Conus yabei (Nomura,
1935)
Descrizione.
Shell
medium in size, narrow and rather elongated, height slightly exceeding 2 ½
times diameter. Spire rather high, considerably concave in lateral view with apex
acute. Whorls 15, apical 2 embryonal, smooth and globular, succeeding ones
angulated at lower two-thirds, finely plicated, or crenulated especially marked
by on surface below angle, lower or most aged whorls flat or sometimes slightly
concave in middle. No spiral lines. Body-wholr almost straight in lateral
profile, peripherial angle acute, smooth, except for a few unequal basal
threads which arecoarser towards lower. Incremental lines fine and not
prominent. Aperture very narrow, sides parallel; inner lip slightly oblique at
base (1).
According
to MacNeil (2), Conus ngavianus, from the Upper Miocene -
Pliocene, which is therefore an older species, is closely related to Conus
yabei, which however has a higher spire. However, I believe that this
correlation is only apparent.
By shape
and coloring, Conus yabei is particularly close to the current species Conus
generalis and in particular to Conus generalis krabiensis, which on
the basis of DNA examination seems to be able to obtain the status of species.
Secondo MacNeil (2), il Conus ngavianus,del Miocene Superiore – Pliocene, che è quindi una specie più vecchia, è strettamente correlato con il Conus yabei, che però ha una spira più elevata. Credo però che questa correlazione sia solo apparente.
Per forma e colorazione, il Conus yabei si avvicina particolarmente alla specie attuale Conus generalis e in particolare al Conus generalis krabiensis, che sulla base dell’esame del DNA sembra poter ottenere lo status di specie.
Epoca: Pliocene (Byoritu Beds)
Località: Taiwan
I due esemplari provengono
da:
·
400 m SE di Zyo-tusyowan, stazione 13,
Tusyo-syo, Byoritu-gun, Sintiku-syu, Taiwan
· 400 m SE della baia di Tongxiao, villaggio di Tongxiao, contea di Miaoli, Hsinchu, Taiwan, stazione n. 13
|
Holotype IGPS n. 52367 (Tohoku Imperial University) - Taiwan 43 mm. (jun.nemoto.a4@tohoku.ac.jp)
Foto by Nemoto Jun, a technical staff of the Tohoku University Museum,
preparing fossil specimens |
|
Paratype IGPS n. 52367 (Tohoku Imperial University) - Taiwan 39 mm. (jun.nemoto.a4@tohoku.ac.jp)
Foto by Nemoto Jun, a technical staff of the Tohoku University Museum,
preparing fossil specimens |
|
Conus generalis regenfussi
mm. 65,7
x 30,7 Filippine [AZRC 551-02] |
|
Conus
generalis krabiensis
mm. 43,8 x 18,6
Thailandia
[AZRC 697-01] |
|
Conus
generalis krabiensis
|
|
|
||
Conus generalis regenfussi mm. 65,7 x
30,7 Filippine [AZRC 551-02] |
Conus
generalis krabiensis
mm. 43,8 x 18,6
Thailandia
[AZRC 697-01] |
Conus yabei 43
mm.
|
Conus yabei 39
mm.
|
This species seems related to Conus kanayai.
Bibliografia