we return, or rather linger, at Snow Jade Cave with this gorgeous cryptic moth,
resting just outside the ostentatious entrance:
crazed helictites inside,
minor musings on the macrocosm
dead leaf perched outside the lady’s restroom at Snow Jade Cave in Fengdu opens to reveal an aposemiotic [sic] warning.
Rather than bore you with a whole set Chinese lepidoptera, I’ll steal a trick from the picture of the day bloggers and release a steady trickle over the next week or
these words are placeholders
The inside of Snow Jade Cave looks like this:
There are, supposedly, 5 to 8 million species of beetle out there. I saw a mouthful er, handful of them in China.
Unfortunately I have no clue as to the identity of any of them, although this one is clearly a Scarabid.
Here are a few more:
Far more spectacular beetle photos may be found today, and most Fridays, at Myrmecos.
Next week, Lepidopterans?
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?
Or, have I just been out in the sun to long?
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
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!
Get those Boneyard posts in…coming this Saturday!
neil.kelleyca a gmail.com
Also you might want to get a jump start on birthday shopping:
Let’s be honest. For me, every day is “Rockflipping Day.” But, despite being the last, blistering day of my vacation, I found a few moments on September 2nd to turn a few stones in honor of International Rock Flipping Day.
My discoveries were rather pedestrian, no salamanders, no snakes, no scorpions, not even a pseudoscorpion. But, I got a few nice shots nevertheless.
First, a bit about the rocks themselves. At left is rock #1, which observant readers will note has a bit of an anthropogenic look to it. The “anthro” in question is my mother, who has taken up stepping stone manufacture lately. This one consists of four scallop shells, one chunk of chert and sixteen amber glass beads (well, fifteen as one has apparently popped out) set in a round slab of concrete.
At right, rock #2, as extraordinarily observant readers may have noticed is a continuation of the seashell theme, though in this case one with a considerably
more established pedigree. It is a roughly grapefruit-sized fossil oyster, probably Ostrea titan one of the ubiquitous (and consequently very dull) fossils of my childhood.
We’ll do #2 first.
Okay, so this one’s a blatant cheat. Not only is this Pacific Treefrog (Pseudacris regilla) atop the fossil oyster, but I took this photo on Aug. 28th, several days before rock flipping day. But that is the rock I flipped on the 2nd, and there were frogs on and around it then too, so I couldn’t resist.
Many other IRF day participants turned up amphibians (check out the flickr pool). Most amphibians began their life as aquatic larva and, because most need to keep their skins moist in order to survive, the damp undersides of rocks are appealing refugia especially in the heat of a summer day.
Here are some other folks with aquatic roots. At center is a slug, perhaps the Gray Garden Slug (Deroceras reticulatum). He/she (I’m not hedging here slugs are hermaphrodites) belongs to that predominately marine group of delectable gooey animals the molluscs, same as the giant oyster he/she’s hiding under.
Slugs and oysters have followed roughly diametric paths. Oysters bulked up on armor and hunkered down in the ocean perhaps none more so than the massive Ostrea titan. Slugs on the other hand, in a previous incarnation as land snails, set out for shore, grew a lung (the opening to which, known as a pneumostome, is clearly visible in this shot), and reduced the size of their shell until it disappeared altogether. This left them vulnerable to predation and dessication, hence the hiding under the rock in the middle of the day bit.
The isopods off to the right (or if you’d rather, rollie-pollies, sowbugs, pillbugs, woodlice etc.) belong to a predominately marine group, the crustaceans. In fact, they still have gills! This makes them one of the most reliable denizens of moist microclimates, logs, underneath rocks, leaf-litter etc. Hence their place of honor on the IRF logo at top. I’ve written more about terrestrial isopods and the bizarre color-changing infection they get in A Passing Glance.
Myriapods, millipedes and centipedes, are today restricted to land although they had some marine relatives in Paleozoic. They are among the oldest groups of land animals and perhaps the first to work out how to extract oxygen from air directly.
Nevertheless, perhaps in an effort to avoid predators, they still tend to favor secluded environments especially under rocks and leaf litter. This millipede seemed none-to happy to see me and scuttled off before I could snap a decent picture. Others, like the house centipede, actually venture into buildings and cause great distress. Perhaps just to ge back at the rock-flippers.
Distant, uniramian cousins of the myriapods, insects are another decidedly terrestrial group. They’ve been even more bold and successful in their conquest of the land. Even many of the aquatic insects still breathe air, either rising to the surface, trapping bubbles, or growing a snorkel off their back side. This black weevil, probably Otiorhynchus something, might be hiding from predators or it could be recently pupated, laying eggs, or just after my mom’s gardenias.
So Rock #2: three phyla and five classes, six if you count the oyster itself, though at 20 million years dead I’m not sure that you could. Next…
Pretty much the same story over at #1. Lots of isopods…
and an earwig pretending to be an isopod.
Best of all, was this Grass Spider (Agelenopsis sp.) who scores us one more class of soil invertebrate, an arachind. And everyone knows arachnids are the best. Next year I’m going to the foothills or lava beds or Arizona or somewhere with some guaranteed scorpions!
I may be loathed by AP science reporters but I’m a favorite with the Times. Or, rather, this photo of my Marrella splendens tattoo has been marked as a flickr favorite by Times science reporter Carl Zimmer. I’m honored!
Funny things, fossil inkjobs. Tattoos have an aura of permanence, but compared to its subject mine is positively ephemeral. But now, it has achieved cyber-immortality. Well at least until the next mass extinction.
Here’s a creative commons photo of the real deal from wikipedia for comparison, a google image search will turn up many more as well as the Marianne Collins drawing that inspired my badge o’ stem arthropod honor.