鹦鹉螺化石，这些螺旋状的贝壳，经常分布在二叠纪的化石群中。
Ammonoids, with their tightly coiled, spiral shells, are also widespread in the Permian fossil record.
菊石是鹦鹉螺的近亲，这种外壳呈螺旋状的海生生物在6500万年前与恐龙一起灭绝了。
Related to the pearly nautilus, these spiral-shelled Marine creatures went extinct along with the dinosaurs around 65 million years ago.
蜘蛛螺(Lambis chiragra)就是其中一种海底生物，它属于腹足软体动物，壳上有6个指状突起。
The spider conch (Lambis chiragra), a gastropod mollusk with six fingerlike projections sticking out of its shell, is one of these seabed dwellers.
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