| 名稱 鯊魚牙化石 | Name Shark Tooth Fossil |
| 地質年代 / | Geological Age / |
| 描述 鯊魚最早於三億八千萬年前(泥盆紀)開始出現，牠們屬於軟骨魚類，身體沒有魚鰾，擁有鰭部和流線型的身體，游泳速度極快， 是天生的掠食者，鯊魚數億年來於海洋中的地位一直居處於最頂層，其外表至今並沒有大的改變。由於軟骨魚類死後的骨骼分解要比硬骨魚類容易得多，所以完整的鯊魚化石是非 常罕見，而鯊魚的牙齒因為經常會自然脫落或在進食時掉落 (但牙齒仍是會不斷更新)，加上牙齒比較堅硬，所以於地層中經常可以找到各種鯊魚的牙齒化石。可以分析這些化石的鯊魚進化和生物學信息; 它們通常是鯊魚化石的唯一部分。 化石牙齒構成了板鰓亞綱的大部分化石記錄，延續了數億年。 鯊魚牙齒也可用於研究牙齒結構，鯊魚遷移模式和識別鯊魚物種。 | Description In some formations, shark’s teeth are a common fossil. These fossils can be analyzed for information on shark evolution and biology; they are often the only part of the shark to be fossilized. Fossil teeth comprise much of the fossil record of the Elasmobranchii, extending back to hundreds of millions of years. Shark teeth are also useful in conducting research about the structure of teeth, shark migration patterns, and identifying shark species. The most ancient types of sharks date back to 450 million years ago, during the Late Ordovician period, and are mostly known by their fossilised teeth. However, the most commonly found fossil shark teeth are from the Cenozoic era (the last 66 million years). |
| 地點 / | Location / |
| 參考 Reference http://www.fossilshk.com/shark.html https://en.m.wikipedia.org/wiki/Shark_tooth | |
| 編者 由 3E (13) 關風靜 於4/6/2018編寫 由3B (21) 仇彥博 和 3B (29) 蔡培熙 於30/5/2019最後編改 | Editor Created by 3E (13) Kwan Fung Ching on 4/6/2018 Last modified by 3B (21) Shou Ethan and 3B (29) Tsoi Pui Hei Samson as on 30/5/2019 |
