New Middle Triassic Bell-Shaped Nassellarian Radiolaria From Alpine And Carpathian Areas
Author
Dumitrică, Paulian
text
Acta Palaeontologica Romaniae
2024
2024-02-11
20
1
51
75
http://dx.doi.org/10.35463/j.apr.2024.01.05
journal article
10.35463/j.apr.2024.01.05
1842-371x
12582776
Humerocyrtis brevithorax
n. sp.
Fig. 9d, d
1
, e;
10b, d
Diagnosis
. Shell dicyrtid and very short consisting of cephalis, the shoulder plus a short portion of its narrowing distal segment. Cephalis with sparse small pores of various shapes bearing a massive and slightly curved conical apical horn and a straight, three-bladed, and well-developed ventral horn. Thorax short, represented especially by its shoulder and a short narrowing distal part. Proximal part wide and short conical bearing large circular or oval pores separated by narrow and irregularly disposed intervening bars. Circumferential ring separating the two parts of the thorax is marked either by a protruding ring, an imperforate zone, or by no special structure. Distal part of thorax is thinner-walled, very short, narrowing very fast, and its pores are smaller and irregular in size, shape and arrangement. Its distal end is usually frayed, as if not finished.
Studied material
.
Four or
five specimens
, two in the
Pelsonian
, one in the
lower Ladinian
from sample
R78
/1, and one (poorly preserved), or two, in sample Rc4
.
Holotype
.
Fig. 9e
,
CRH
,
Cristian
, coll.
MGL
.110296.
Dimensions
. Maximum length of shell without apical horn 80 µm, maximum diameter of thorax 97-112 µm.
Etymology
. From the Latin
brevis
– short and
thorax
due to its short thorax.
Remarks
. This species differs from the other species of this genus by having a very short and narrowing distal part of thorax, a conical apical horn and a three-bladed ventral horn.
Stratigraphic range
. Samples CRH, R78/1 and Rc4, middle Anisian (Pelsonian) to lower Ladinian (Fassanian) of Eastern Carpathians and Buchenstein Formation, Recoaro area, North
Italy
.