Belemnite "squid" with interesting bore hole found in NJ creek

[CityDweller]

Hi TFF,

 

I recently was in New Jersey and stopped by a creek where I found this. This is a part of a belemnite, an extinct order of squid-like cephalopods that existed from the Late Triassic to Late Cretaceous (~214-80 mya); these are common to the NJ area and the NE USA (as well as all over the world).

 

The cone (rostrum) you are looking at was inside the animal and served as part of an internal skeleton-like structure; it also served as a counter-weight while moving in the water. On the cross-section (C & D), notice the radial symmetry which sprouts from a central axis outward, these are made of calcite crystals, deposited in concentric layers as the animal grew. The symmetry runs through the entire cylindrical body to the apex. These animals were very abundant in the sea and they had 10 arms that had hooks on them which they used to catch prey (soft body fossils exist). There is extensive literature on them available.

 

Image C is most interesting, because there is a bore hole on it, something quite commonly found on the exterior shells of clams, etc. I found that according to Seilacher (1969), micro barnacles would often bore holes in dead (and possibly live) belemnite rostrums on the horizontal plane just like this. See: Seilacher, A. (1969). Paleoecology of boring barnacles. Am. Zoologist, 9:705-719. Univ. of Tubingen, Germany.

 

Notice the uniform long shape, the sleekness of this evolutionary mini marvel.... as Dawkins has said, "Science is the poetry of life." 

 

Hope you find this interesting.

 

 

[Darktooth]

This species is Belemnitella americana.

[CityDweller]

Cool, thanks so much, didn't know that.

[Darktooth]

These are especially abundant at Big Brook Preserve. 

[CityDweller]

Yes, that is where I was.

 

Thank you.

[Mark Kmiecik]

Bore hole or siphuncle?

[TqB]

Interesting hole, I haven't seen one like that in a belemnite.  (Not a siphuncle - they run ventrally inside the phragmocone.)

[erose]

1 hour ago, Mark Kmiecik said:

Bore hole or siphuncle?

No siphuncle in those. The siphuncle would have been part of the soft tissue.
 

But it is an unusual boring. it is not uncommon to find belemnites there riddled with sponge borings. This is different. Certainly a “keeper.”

[CityDweller]

Thank you gents.

[Jeffrey P]

Can't say I've ever seen one like that before. Interesting specimen. 

[Mark Kmiecik]

1 hour ago, Jeffrey P said:

Can't say I've ever seen one like that before. Interesting specimen. 

Yes, it is very interesting.

[The Jersey Devil]

Does the hole go through the belemnite’s length?