New paper out in Geology! Cheilostome bryozoans evolved aragonite skeletons dozens of times during the transition from calcite to aragonite seas, in contrast to other marine calcifiers. Fossil occurrence data corroborate the story and help nail down the timeline. doi.org/10.1130/G537...

We worked out its evolutionary relationships and suggest an origin for this weird beast by an evolutionary lengthening of development, or peramorphosis. Take a read :)

Castaneametra (named for its resemblance to the chestnut) had a record ~1,000 cirri or claw-like appendages on its underside. It's also probably the largest known feather star, and had big internal cavities which we think were adaptations for respiration at large size.

Thanks for sharing, didn't know about his woodturning powers. Just read the story of the MBL group in David Sepkoski's book, includes some funny anecdotes of Raup trying to moderate Schopf the paleo-radical:

A simple ecological drift model captures the relationship between species age and extinction risk, here in graptolites and probably in other groups too. Points toward role for competition in extinction (like Red Queen)