Feathers only rarely fossilize, so the distribution of feathers in dinosaurs is difficult to determine. Sometimes feathers mark the bones, though, and bones do preserve well. Here’s an example: the forearm of a Velociraptor retains an array of small bony bumps evenly spaced along its length. What could they be?
People, don’t do this to me. I’ve got all this work I’ve got to get done so that I’m free to go on a date this evening, and you keep sending me these distractions. Like, for instance, this link to a collection of Marine Invertebrate Video and Film Stock Footage. Cephalopods and nudibranchs and crustaceans and salps, all categorized (there’s even an invertebrate mating category! With 421 clips! It’s free porn!) and with thousands of high resolution videos. The previews are all free, but you can also license HD video of these beautiful action shots.
I will be disciplined, though. I’m closing the web page. I will get my writing done. I will put these links here though, so I can later return to “Brain coral spawning” and “Moray tears arms from octopus” and “Flamboyant cuttlefish feeding” and “Siphonophore With Extending Tenacles”.
Back to work.
Maybe there’s time for “Pelagic Tunicate In The Twilight Zone”?
No. Work. Get things done.
Oh, but I want…!
The vertebrate jaw is a product of evolution — we have a serially repeated array of pharyngeal structures as embryos (and fish retain them in all their bony glory as gill arches), and the anterior most arch is modified during our development to form the jaws. The fact that they’re serially repeated raises an interesting possibility: what if, instead of just the one developing into a jaw, others were transformed as well? You could have a whole series of jaws!
One animal has done exactly that. The moray eel has modified one of the more posterior pharyngeal arches into a second pair of jaws, with a set of muscles that can slide it forward to bite prey already held in the mouth.
Vampyroteuthis gazes at you with its terrible ancient eye…
Close it, please, for the love of heaven, close it!
Admit it: if you were walking along and saw this on the trail, you’d stop and turn back, wondering if Shelob was sneaking up behind you.
I heard a rumor that yesterday was Mrs Tilton’s birthday, so here’s a belated gift: a pretty picture of an exotic Brazilian salticid batting its eyelashes at the viewer.
(Take that, Cute Overload!)
Some of you may have never seen an arthropod embryo (or any embryo, for that matter). You’re missing something: embryos are gorgeous and dynamic and just all around wonderful, so let’s correct that lack. Here are two photographs of an insect and a spider embryo. The one on the left is a grasshopper, Schistocerca nitens at about a third of the way through development; the one on the right is Achaearanea tepidariorum. Both are lying on their backs, or dorsal side, with their legs wiggling up towards you.
There are differences in the photographic technique — one is an SEM, the other is a DAPI-stained fluorescence photograph — and the spider embryo has had yolk removed and been flattened (it’s usually curled backward to wrap around a ball of yolk), and you can probably see the expected difference in limb number, but the cool thing is that they look so much alike. The affinities in the body plans just leap out at you. (You may also notice that it doesn’t seem to resemble a certain other rendition of spider development).
