Cenozoic Spumellarian Radiolaria With Eccentric Microsphere
Author
Dumitrica, Paulian
Institute of Earth Sciences, Université de Lausanne, Géopolis, 1015 Lausanne, Switzerland; mailing address: Dennigkofenweg 33, 3073 Gümligen, Switzerland
Paulian.Dumitrica@unil.ch
text
Acta Palaeontologica Romaniae
2019
2019-04-25
15
1
39
60
http://dx.doi.org/10.35463/j.apr.2019.01.04
journal article
10.35463/j.apr.2019.01.04
1842-371x
10520604
57C54916-CC13-4BA1-BA82-2A99A822D9D1
Homunculodiscus cauleti
nov. sp.
Figure 2
a-h
Description
. Shell disc-shaped, very thin, consisting of two parallel porous plates interconnected by short transversal bars that, in transmitted light look like black spots. They are either irregularly arranged or, most of them are aligned to form arches or incomplete ellipses around the diploconchal structure. Microsphere small, spherical. Deuteroconcha antapically disposed, usually crescent-shaped. Usually there is another crescent-shaped chamber beyond it. The latter is usually part of an elliptical circle surrounding the diploconchal structure. Pores circular, densely arranged in circular or radial rows, the latter especially toward periphery. These rows may be separated by radial beams prolonged into thin short peripheral spines. Periphery irregular, frayed as if not finished.
Material
.
Eight specimens
, of which four illustrated, in the
upper lower Paleocene
.
Holotype
.
Figures 2b, 2f
, coll.
MGL 103555
.
Dimensions
. Diameter of microsphere 14 μm, of shell 185-224 μm.
Etymology
. The species is named for Dr. Jean-Pierre Caulet who described for the first time the species that will become the
type
species of the genus.
Remarks
. This species seems to be intermediate between
Homunculodiscus nascens
and
H. tainemplecta
(Caulet)
. It has better marked crescent-shaped deuteroconcha and elliptical circles around it than
Homunculodiscus nascens
nov. sp.
Range and occurrence
. Recorded only in the upper lower Paleocene sample
DSDP
21-208-30
CC
, north Lord Hove Rise, southwestern Pacific.