n.奥陶纪，奥陶系
adj.【地】奥陶纪[系]的

The Ordovician Period, lasting from about 485 to 443 million years ago, was a time of significant marine life diversification.
奥陶纪，大约发生在距今4.85亿至4.43亿年前，是一个海洋生物多样性显著增加的时代。
During the Ordovician, trilobites and brachiopods were abundant in the oceans, forming an essential part of the marine ecosystem.
在奥陶纪时期，三叶虫和腕足动物在海洋中极为丰富，构成了海洋生态系统的重要组成部分。
The Ordovician-Silurian extinction event, around 443 million years ago, led to the disappearance of nearly 60% of all marine species then living.
大约在4.43亿年前的奥陶纪-志留纪灭绝事件导致了当时几乎60%的海洋物种消失。
Fossilized corals found in Ordovician rock formations indicate that shallow tropical seas covered large parts of the Earth during this era.
从奥陶纪岩层中发现的珊瑚化石表明，在这个时代，浅海热带海域覆盖了地球上的大片区域。
In the early Ordovician, continental drift caused the supercontinent Gondwana to move towards the South Pole, leading to major climate changes.
在早奥陶世，大陆漂移使得冈瓦纳超大陆向南极移动，引发了重大的气候变化。
The first fish with jaws appeared in the late Ordovician, marking a major evolutionary step for vertebrates.
到晚奥陶世时，出现了第一批有颌鱼类，标志着脊椎动物的一次重大进化。
Deposits from the Ordovician period have been extensively studied by geologists, providing valuable insights into the Earth's geological history.
地质学家们对奥陶纪时期的沉积物进行了广泛的研究，为了解地球地质历史提供了宝贵的信息。
Unique Ordovician fossils found in the Canadian Shield provide evidence of ancient life forms and their environment.
在加拿大盾区发现的独特奥陶纪化石为研究古代生命形式及其环境提供了证据。
The Ordovician System is divided into three series: the Lower, Middle, and Upper Ordovician, based on stratigraphic criteria.
根据地层层序标准，奥陶纪系统被划分为下奥陶统、中奥陶统和上奥陶统三个系列。
Some scientists believe that the Late Ordovician ice age contributed to the mass extinction at the end of the period.
一些科学家认为，晚奥陶世的冰河时代可能促成了该时期的末期大灭绝。