Were nautiloids responsible?

Phil

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
3,034
Studies of predation damage in Palaeozoic brachiopods have uncovered unidentifiable drill holes. Were nautiloids responsible?

Original report
 

Phil

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
3,034
Could well be John. Octopus certainly leave drill holes in shells, I'm not sure how similar the radula was on a nautiloid to that of octopus though. They probably pretty much ate anything smaller than them and scurrying I'd imagine. Ordovician trilobites needed their defensive spines for some reason, and nautiloids were top predator...
 

Jean

Colossal Squid
Registered
Joined
Nov 19, 2002
Messages
4,218
To chip in here (:biggrin2:) those holes look just like the ones we see in bivalves from our local oyster borer (Lepsiella scobina). It just looks gastropodish to me.

J
 

Taollan

Vampyroteuthis
Registered
Joined
Aug 17, 2005
Messages
304
Probably not...

While it could be a nautiloid, The holes don't seem right. Cephalopods drill bivalve shells in order to inject a venom that will kill or atleast nearly kill the animal inside, put them pull the shell and eat from the opened shell. This means that the hole needs to only be a pin prick. drilling as small of whole as you need with a radula will generally produce an oval drill. These holes seem to be more rounded and larger than one would expect from a hole merely intended for venom injection. This appears to be more like a gastropod drill, which feed through the hole rather than pulling the shell. This probably is not gastrood either, however, as drilling gastropods aren't thought to have evolved untill 110 million years ago, formly in the Mesozoic, long after these poor brachiopods met their fate.
 

Architeuthoceras

Architeuthis
Staff member
Moderator (Staff)
Joined
Nov 19, 2002
Messages
2,460

Architeuthoceras

Architeuthis
Staff member
Moderator (Staff)
Joined
Nov 19, 2002
Messages
2,460
AMIKUQ
The Giant Octopus in Prince William Sound & Cook Inlet


Near the bottom of the page above is a sketch of a drill hole made by the GPO, looks a little different than those in the brachiopods. Like Taollan said, just a small penetration of the shell is needed. Since the radula of paleozoic nautiloids was somewhat like ammonoids, and that of ammonoids had a more or less distinct similarity to that of octopods I will stand by my no vote. :smile: unless new data proves otherwise :roll:
 

Jean

Colossal Squid
Registered
Joined
Nov 19, 2002
Messages
4,218
spartacus said:
As between them, Jean & Kevin must pretty much know everything I'm going for "no". Not very scientific I know but I'm oddsing it in light of my ignorance.

Keef

MWAHAHAHAHAHA! fooled you all 'cackle':twisted:

Thanks for the kind words Keef but I actually know very little about these prehistoric beasties I just reckon that hole looks like what our whelks do to our clams!!!

J
 
Top