Multiple colors, shapes and sizes (species?) of tube worms

[Lone Hunter]

This might be as interesting as it gets as far as worm tubes, so my question is if they are just tube casts why don't they all look the same? I have only found ones that are usually all greyish and look the same, these almost look like actual worms. Would different species have different tubes?

[JohnJ]

@erose

[Rockwood]

I'm not even going to attempt to assign colors, but maybe the smaller ones are steinkerns, and the larger body fossils. Sometimes they get filled. Sometimes they don't.

[hemipristis]

different generations (i.e., one species atop another) ? 

[erose]

There certainly are many different types of shell-forming worms.  The common catch all has been the genus Serpula. But describing or labeling these as Serpulids is probably better.  And to be clear these are body fossils. They represent a shell created by the original critter not a steinkern or mold.  Most of them grew attached to some sort of shell or hard ground.  But there are also forms like Hamulus that lived free on the substrate.

 

One of the more interesting things we find here in the Cretaceous of Texas are Serpulid tubes attached directly to steinkerns.  This suggests that the steinkern was formed before the worm attached.  The question is are we seeing a fossil form that attached to what was already a fossil? Again totally hard to get your head around until we begin to understand what deep time really means.

[Rockwood]

5 minutes ago, erose said:

One of the more interesting things we find here in the Cretaceous of Texas are Serpulid tubes attached directly to steinkerns.  This suggests that the steinkern was formed before the worm attached.  The question is are we seeing a fossil form that attached to what was already a fossil? Again totally hard to get your head around until we begin to understand what deep time really means.

The preservation that I've noticed made me wonder about something along those lines, but I wasn't quite able to articulate the thought.