New data on the Permian ecosystem of the Rodez Basin: ichnofauna (traces of protostomians, tetrapods and fishes), jellyfishes and plants from Banassac-Canilhac (Lozère, southern France)
Author
Moreau, Jean-David
Author
Gand, Georges
text
Geodiversitas
2022
2022-11-10
44
31
975
987
journal article
191623
10.5252/geodiversitas2022v44a31
59cbff56-4af5-4719-9f80-f8a8812265c6
1638-9395
7342122
urn:lsid:zoobank.org:pub:008AF7BE-28B6-4FB5-A007-45BAB4337BAC
Medusina atava
(Pohlig, 1892) Walcott, 1898
(
Fig. 3A, B
)
MATERIAL EXAMINED.
—
One specimen; M486_
2022.1.9
.
DESCRIPTION
The specimen is umbrella-shaped and
16 mm
in diameter. The velum is locally visible, forming an up to
3.3 mm
wide marginal thickening. The jellyfish bears 10, thin, quite straight and radially arranged furrows originating from the centre and corresponding to radial canals (
Fig. 3A, B
). Most furrows join the periphery of the jellyfish. The centre of the jellyfish shows an up to
8 mm
wide, star-shaped and concave structure corresponding to the manubrium (
Fig. 3A, B
).
REMARKS
Medusina atava
was reported in Permian deposits from
France
(
Gand
et al.
1996
),
Germany
(
Schüppel 1984
) and
Italy
(
Ronchi & Santi 2003
). In the Saint-Affrique Basin, both species
Medusina atava
and
Medusina limnica
Müller, 1978
are known from some Permian sites (
Gand
et al.
1996
). However,
Medusina
is for the first time reported in the Permian deposits of the Rodez Basin.
M. limnica
is mainly distinguished from
M. atava
by showing a maximum of four radial canals. Amongst
M. atava
the number of radial canals is variable and can reach a number of ten (
Schüppel 1984
;
Gand
et al.
1996
).