Thursday, March 22, 2012

Spring break special: ammonites

All kids love ammonites! Apparently including tiny, "delicate" Jurassic lobsters (who may or may not have been sexually mature, we can't tell), who liked to hang out inside ammonite shells. The authors deduce based on the lobsters' body positions that they were in there on purpose -- leading to the wonderful, Dogs-in-Elk-evoking subheading "Decapods in cephalopods" -- but they couldn't tell whether the lobsters were eating yummy dead ammonoid or just found an especially classy burrow to hang out in. (Found via Laelaps.)

Hermit crabs loved ammonite shells, too. Plenty of other [organism] in [organism] goodness here.

Laelaps again: Ammonoid pearls! Sadly there will be no fossilized ammonite-pearl necklaces, since these were the sort of pearl accretions that just result in entombed parasites in the wall of the shell, but that very fact means we can infer coevolution with those parasites over geological time. Lovely.

3D ammonite radula reconstruction (with video!) using an X-ray technique rather than traditional sectioning revealed that the jaws and teeth of the type examined are... pretty wimpy, actually. The original article suggests that the unusual ammonoid jaw assembly is an adaptation to feeding mainly on plankton in the water column.

I don't know of any other animals named after Egyptian gods, unless Hagryphus counts. Plants have at least a couple: Anubias and Serapias.

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