Ammonoid habitat depth preferences

Ammonoid habitat depth preferences

Stable isotopes and predation marks shed new light on ammonoid habitat depth preferences

Ammonoids are extinct cephalopods with external shells which predominated in late Paleozoic and Mesozoic marine ecosystems. Habitat depth belongs to crucial parameters of their palaeoecology and is essential for understanding of ammonoid evolution and extinction. In order to reconstruct the habitat depth preferences of a Late Cretaceous scaphitid ammonoid from Poland, we applied a combination of stable isotope data from aptychi (calcitic elements of ammonoid lower jaw) and co-occurring foraminifera with an analysis of predation marks preserved on scaphitid specimens. Our results document a change in depth preferences of the scaphitid studied and suggest that ammonoids could have been more flexible in their depth related behaviour than anticipated.

Work financed by the National Science Centre, Poland (Grant 2015/19/B/ST10/02033)

The inferred shift in habitat depth preferences of Hoploscaphites constrictus along with shallowing of the sea at the Chełm site, Poland.

Positions of studied scaphitids and foraminifera in the water column of the shallowing Maastrichtian sea, based on mean palaeotemperatures gained from δ18O data from their fossils.

 

Machalski, M., Owocki, K., Dubicka, Z., Malchyk, O. & Wierny, W. 2021. Stable isotopes and predation marks shed new light on ammonoid habitat depth preferences. Scientific Reports 11, 22730 (2021). https://doi.org/10.1038/s41598-021-02236-9