ichthyosaur

1. The ichthyosaur remains are found in black, bituminous marine shales deposited about 190 million years ago.
   人们在黑色的、含沥青的海洋页岩中发现了约19000年前沉积下来的鱼龙化石。
2. The quality of preservation is outstanding, but what is even more impressive is the number of ichthyosaur fossils containing preserved embryos.
   它们的保存质量非常的好，但更令人称奇的是保存下来的育有胚胎的鱼龙化石数目。
3. Given these factors, some areas have become a treasury of well-preserved ichthyosaur fossils.
   当这些因素存在时，某些地区就会变成一个充满保存完好的鱼龙化石的宝库。

noun

1. any of several marine reptiles of the Mesozoic having a body like a porpoise with dorsal and tail fins and paddle-shaped limbs