Revision of Mesozoic Myodocopina (Ostracoda) and a new genus and species, Mesoleberis hollandica, from the Upper Cretaceous of Belgium and The Netherlands
Author
Kornicker, Louis S.
Author
Van, Barry W. M.
Author
Bakel
Author
Fraaije, René H. B.
Author
Jagt, John W. M.
text
Zootaxa
2006
1246
15
54
journal article
50616
10.5281/zenodo.172935
9913fef5-73fb-4525-a3a6-63ad2742ea71
11755326
172935
Triadocypris spitzbergensis
Weitschat 1983
a
Fig. 3
L, M
Triadocypris spitzbergensis
Weitschat 1983a
:309
–323, 10 figs.—1983b:127–138.—
Weitschat & Guhl 1994
:17
–31, figs. 1, 9. —
Cohen
et al.
1998
:258
.—
Kornicker & Sohn 2000
:22
.
Holotype
GeologischPaläontologisches Institut und Museum, University of Hamburg (GPIHM), no. 2558.
Type
locality
Sticky Keep Formation, Lower Triassic (
subrobustus
Zone); Flowerdalen,
Spitsbergen
, lat. 78°N, long. 17°E (
Weitschat 1983b
).
Material
No material examined herein.
Distribution
Triassic of
Spitsbergen
.
Diagnosis (from
Weitschat 1983b
)
Myodocopid with carapace 2.9–3.1 mm long; oval in lateral view. With small rostrum and shallow rostral incisur. Posterior margin forming very slight angle at midpoint, but fairly evenly rounded. Left valve overlaps right. Delicate dentition present along dorsal margin of each valve. Ornamentation composed of small, closely spaced pits. Gills welldeveloped, with three lobes on each side. Lateral eye with about 20 ommatidia.
Foreign attachments.
Weitschat & Guhl (1994:17)
described fossil ciliates attached to the body of one specimen.
Comparisons
Carapace differs from that of
M. hollandica
in having a shallower incisure and a different arrangement of central adductor muscle scars.
Remarks
Weitschat (1983a:314)
referred this species to the
Cypridinidae
; however, the presence of five dorsal bristles on the second article of the first antenna indicates that the species belongs in the
Cylindroleberididae
.
Weitschat (1983a:314)
proposed a new subfamily Triadocypridininae
Weitschat 1983a
for
T. spitzbergensis
,
and
Cohen
et al.
(1998
:254, 259) raised the status to family level as Triadocyprididae. The soft parts of
T. spitzbergensis
differ in some respects from those of extant
Cylindroleberididae
(
Cohen
et al.
1998
:258, 259), and the species may be a new family or subfamily. Nevertheless, the senior author believes it conservative at this time to interpret the differences as variations within the
Cylindroleberididae
. Several species known only from specimens without soft parts but with carapaces somewhat similar to that of
T. spitzbergensis
have been referred tentatively to
Triadocypris
.