Back
Hystrichokolpoma ellipticum

Hystrichokolpoma ellipticum Matsuoka, 1974

Holotype: Matsuoka, 1974, pl.44, fig.2; Fauconnier and Masure, 2004, pl.38, fig.3
Locus typicus: Fujiwara-cho, Nara City, Nara Prefecture, Japan
Stratum typicum: Early-Middle Miocene

Original diagnosis: Matsuoka, 1974, p.330
Ellipsoidal central body with granular surface, continual beneath processes and thin microgranular outer wall. Processes formed from outer wall and of two types: large ones with trapezoid bases, infundibular to buccinate with slightly denticulate open end, and small slender processes with furcate or bifid distal parts. Tabulation refrected by these processes and shape of small archeopyle typical for this genus; 4", 6", 6g, 5""", 1p and 1"""". Small apical archeopyle with several archeopyle sutures and sulcal notch.

Description: Matsuoka, 1974, p.330:
The present specimens of Hystrichokolpoma elliptica are characterized by infundibular to buccinate large hollow processes and ellipsoidal central body with granular surface. Distal ends of large processes are slightly denticulate and somewhat recurved. The plate 6"" is smaller than the other precingular processes. The posterior intercalary process is also small, oncompletely hollow and distally bifid, and occupies the position between plates 1""" and 1"""". The original sulcal and cingular are rflected by small slender processes which are distally furcate or bifid. The cingular region has about twelve small slender processes and the sulcal region has about six small ones. Its small apical archaeopyle is polygonal and has a small sulcal notch.

Affinities:
Matsuoka, 1974, p.330: This species is similar to H. denticulata in having slightly denticulate distal margin of large hollow processes, but differ from the latter in shape of large hollow ones. Also, this species is distinguished from the other species of Hystrichokolpoma in having infundibular to buccinate large hollow processes, characterisitc ellipsoidal central body and small poligonal apical archaeopyle.
Feedback/Report bug