mix fossils

[drbush]

Dear friends can you help me with this?

I went last week to The Aruma mountain looking for fossils and I found allot , it is 17 cm long and 9 cm wide , thin matrix with mixed fossils , could be worms or crinoids? 

It was a surface find under Aruma mountain , 80 km to the North of Riyadh city, the capital of Saudi Arabia.

The area is Cretaceous, Aruma Formation.

 

[Rockwood]

Cornulites ?

It could be way too young for it though.

[drbush]

another view 

[Rockwood]

Could they be hetromorphic ammonites ?

[Scylla]

At first I thought crinoid because I thought I saw segments in the first picture, but the second picture looks like thin walled, hollow tubes without septations. Maybe Tube worms ?

[FranzBernhard]

Your fossils have some similarities to these:

http://www.thefossilforum.com/index.php?/topic/76141-serpulid-upper-creataceous-styria-austria/

But I am not sure, if they really are what I suggested...

drbush, I think I can see some protrusion from the tube walls toward the center? If so, could you please post some of these protrusions in greater detail?
Thanks!
Franz Bernhard

[Innocentx]

5 hours ago, Scylla said:

hollow tubes without septations

I'm wondering if better photos might reveal coral septa.

 

[fifbrindacier]

I think @Scylla's proposition is a good one.

[drbush]

[FranzBernhard]

@drbush, thanks for the additional photos! Unfortunately, I can not see very much.

Would you be so kind to provide dry close-ups of the six items marked with a red x? Maybe then we have a greater chance to say something more definitive.

Thanks!

Franz Bernhard

[Innocentx]

Your latest photos do look like worm tubes as where the tube is broken reveals undifferentiated infill.

 

[abyssunder]

That might be correct.
I don't see branching characters, so I'm leaning toward worm tubes.
I'm taking as reference M. El-Hedeny et al. 2012. Shallow-marine trace fossils from the Callovian-Oxfordian Tuwaiq Mountain Limestone and Hanifa Formations, central Saudi Arabia. Australian Journal of Basic and Applied Sciences 6(3): 722-733 , although the geological age and the location is different.

 

" Polychaetes Tubes
      Fig. 7(D-E)

Material: Eleven specimens (TFCSA 48-58).

Description: solitary, short, straight, nonbranching cylindrical to subcylindrical tube preferentially runs parallel to the bedding plane. Maximum observed length is up to 30.0 mm and diameter varies from 5.0 to 6.0 mm. Burrows are unusually preserved as full relief, having quite distinct prominent wall-like external structure, which is made up of calcium carbonate. Burrow walls are constructed to form growth ring, which are prominent and symmetrical in outline and unequally spaced, while some burrow tubes display faintly developed and widely and unequally spaced rings. Few tubes show smooth exterior surfaces. Internal materials of the burrow fills are massive and structureless and identical to surrounding material. Sometimes these tubes appear as protruding circles or hollow tubes on the bedding planes. "

[drbush]

FranzBernhard ,I hope these close-ups well help 

[FranzBernhard]

Many thanks, @drbush!

Some of them seem to really have some protrusions at the inside. This may be diagnostic, but I don´t know, if some tubeworm can have these. But overall, worm tubes are still the best option for these.

@abyssunder?

Franz Bernhard

[Innocentx]

19 hours ago, abyssunder said:

Sometimes these tubes appear as protruding circles

I'm seeing that.

[abyssunder]

I haven't a better idea than worm tubes.