Question

Describe the evolutionary history of snails (Molluscs). In which eon, era and period did the first snails evolve?

Answer 1

According to the records of fossils, the first gastropods exist in the sea and probably emerge in the Cambrian period in the Mesozoic era. Beginning this, the mollusks of the genera Chippewaella and Strepsodiscus developed to be converted into the most ancient snails.

The Helcionellids first appeared over 540 millions of year ago in the Early Cambrian rocks from China and Siberia, are considered to be early mollusks with somewhat snail-like shells. The shelled mollusks, therefore, predate the first trilobites.

Land snails were possibly originated from the freshwater species rather than the saltwater species because less adaptation is desired to compensate for osmotic requirements. The Present-day species of snail can live in different environments, from the deep sea to the desert.

The ancestors of the Snails' are one of the most primitive identified categories of animals in the world. There is fossil proof of primitive gastropods dating back to the late Cambrian period, this indicates that they lived almost 500 millions of years ago.