Gastropods from the Cretaceous-Palaeogene boundary in Denmark
Author
Hansen, Thomas
text
Zootaxa
2019
2019-08-12
4654
1
1
196
journal article
26049
10.11646/zootaxa.4654.1.1
9ce1d103-9234-4fbe-9544-f1c294bb8783
1175-5326
3365803
CFD82CC0-3110-472E-972B-7ADC0C523A04
Genus
Cerithiella
Verril, 1882
Type
species.
Cerithium metula
Lovén, 1846
(designation by
Sars (1878)
when erecting
Lovenella
Sars, 1878
, a name already in use). Recent, Europe.
Remarks.
It was suggested by
Nützel (1998)
that all fossil taxa with a planktotroph multispiral protoconch may have to be assigned their own genus or reassigned to other genera as all extant species of
Cerithiella
are characterized by a lecithotroph larval shell. It is clear that the present definition of the genus is rather wide and it seems plausible that the planktotrophic taxa in general would be closer related to each other than to the lecithotrophic forms. I do not think that there is any basis for a higher taxonomical reassignment of the planktotrophic forms within the cerithiopsids, as was suggested on a tentative basis by
Nützel (1998)
. Actually there are all grades of intermediates between the two groups and even within a single recent species like
Cerithiella metula
(
Lovén, 1846
)
as re-evalu- ated by
Bouchet & Warén (1993)
a surprisingly large variation in the protoconch morphology may be observed, depending on the environment or geographical location.