File talk:Nautilus species shells.png

I have referred the three shells to the three species based on the following features:

• left shell → Nautilus macromphalus, based on the relatively small size and the open umbilicus (not obscured by a callus in contrast to N. pompilius and N. belauensis who share a similar color pattern with N. macromphalus but are often larger, especially N. belauensis)
• middle shell → Allonautilus scrobiculatus, based on the “evolute” coiling and the characteristic color pattern of narrow bands.
• right shell → Nautilus pompilius, based on the relatively large size and the presence of an umbilical callus. The missing bands on the lateral sections of the shell may point towards N. stenomphalus but this species has a smaller mean size than A. scrobiculatus and often misses an umbilical callus. Also, it is said that lateral bands can also be missing in individuals of N. pompilius and that distinction of both species on shell features alone is not possible with certainty. Given its size, it is more likely that this shell belongs to N. pompilius than to N. stenomphalus.

Literature used for identification:

• W. Bruce Saunders (2009): The species of Nautilus. Pp. 35–52 in: W. Bruce Saunders, Neil H. Landman (eds.): Nautilus - The Biology and Paleobiology of a Living Fossil. Reprint with additions. Springer, ISBN 978-90-481-3298-0.

--Gretarsson (talk) 10:50, 7 September 2016 (UTC) (signature subsequently inserted by --Gretarsson (talk) 16:00, 7 September 2016 (UTC))

Upside down

​​ The file shows the nautilus upside-down, surely? Captainllama (talk) 18:10, 8 December 2019 (UTC)

Surely. --Gretarsson (talk) 19:42, 8 December 2019 (UTC)

What a bizarre thing to get irritated over. The nautilus is not something one encounters by routine. As a non-expert the apparently upside down photograph surprised me and, given the close attention paid to it by illustrious experts such as yourself, I raised it as a tentative and respectful question lest I were making some basic laughable error. Well excuse me for my humility and lack of arrogant rudeness! Yes, it was a question, as indeed your preferred form “doesn’t it” would also have been.

So you acknowledged my suspicion was correct while taking the trouble to express your irritation, yet didn’t bother to actually correct the error! Some might find that rather more of an irritant. Captainllama (talk) 17:43, 13 March 2022 (UTC)