

The head of a mini-reconstruction of Barosaurus.

The juvenile Stegosaurus model was pretty impressive, too.

A skull of Camarasaurus.

One of the largest self-contained “bioshpheres” I have ever seen. The little dots are shrimp.

One of the most wonderfully preserved (and in my opinion, publicly unappreciated) skeletons every found; a complete and articulated Corythosaurus with skin impressions, collected from the Red Deer River region of Canada.

A juvenile hadrosaur, probably either Corythosaurus or Lambeosaurus. I ran back and forth looking at skulls to try and figure it out, but the skull of the juvenile is slightly distorted, so (me being without access and a CAT scan at hand) I wasn’t able to confirm or deny my leaning towards my hypothesis of it being a Corythosaurus.

A reconstruction of a Deinonychus skull. I looked at the forearms of the skeleton for signs of feather attachments (as had just been announced for Velociraptor by AMNH scientists) but I couldn’t see any, nor could I get close enough to get a good look.

Outside, one of it’s distant, extant relatives took a sip from a small puddle.

The skull of the synapsid Edaphosaurus.

The toothy jaws of Elasmosaurus.

The famous Giant Squid that spreads its tentacles above the Hall of Biodiversity.

The skull of Gorgosaurus, formerly Albertosaurus (although this specimen was first introduced to me as Gorgosaurus in the first place…)

Perspective on a large, iron meteorite.

One of my most favorite mounts in the entire museum; Prestosuchus.

A close-up of Triceratops.

The most popular dinosaur in the museum, Tyrannosaurus rex.

The crushing jaws of Tyrannosaurus.

A stuffed Leopard, posed over a peacock. This is another animal I would much rather photograph while living.

And last but not least, my little cat Charlotte, silhouetted against the evening light while she watched the birds outside.

Prehistoric Flashback…

Many years ago, I can’t remember exactly when, I spent the majority of a wonderful Thanksgiving Day watching a marathon of dinosaur documentaries on PBS. I do not remember what the series was called, I don’t remember how many of episodes there were, nor do I remember the year they were aired, but I do remember the dinosaur animation. Someone has been kind enough to put some of the paleo-vignettes up on YouTube and it’s definitely a bittersweet experience seeing them again. One the one hand, I loved the show as a kid (my parents had to tear me away from it so the annual consumption of the dino-descendant carcass could begin), but seeing them now nearly resulted on me rolling on the floor laughing. I won’t specifically go into what’s wrong with each of these videos (at least not yet), but it seems to me that the dinosaurs are both new and very old. They’re not waddling about, dragging their tails; they seem very active and dynamic, yet they’re exhibiting behaviors that were in vogue during the Charles R. Knight era (in fact the Tyrannosaurus/Triceratops fight seems to play up the whole “eternal enemies” narrative). I couldn’t help but laugh out loud when I saw Stegosaurus menacingly flattening its plates at the offending Ceratosaurus, but I will leave a fuller discussion of stegosaurs and their armor for another day.

Charles R. Knight’s famous painting of a “duel” between Tyrannosaurus and Triceratops. It is one of the most well-known (if not the most well-known) images in all of paleo-imagery.