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

 


 

 

 

Conus yabei

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

Conus yabei

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.

 

 


Bibliografia

 

 

·         (1) – Nomura, 1935 “Catalogue of the Tertiary and Quaternari mollusco from the island of Taiwan (Formosa) in the Institute of Geology and Palaeontology, Tohoku Imperial University, Sendai, Japan”

·         (2) – MacNeil (1960) “Tertiary and Quaternary Gastropoda of Okinaua”