Hey, I’m back home again, and crawling through my mail. While I’m simultaneously trying to recover from a long, long drive, skim through a mountain of mail, and get caught up on essential grading (there are days I’m glad I have three brains), read Circus of the Spineless #8. I will be back in the blogging business sometime soon.
This week’s Friday Cephalopod is reader submitted.
And there’s more at Andre Seale’s gallery!
The Squid blog links to a wonderful National Geographic video of the Humboldt squid. Watch them attack divers! I cheered! Alas, the squid’s efforts to taste monkey meat were frustrated, and the noble beasts have not learned to love the taste of sweet manflesh…yet.
This strange fish is Euphanerops longaevus, which is one of two species of 370 million year old jawless fishes (the other is Endeiolepis aneri, and the paper suggests that they may actually represent differently preserved members of the same species). These are soft-bodied animals that are usually poorly preserved, and are of interest because they seem to have some properties in common with both the lampreys and the gnathostomes, or jawed fishes. Their exact position in the vertebrate family tree is problematic, and the experts go back and forth on it; sometimes they are grouped with the lampreys, sometimes as cousins more closely related to the gnathostomes.
Hey! Coturnix is horning in on my turf, with a link to fornicating devil beetles (these are not popular beasties in my neighborhood—we get swarms of them every summer, crawling through every crevice to invade our house.)
It’s cool to see, but I may have to send a few of the boys over to the quail-man’s house to teach him a lesson. Either that or reconcile myself to the fact that my niche faces growing competition.
It’s all about style. When you’re out and about looking for mates, what tends to draw the eye first are general signals—health and vigor, symmetry, absence of blemishes or injuries, that sort of thing—but then we also look for that special something, that je ne sais quoi, that dash of character and fashionable uniqueness. In humans, we see the pursuit of that elusive element in shifting fashions: hairstyles, clothing, and makeup change season by season in our efforts to stand out and catch the eye in subtle ways that do not distract from the more important signals of beauty and health.
Flies do the same thing, exhibiting genetic traits that draw the attention of the opposite sex, and while nowhere near as flighty as the foibles of human fashion, they do exhibit considerable variability. Changes in body pigmentation, courtship rituals, and pheromones are all affected by sexual selection, but one odd feature in particular is the presence of spots on the wing. Flies flash and vibrate their wings at prospective mates, so the presence or absence of wing spots can be a distinctive species-specific element in their evolution. One curious thing is that wing spots seem to be easy to lose and gain in a fly lineage, and species independently generate very similar pigment spots. What is it about these patterns that makes them simultaneously labile and frequently re-expressed?
We had some rain overnight, and this morning the sidewalk on my way to work was swarming with earthworms and slugs. The slugs here in Minnesota are tiny little pathetic things, unlike the lovely behemoths I grew up with in Washington state, but they’re still cool to see. Anyway, Afarensis led me to this short photoessay about what happens when a hungry slug meets a worm. I am not surprised at all: I’ve seen a few cannibalistic slug feeding frenzies in my time. They’re like the slo-mo sharks of the damp undergrowth.
My pedipalps were slavering at the news of a symposium on spider sex to be held on the Catalan coast of Spain. Ah, if only I had a legitimate excuse (other than prurience) and a budget that could handle the expense…
It’s a busy time for transitional fossil news—first they find a fishapod, and now we’ve got a Cretaceous snake with legs and a pelvis. One’s in the process of gaining legs, the other is in the early stages of losing them.
Najash rionegrina was discovered in a terrestrial fossil deposit in Argentina, which is important in the ongoing debate about whether snakes evolved from marine or terrestrial ancestors. The specimen isn’t entirely complete (but enough material is present to unambiguously identify it as a snake), consisting of a partial skull and a section of trunk. It has a sacrum! It has a pelvic girdle! It has hindlimbs, with femora, fibulae, and tibiae! It’s a definitive snake with legs, and it’s the oldest snake yet found.
