Spongioradsia
Encyclopedia
Spongioradsia is an extinct of polyplacophoran
mollusc. Spongioradsia became extinct during the Oligocene
period.
Chiton
Chitons are small to large, primitive marine molluscs in the class Polyplacophora.There are 900 to 1,000 extant species of chitons in the class, which was formerly known as Amphineura....
mollusc. Spongioradsia became extinct during the Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
period.