Early-Middle Ordovician cephalopods from Ny Friesland, Spitsbergen - a pelagic fauna with Laurentian affinities
Author
Kröger, Björn
72F166B6-51DC-4DD8-9DEE-47EDDEE3D2F2
Finnish Museum of Natural History, University of Helsinki, PO Box 44, FI- 00014 Helsinki, Finland.
bjorn.kroger@helsinki.fi
Author
Pohle, Alexander
9C9B621D-7A77-41FF-8B63-DD21BEE10B56
Paläontologisches Institut und Museum, University of Zurich, Zurich, Switzerland.
alexander.pohle@pim.uzh.ch
text
European Journal of Taxonomy
2021
2021-12-20
783
1
1
102
http://dx.doi.org/10.5852/ejt.2021.783.1601
journal article
2884
10.5852/ejt.2021.783.1601
aa9de9bf-dea4-4321-a51d-6c4f1f55032d
2118-9773
5793422
071EAD63-05ED-4D6C-AC45-8719E6D79E0B
Family
Estonioceratidae Hyatt
in Zittel, 1900
Gen. et sp. indet. A
Fig. 45E–F
Material examined
Specimen
FMNH-P30342
, from
Profilstranda
section,
Ny Friesland
,
Svalbard
,
bed PO 7.5,
4.5 m
above base of Olenidsletta Member
,
V1
a trilobite zone
,
Blackhillsian
,
Floian
.
Description
The specimen is a slightly curved, ca
19 mm
long part of a body chamber, with a circular conch cross section with a diameter of
10.5 mm
at the position of the last septum and
11 mm
at the adoral end. The body chamber is simple conical, without constriction, and with a very shallow hyponomic? sinus at the concave side of the curvature. The conch surface is nearly smooth, ornamented only with very fine directly transverse growth lines. The shell is relatively thick,
1 mm
at the base of the body chamber. The suture is directly transverse, and the septum has a concavity of ca
1.5 mm
. The septal perforation is ca
1 mm
in diameter and positioned ca
0.5 mm
from the convex margin of the conch.
Remarks
The body chamber is strongly curved but lacks an impression zone, and with the exception of the last septum the phragmocone is not preserved, which shows that the curvature is exogastric and the siphuncle is positioned close to the conch margin. The available characters indicate that the fragment is part of an estonioceratid, but a more specific determination is impossible with the material at hand.