| 名稱 耙牡蠣化石 | Name Rastellum |
| 地質年代 侏羅紀中期—白堊紀晚期 | Geological Age Mid-Jurassic – Late Cretaceous |
| 描述 蛤目、牡蠣科 俗稱：雞冠牡蠣 在蟲的頂端突起，在其球形身上有刺勾。殼管狀，殼表面佈滿深溝槽分割的脊。 生活環境與習性：生活於溫暖淺海，議殼嘴附著於碎殼或珊瑚上。這是來自馬達加斯加Tulear省的Rastellum carinatum的侏羅紀老化石牡蠣。它有寬而彎曲的肋骨，導致它被稱為“義齒蛤”。 兩個殼體之間的之字形連接阻止了粗糙的污垢和碎屑進入殼體並損壞其柔軟的身體。像現代牡蠣一樣，它生活在淺海岸水域，包括潮間帶（高潮和低潮之間的區域），並以從海水中濾出的食物顆粒為食。 附註：兩殼連接的端部隱蔽，可能是為了防備其他肉食動物的攻擊。 | Descriptions It is a knot like protrusion at an extreme end of a tapeworm, it is globular, spiny and has hook on it. This is a Jurassic aged fossil oyster of the species Rastellum carinatum from Tulear Province, Madagascar. It has wide, angled ribs that have led to it being called the ‘denture clam’. The zig-zag join between the two shells stopped coarse dirt and debris entering the shell and damaging its soft body. Like modern oysters it lived in shallow coastal waters including the intertidal zone (the area between high and low tide) and fed on food particles that it filtered out of the sea water. |
| 地點 馬達加斯加 | Location Madagascar |
| 參考 Reference https://www.flickr.com/photos/jsjgeology/17383917212 | |
| 編者 由3A (8) 賴俊凱 於 29/5/2018 編寫 3C (29) 趙梓匡於30/5/2019最後編改 | Editor Created by 3A (8) Lai Chun Hoi on 29/5/2018 Last modified by 3C (29) Chiu Tsz Hong Japaer on 30/5/2019 |
