Mollusks from late Mesozoic seep deposits, chiefly in California
Author
Kaim, Andrzej
Author
Jenkins, Robert G.
Author
Tanabe, Kazushige
Author
Kiel, Steffen
text
Zootaxa
2014
3861
5
401
440
journal article
42509
10.11646/zootaxa.3861.5.1
0b368704-d9cc-4a82-8248-bc4c06dcf781
1175-5326
252462
E62DB6C3-0C5F-4898-99C4-1BEC70DD1734
Ascheria
? sp.
(
Fig. 7A–D
)
Description.
Large high-spired shell with remnants of opisthocline axial ribs and/or growth lines. Spiral lirae bestdeveloped on whorl/base demarcation and base. Subsutural constriction developing on the adult portion of the shell. Juvenile whorls unknown unless specimens of Kugler
et al.
(1994) and
Gill
et al.
(2005)
belong to the same species. Protoconch unknown. Aperture drop-shaped.
Material and occurrence.
Four specimens from Joes River Formation (probably Eocene-Miocene),
Barbados
collected by Peter Jung. Three specimens (NMB-H 20154, 20155, 20158) from Loc. 10039 (Joes River, western branch of Spa River, between Spa and Richmond Ridge under oceanic cliff. Joes River mudflow. Marlstone lenses with fossils in pebbly clays. 349 E to Spa windmill) and one specimen (NMB-H 20162) from Loc. 10070 (Joes River mudflows in branches of River S of Bissex Hill).
Remarks.
Additional specimens which may belong to this species are illustrated by
Kugler
et al.
(1984)
and
Gill
et al.
(2005)
as “
Diastoma
sp.” and "Cerithid indet." (
Kugler
et al.
1984
), and as “
Abyssochryssos
sp.” and “zygopleurid sp. B” (
Gill
et al.
2005
). The specimens we examined are only fragmentary and a study of the entire material available from
Barbados
would be necessary for a more accurate taxonomic assessment. The gross morphology of all specimens (especially NMB-H 20154, 20155, 20158) is reminiscent of
Abyssomelania
but the most characteristic feature of
Abyssomelania
, the abyssomelanid riblets is absent in the specimens from
Barbados
. Nevertheless it is possible that the specimen from locality 10070 (NMB-H 20162) belongs to
Ascheria
(
Fig. 7D
) due to the presence of a subsutural constriction, while the specimens NMB-H 20154, 20155, and 20158 from locality 10039 belong to
Abyssomelania
.