A Unitary Association-based conodont biozonation of the Smithian-Spathian boundary (Early Triassic) and associated biotic crisis from South China
Author
Leu, Marc
Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland
Author
Bucher, Hugo
Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland
Author
Vennemann, Torsten
Author
Bagherpour, Borhan
Author
Ji, Cheng
Author
Brosse, Morgane
Author
Goudemand, Nicolas
text
Swiss Journal of Palaeontology
2022
19
2022-11-22
141
1
1
61
http://dx.doi.org/10.1186/s13358-022-00259-x
journal article
10.1186/s13358-022-00259-x
1664-2384
PMC9681704
36439694
12000082
Novispathodus
n. sp.
A
Figs. 19G, K, O, P, Q
;
20
T, Y, Z
2015
Novispathodus
aff.
Clinatus
Orchard & Sweet
; Chen et al., p. 111, fig. 7, nr. 6 (only).
Number of specimens
.> 10.
Description.
Segminate P
1
element. 6–10 denticles present. Te cusp is terminal and distinctly conical and often more reclined than anterior denticles. Anteriorly, the denticles are almost as high as the cusp and decline gradually towards the anterior end. Te denticles are mostly fused and the cusp is conical or sometimes swollen at mid-height. Te lower margin is straight to slightly upturned in the posterior half. Basal cavity rounded at posterior margin and tapers towards the anterior end. Basal groove runs from the basal pit to the anterior end.
Remarks
. Similar to
Nv
. ex gr.
pingdingshanensis
in size and in its overall morphological outline, but differs by having a conical and terminal cusp. Te denticles are straight, upright to slightly reclined, not recurved as in
Nv. pingdingshanensis
.
In
Nv
.
abruptus
, the posteriormost denticles show a gradual decline that is not observed here. One of the elements illustrated by
Chen et al. (2015)
as
Nv
. aff.
clinatus
seems to fall within the variation of this species although it has more inclined posterior denticles.
Occurrence. In the late Smithian UAZ
7
in
Qiakong, Lilong,
Guangxi
, South
China
(this study).