We are working on belemnite jaws and this lead to the question to size limits in belemnite body size. The largest genus is undoubtedly Megateuthis from the Middle Jurassic.
The largest published record of a rostrum is around 500 mm in length to our knowledge.
In our collection, there is a phragmocone fragment where the largest septum has a diameter of over 130 mm.
However, there are certainly larger rostra and I wonder is one of you knows about much larger ones. A fossil collector owns a rostrum that is about 600 mm long, but I could imagine that this is not the limit yet.
I look for photos of larger rostra and phragmocones to get an idea of the upper size limit.
Thanks for your contributions!
Schlegelmilch (1998) mentions rostra over 800 mm length and phragmocones with a diameter exceeding 200 mm.
There is not only Megateuthis, but also the often forgotten Hibolithes ingens, described by Stolley in 1929 from Timor, which also had a reconstructed rostrum length of about 40 cm, although the published material is only fragmentary. I am not 100% sure but some of the fragments might be even larger in diameter than the largest Megateuthis.
KS
Ah, interesting! Thanks!
I knew that Hibolithes reached over 20 cm, but 40 is quite impressive.
Do you happen to have the pdf?
Ah cool! Thanks a lot! Do you have plate 8 as well?
The specimen on plate 7 does not look like what I know of Hibolithes...
No, unfortunately these were the only parts I copied. The type material, if it still exists, should be in the Naturalis in Leiden, I always wanted to have a look at it but never got to it.
Well, an alveolar slit is clearly visible, so this can be referred to the Belemnopseina but the genus Hibolithes and related genera all ill-defined anyway...
There is so much research that remains to be carried out on belemnites!
Isn't this great!
René, Dirk, Kenneth and me are working on several coleoid papers at the moment...
Here there is a photo of one of the biggest Volgobelus phragmocone (with diameter 15 cm) from the Hauterivian of the Middle Volga region, Russia. However, these were Acanthoteuthis-like belemnites lacking big rostrum
https://www.ammonit.ru/foto/23014.htm
Dear Mikhail,
that is very impressive, thank you very much!
Did you publish this somewhere?
Best wishes,
Christian
We only published figures of the type material of Volgobelus colossicus (Rogov, Bizikov 2006: http://mmtk.ginras.ru/pdf/Rogov,Bizikov,2006_Belemnoteuthis.pdf ), while this specimen is a recent finding by palaeontologist amateur
As update:
I received a photo of a rostrum of Megateuthis measuring about 1 m in length, but it appears likely that this is a composite/ fake.