A fossil genus of the family Uminalidae in the class Gastropoda of the phylum Mollusca. A snail that lived in the inner bays of warm seas. The shell is thick and somewhat large, with prominent spines and spiral ribs on the surface. The outer lip of the shell is thick and spreads outward, with a notch above it. This part forms a notch zone that continues to the upper spiral layer. It has a distinctive axial fold. It is found in the Neogene and Miocene strata in various places from Japan to Southeast Asia and Myanmar, and is considered an index fossil. (→Moon's Hands Down) Source: Encyclopaedia Britannica Concise Encyclopedia About Encyclopaedia Britannica Concise Encyclopedia Information |
軟体動物門腹足綱ウミニナ科の化石属。温暖な海域の内湾にすんでいた巻貝。殻は厚くやや大型で,表面には著しい棘状突起と螺肋がある。殻口外唇は厚く外側に広がり,その上方に切れ込み口がある。この部分は切れ込み帯となって上のほうの螺層まで続いている。特徴ある軸褶がある。日本から東南アジア,ミャンマーにいたる各地の新第三系中新統に産し,示準化石とされる。(→月のおさがり)
出典 ブリタニカ国際大百科事典 小項目事典ブリタニカ国際大百科事典 小項目事典について 情報 |
<<: Photoexcitation - Hikarireiki
>>: Chromulina rosanoffii (light algae) - Chromulina rosanoffii
Born: December 29, 1921, Velika Drenova, Kingdom o...
[1] [noun] ① the origin or beginning of something....
…Also called Wolfram. In the old days, when tungs...
This Buddhist temple is considered one of the fiv...
...The fact that it lasted for a period of 10 yea...
A Japanese musical instrument. It is also written ...
A hero of Greek mythology. Son of Apollo and Epika...
A town in Kamo district in southern Gifu prefectur...
"From changing the color of Juban's colla...
The first head of the Taru family, town elders of...
〘 noun 〙 A building where people live. A house. A ...
…the name of a group of plants that lived only du...
...In China, gagaku means "music of elegance...
…The line spanned the former German and Prussian ...
...Other authors include E. G. Speare, who wrote ...