Enigmatic Triassic Hellasaur Thursday: Part the, um fourth?, Kyrgyz Kameleon

If you’re hoping to make it into the fossil record, being a small, arboreal insectivore is probably not the best way to go. Forest soils are veritable compost heaps: acidic and crawling with critters and fungi that would happily mill your remains to humus given half a chance. And your scrawny, flexible skeleton is highly unlikely to endure the vicissitudes of long distance transport to some more suitable sedimentary environment.

Of course if you’re reading this blog chances are good that you’ve already been born so it may be too late to fix this. But don’t worry–there is a back up plan: find a lake, and fall in. Hey, it worked for Longisquama and Sharovipteryx, though a case could be made that they would have saved everyone a lot of trouble if they had just rotted on the forest floor like a respectable forest dweller.

The Triassic Madygen Formation of Kyrgyzstan is among the most important sources of Triassic insect fossils in the world (Fraser 2006). In fact, I’d almost rather write about the titanoptera, an “enigmatic” insect group which included the 30-cm wing-spanned Gigatitan vulgaris that may have looked something like the result of an unholy love-affair between a coackroach and a mantis…on crack. But this is “Hellasaur” Thursday so I’d better stay focused.

Left: LANDSAT image of Madygen Formation outcrops - de.wikipedia

In fact, it was the search for insect fossils that led to the discovery of two the Triassic’s more problematic hellasaurs. The first, Sharovipteryx mirabilis, is bad enough, what with its bizarre hind-limb “delta wing” and its purported link to pterosaur evolution despite its patagium-backward construction. We’ll leave Sharovipteryx be for now because our topic at hand is going to require the full bottle of Excedrin.

Longisquama insignis type specimen.

Behold, Longisquama insignis, “remarkably long-scaled” as the rather prosaic scientific name would have it. “Remarkable” is certainly *one* way to describe Longisquama. Whether the protarded 10 to 15 cm long structures which appear to project from its back are scales is (as Zach noted in the comment to a previous post) up for debate.

Some argue that the strange frond-like structures are the foliage of some unknown plant. They do look vaguely vegetative, although other plant matter on the slab appears to show a very different style of preservation and Fraser notes that they have “a peculiar venation pattern that is inconsistent with any known Triassic foliage types. The structures certainly appear to be physically associated with the skeleton itself, and most who have examined the fossil seem to accept that they belong to the skeleton, though the ‘consensus’ ends abruptly there.

One camp holds that they are feathers (which are, of course, modified scales) (Jones et al. 2000)! If this were true it might seriously upset the notion that birds are derived theropod dinosaurs. However, this view is a decided minority and a vast array of other skeletal evidence as well as the preservation of far more convincing feathers on some theropod fossils weigh heavily in favor of the birds-as-dinosaurs hypothesis. That is, unless maniraptoran theropod “dinosaurs” are secondarily flightless birds that merely look like dinosaurs….

Anyway, if the nature of these structures remains contentious, then establishing their function has basically been an interpretive free-for-all. A number of authors have tried to turn them into a parachuting or gliding apparatus of some sort. However, unless they supported a membrane, or were filled with helium, it’s hard to imagine how this would have worked. That said, a recent phylogenetic analysis suggests Longisquama may have been closely related to Coelurosauravus a Permian diapsid with a slightly more (though perhaps not altogether) convincing gliding membrane projecting from its sides.

Left: Longisquama as plumulus glider - Oregon State University.

Display –either to attract mates or perhaps to scare off potential predators or intraspecific rivals—is another popular explanation and probably a more convincing one. Elongate plumes in birds are exclusively a sexual selection affair; in fact their value as a sexual symbol may be directly linked to their hindrance to locomotion.

Scissor-tailed Flycatcher - Tyrannus forficatus

Another, admittedly fanciful, scenario is that the resemblance to a plant frond is not-coincidental. Could the scales of Longisquama be some extreme cryptic adaptation? Perhaps they hid the animal from predators or provided cover allowing Longisquama to ambush its supposed insect prey? Structural mimicry of plants is rampant among arthropods and in addition to more familiar cryptic coloration patterns, a number of land vertebrates use posturing as well as modified skin surfaces to blend into their surroundings

While sexual advertising and cryptic camouflage would appear to be at odds with one another there are animals well-equipped for both. Notably, for our purposes, chameleons, who are at once exceptionally cryptic and at the same time often sport elaborate sexual signaling structures like horns and crests. While chameleons probably don’t adjust their colors to match their background as popularly believed, color switching does allow them to temporarily display their mood to another individual then switch back to their more cryptic “normal” coloration when the mood has passed.

To continue our cautious, chameleon-like walk out on a very thin limb, it’s interesting to note that Longisquama’s skull, as figured by Senter (2004) (shown left), bears a remarkable superficial similarity to that of a chameleon [Note that other, very bird-like reconstructions of the skull out there are probably inaccurate, especially with regards to the supposed antorbital fenestra which is likely a preservational artifact]. The skull of Longisquama’s cousin Coelurosauravus is perhaps even more chameleon like. I’m not prepared to make an argument for functional convergence here, but to me the resemblance is quite striking.

Longisquama is certainly not closely related to chameleons, but its probable close relatives the enigmatic hellasaurs known as drepanosaurs, have been inferred to have had a chameleon-esque lifestyle. One wonders if this interpretation might be extended to Longisquama. Was it lurking in the Triassic treetops, flashing chromatophoric signals across its crazy dorsal scales and snagging titanopterans with a ballistic tongue?

Left: Longisquama by Matt Celeskey

Or, have I just been out in the sun to long?

refs-

Fraser, Nicholas 2006. Dawn of the Dinosaurs Indiana University Press

Jones, Terry D. et al. 2000. “Non-avian Feathers in a Late Triassic Archosaur.” Science 23 June 2000:
Vol. 288. no. 5474, pp. 2202 - 2205 DOI: 10.1126/science.288.5474.2202

Senter, Phil 2004. “Phylogeny of Drepanosauridae (Reptilia: Diapsida).” Journal of Systematic Palaeontology 2: 257-268 DOI: 10.1017/S1477201904001427

Hitting the Proverbial Snooze Button…

Today I was introduced as an ‘up and coming science blogger’ (paraphrasing there). It was like one of those moments where you pass in front of a mirror, catch a peripheral glimpse and think “wait, is that what I really look like?”

So,

Armadillodile wars…Sophophora?…hopeless monsters…anthroposenescence…

Um, I think I’ll sit this year/epoch out, thanks.

(with apologies to Tom Philippi)

Expect more decontextualized photo-collages…ganked media…wild, instantly retracted neologistics…19th century historiographies…maybe some bug sex. In short, we’re gonna party like it’s 2006.

When I wake up that is. If I wake up before the larvae pupate that is.

Until then: check out the best thing ever (thanks to zooillogix and retrospectacle from that one science blog portal…i forget the name).

Putting my photos where my mouth is… (I had to move my foot first)

 

i’ve finally gotten around to putting a Creative Commons license on my Flickr photos.

Appropriate away!

Solstice is Over Man!

So, I won’t waste my time wishing y’all a happy holiday. I converted to animism on I-5 just south of Lodi, beneath a wheeling gyre of White Pelicans. Mahayana blows
dude. Sorry.

Those pelicans then shall be our collective mascot this holy season, their holding pattern a gleaming metaphor for our soul. Which is to say, don’t be surprised if things are pretty quiet around here for the rest of the week.

In the mean time:

- Jennifer Rae Atkins pulled of the astonishing feat of drawing twenty-four mammals in twenty-four hours and in the process raised $800 for Defenders of Wildlife. With the help of several gallons of vanilla DP, she even managed to slam my “diabolical” curve-ball request out of the park. Go check out her awesome work!

- Entomologist, photographer and one-time Davisite, Alex Wild has launched an awesome ant-blog Myrmecos. Wild’s photography is truly amazing and has often made me want to chuck my camera off a cliff. Fortunately, since the camera doesn’t belong to me, there aren’t many cliffs in Davis. His blog may well drive me to lob my laptop into the Interstate though.

- Mechanical insect art by Mike Libby! Crazy…

- Tai’s tales of auspicious animal encounters reveals the patent grayness of my animistic sphere. But I saw an octopus! and cranes! and like, multiple scorpions some of which I held so cut me some slack.

- I was desperately hoping to take up the Schmitz et al. paper in the inaugural issue of Nature Geoscience and the broader issue of the Ordovician radiation and the growing impulse to invoke bolides as a causal agent for all dramatic biotic events… But, well we’re gonna have to wait for that.

So, here’s your homework - “What are the benefits and dangers of applying neoecology notions like disturbance ecology or island biogeography to evolutionary or extinction events in the fossil record?” Write a three to five page review of the issue including at least six primary references and one figure, due January 15th 2008.

okay, we’ll leave it at that, if I haven’t had cause or opportunity to apologize to you in person this year, I’m sorry.  There’s always next year!

An Ordinate Fondness

When asked about what could be learned about the Creator by studying nature, Haldane is supposed to have quipped, “well, dudeski’s got a major hard-on for beetles.” Or something like that. At somewhere better than 350,000 described species (about 40% of all animal species known), and surely many, many more out there waiting to be described, the diversity of beetles is truly astonishing.

Beyond sheer numerical diversity the ecological diversity of the group is impressive. Carnivores, herbivores, fungivores, scavengers and a robust guild of poo-eaters are all counted among their ranks. There are bioluminescent beetles, giant aquatic fish-eating beetles, beetles with elaborate “horns” and beetles that engage in chemical warfare against lazy Victorian schoolboys.

Also, they are really into kinky sex.

How, precisely, beetles got to be so damn diverse has puzzled scientists for since, well, not before time, surely. Flowering plants, climate change and poo have all been fingered as driving forces in beetle radiation. In the latest issue of Science a star-studded crew of established and erstwhile coleopterists once again take up this age-old question in a report titled “A Comprehensive Phylogeny of Beetles Reveals the Evolutionary Origins of a Superradiation.” In an effort to address the mechanisms underlying beetle “superradation!” the researchers assembled a massive cladogram (pictured at the top of this article) which nicely shows how awesome the beetles are compared to a profoundly lame group like, say, the mammals.

Their conclusion? Well, basically, beetles are so diverse because they have radiated into a wide range of ecological niches since the Jurassic while having a high lineage survival (read: low extinction) rate.

Also, they’re into kinky sex. And eating poo.
Well, that ought to be the end of that debate!

postscript: i kid because i care.

A Comprehensive Phylogeny of Beetles Reveals the Evolutionary Origins of a Superradiation

Toby Hunt, Johannes Bergsten, Zuzana Levkanicova, Anna Papadopoulou, Oliver St. John, Ruth Wild, Peter M. Hammond, Dirk Ahrens, Michael Balke, Michael S. Caterino, Jesús Gómez-Zurita, Ignacio Ribera, Timothy G. Barraclough, Milada Bocakova, Ladislav Bocak, and Alfried P. Vogler (21 December 2007) Science 318 (5858), 1913.

[DOI:10.1126/science.1146954]

An amoeba is smaller than a rat

 

Var. self portraits.

 

 

Web 2.0: boon or deathtrap for middling talent?

Range Maps:

stagnating pool of paraconciousness

“Such highly parallel multitasking - institutional paraconsciousness - while clearly limiting inattentional blindness and the consequences of failures within individual workspaces, does not eliminate them, and introduces new characteristic dysfunctions involving the distortion of information sent between global workspaces.”

 

 

 

 

 

 

web, 2.0: Joyous byte-arcade

PERIOD.

trust me, the name of my new band is Croizat and the rad racers.

actually, it’s Tuftian guerrillas of iconography.

as a I said, damnation: , parallel microtextes:

When Animal Memes Attack!

The last time I got tagged with a meme…well Decimating Birds: Episode V is coming any day now. I swear.

Now Brian has tagged me with the “Cool Animal Meme” that’s been racing around the interwebs like a Chinchilla on crystal meth. So…here it goes (I’ve broken things down by vert and invert so I could squeeze a bit more in):

An Interesting Animal I Had
vertebrate:

 

Interesting is certainly one way to describe Clyde. He has acres of personality and makes some of the strangest noises I’ve ever heard come from a dog. Here are three videos of Clyde interacting with a log in Tomales Bay (which he liked), a hawk feather, and a snake skin shed (both of which he did not like).

 

invertebrate:

 

A couple of springs ago I brought in a mantis egg case from the garden and put in on our window sill. I watched it carefully for a couple of weeks then promptly forgot about it. A couple of months later, while enjoying a cup of coffee, I glanced over at the sill and saw this:

I set most of the hatchlings free, but kept one which survived until about Christmas. My manticulture experiments this year didn’t fare so well, I accidentally left the container open and the mantis fled. Oh, well there’s always next year…

An Interesting Animal I Ate
vertebrate:

Okay, this is going to sound weird. Bobcat.  Let me explain (not that it will help)…

When I was a kid my dad hit a bobcat on the way home. Always one to seize an opportunity, my father threw the cat in in the back of the pickup with the idea of salvaging the pelt (which is still around some place). We also got a fair amount of venison this way. My dad also cooked up some of the bobcat meat because, you know, why not?

I don’t remember what it tasted like, but my dad sent me to my mom’s house with a little tupperware of cooked bobcat meat. This of course, totally freaked out my mother (which was surely my father’s intention) but my mom’s pot dealing/gourmet chef landlord raved “It tastes like filet mignon!”

invertebrate:

I’m a bit ashamed to admit that I’ve never intentionally eaten a terrestrial arthropod. We did have an “invertabrate dinner” at the end of my invertebrate biology course but all of the goodies were of the marine and/or molluscan persuasion. I can’t say I’m terribly fond of land snail, but fried conch is delicious.

Probably the tastiest invertebrate eats I’ve had was in El Rocío, Andalucía. After rolling into the dusty Spanish town we parked next to a hitching post and walked down the dirt roads till we found a little tapas bar, complete with horses hitched outside. We ordered up a round chipirones: whole baby squid with garlic and lemon. You had to pick the tiny beaks out of your teeth. Washed down with a cold bottle of Alhambra..yum!

With the prospect of doing field work in Southern China, I imagine my interesting animals I have eaten list is set to grow considerably.

An Interesting Animal In The Museum
vertebrate:

Photo by Sam and/or Sophie from here.

This one’s easy. This juvenile blue whale from the Göteburg Naturhistoriska Museum is surely the most pimped out whale mount on the planet. I tweaked the photo a bit to try to expose the interior a little better, here is how the museum website describes it:

The great blue whale which was preparated in 1865, is exhibited beside its own skeleton and other whales and seals in “Valsalen”. This 15 meter long baby whale is the only stuffed blue whale in the world! Its jaws can be opened, and once a year you can inspect its inside with its wooden floor, flowered tapestry and mahogany benches.

I guess we had good timing because when we visited the whale was open and we climbed on inside, Jonah-style. Being inside a large animal is rather surreal, but I have to say, with the handsome wooden benches and the upholstered walls, the inside of a whale is far cozier than either the Bible or Pinocchio would have you believe.

invertebrate:

Explorit’s giant cave cockroaches (Blaberus giganteus) are pretty fun to share with kids and especially parents. They are much more lively than the hissing cockroaches (though I like them too). They secret a mild vinegary chemical predator deterrent and are freaking huge.

An Interesting Thing I Did With Or To An Animal
vertebrate:

My first ever field biology project at eight or nine, was to tie colored thread to the wrists of toads to try and track their movement and figure out how many individuals were living in our yard. I have no recollection of the results although I do remember recapturing several.

invertebrate:

I’ve done some interesting things to the cave roaches. They have wings but they can’t really fly. However, they can flutter their wings to glide to the ground when tossed in the air. They can also use them to flip back over when they are put on their back. I know, it seems mean, but think about what most people do to cockroaches.

An Interesting Animal In Its Natural Habitat
vertebrate:

Well, I don’t really remember this, but when my parents were first bringing me home from the hospital it was a rainy, bleak day. On the way home they spotted a sodden Golden Eagle walking alongside the road. In true hippie fashion they promptly gave me an ‘indian name’: ‘Walking Eagle.’ Here’s the tattoo I have that commemorates that moment:

A few years ago, when I was working as an intern at Fossil Butte National Monument in Wyoming I had my most memorable Eagle encounter. I was prospecting for Eocene mammal fossils in the Wasatch Formation. As I came over the crest of Cundick Ridge I came face to beak with an Eagle roosting on a rock. I was probably several meters away but it felt like I could have reached out and touched it.

My heart skipped a beat as I stood there awestruck and paralyzed in the presence of this gigantic bird.  After what felt like minutes, but must have been a split second, the eagle casually leapt off the rock into empty space, unfurled its wings, beat them twice and sailed off. It was out of sight in a few moments, replaced by a few stray fluffs of down slowly tumbling down the cliff.

invertebrate:

Again, it’s tough to pick just one.  Finding adult ant lions with kids this spring was pretty awesome.  And lately I’ve become obsessed with scorpion hunting.  Most recently I got a big kick out of seeing an octopus while exploring tidepools in Cambria.  None of the photos turned out really well but this was the best of the lot (its the brownish thing center left).

In that eerie way that often happens with exciting animal encounters, I somehow anticipated the whole thing.  As I watched hermit crabs and bat stars I had this ‘octopodial’ feeling. But I certainly didn’t expect to see one of these cryptic masters of disguise, even though I knew that they were probably around.

I was leaning over to examine a chunk of blueschist or something, when I heard a  sudden squirt and turned to see a fist-sized cephalopod inching away.  It morphed from a deep red, to brown, to almost black then back to brown.  I got a short video, you can hear the excitement in my annoying nasal drone:

I still wish I had picked it up, damn it.

Okay, I spent waay too much time on this.  It seems like everyone and their mom has already picked up this meme.  But I’d be nice to see what Carel has to say after he gets back from his blogging vacation.

Oh yeah and Jessica of the brand new blog Inorganics should give it a shot, although I’m predicting some overlap!