Would it be too outlandish to imagine rudists as having zooxanthellate mantle/surfaces just like modern day tridacnids?
Some rudists may have had symbiotic zooxanthellae -- a few species (such as Torreites) had shell shapes that suggest they were maximizing exposure of their mantle surfaces to the light.
Most other rudists didn’t have that sort of morphology, though, so it probably wasn’t a common thing among them.










