Rostrum size differences between Toarcian belemnite battlefields

Journal article

Publication Details

Author(s): Costa Rita P, de Baets K, Schlott M
Publication year: 2018
Volume: 21
Pages range: 171-182
ISSN: 2193-0066
Language: English


Body size changes have been reported across
crisis intervals. Belemnites – now considered extinct stem-decabrachians
– have rarely been investigated for this purpose, and the few studies
have resulted in ambiguous outcomes. Here we investigate two Toarcian
belemnite accumulations in southern Germany from a morphometric point of
view with the support of computed tomography data. The aim of this
study is to test whether a difference in size can be observed between
the rostra of the two studied samples, from individual lineage to
community, and which proxy is more reliable. A significant decrease in
median size from the Early Toarcian (Dactylioceras tenuicostatum Zone) to the Middle Toarcian (Haugia variabilis
Zone) is recognized. This is observed at the community level of
organization, considering the whole assemblage, but also within Passaloteuthis–Acrocoelites
lineage, at the genus level. It is also demonstrated that
diameter-based measurements or maximum preserved length are not reliable
proxies for size, and therefore apical length or three-dimensional
approximations, such as the geometric mean or the post-phragmocone
volume, are more advisable. This is especially important when comparing
specimens with markedly different rostrum shapes. Further studies are,
however, still necessary to disentangle the mechanisms behind the
reduction in rostrum size within the Toarcian and their putative
environmental causes.

FAU Authors / FAU Editors

Costa Rita, Patricia
Lehrstuhl für Paläoumwelt
de Baets, Kenneth Dr.
Lehrstuhl für Paläoumwelt
Schlott, Martina
Lehrstuhl für Mineralogie

How to cite

Costa Rita, P., de Baets, K., & Schlott, M. (2018). Rostrum size differences between Toarcian belemnite battlefields. FOSSIL RECORD, 21, 171-182.

Costa Rita, Patricia, Kenneth de Baets, and Martina Schlott. "Rostrum size differences between Toarcian belemnite battlefields." FOSSIL RECORD 21 (2018): 171-182.


Last updated on 2019-04-01 at 09:10