PHOSPHATIZED STAR-LIKE ORAL DISC OF PUNCTATUS AND ITS FUNCTIONAL MORPHOLOGY FROM EARLYEARLY CAMBRIAN OF SOUTH SHAANXI

The Meishucun stage is the prelude of the Cambrian Explosion. In this prominent stage, rapidly radiating evolution and body-plan innovation took place and different associations of organisms formed. In this paper, several 3D-preserved bizarre star-like fossils with finely preserved soft tissues are reported which were recovered from the Kuanchuanpu Member of the Dengying Formation in South Shaanxi, China in 2003. By functional morphology and analogy with mouthpart of Punctatus, it is shown that this star-like organism resembles the coelenterate in systematic classification with the mouth situated at the centre of the star-like organism. The appearance of coelenterate marks the real beginning of metazoan evolution. Therefore, it has the prominent position in the origin and evolutionary history of organisms. Perhaps the star-like organism represents the early types of coelenterate with original tentacles. These new materials provide new evidence for the origin, evolution and the functional evolution of the metazoan during the early stage of the Cambrian explosion.