Discoaster is a genus of extinct star-shaped marine algae, with calcareous exoskeletons of between 5-40 μm across that are abundant as nanofossils in tropical deep-ocean deposits of Neogene age. Discoaster belongs to the haptophytes. About 100 species can be recognized.[2]
The International Commission on Stratigraphy (ICS) has assigned the extinction of Discoaster brouweri as the defining biological marker for the start of the Calabrian Stage of the Pleistocene, 1.806 million years ago. ICS has assigned the extinction of Discoaster pentaradiatus and Discoaster surculus as the defining biological marker for the start of the Gelasian Stage, 2.588 million years ago, the earliest stage of the Pleistocene. ICS further assigned the extinction of Discoaster kugleri as biological marker for the start of the Tortonian Stage of the Miocene, 11.62 million years ago.
Some species in this genus include:[2][3][4]
Discoaster is a genus of extinct star-shaped marine algae, with calcareous exoskeletons of between 5-40 μm across that are abundant as nanofossils in tropical deep-ocean deposits of Neogene age. Discoaster belongs to the haptophytes. About 100 species can be recognized.
所謂的盤星石是一種在始新世便絕種的鈣質微體生物。他們是第三紀的指標化石。盤星石的造型像星星,但有四到三十個壁狀結構,上下兩面還不大相同。他們生活在比較溫暖得地方,且在新生代地層上的意義非常重要。
所謂的盤星石是一種在始新世便絕種的鈣質微體生物。他們是第三紀的指標化石。盤星石的造型像星星,但有四到三十個壁狀結構,上下兩面還不大相同。他們生活在比較溫暖得地方,且在新生代地層上的意義非常重要。