It was in the year 1998 that Bjarni Kr. Kristjánsson biologist found a type of amphipoda in Thingvallavatn. It has now got the scientific name Crymostigius thingvallensis. The amphipoda has now also been found at Herðubreiðarlindir in NE Iceland. Similar amphipoda can be found in Ireland and South England in the east, and at the border of Canada and the US in the west. Therefore, it is reasoned that Crymostigius thingvallensis has evolved independently at the location for millions of years, from the time when the two continents of Europe and America were connected.

The area is said to separate the two tectonic plates of N-America and Eurasia. The finding of the Crymostigius thingvallensis is assuring. Today, geologists tend to emphasise the tectonic drift factor, pointing that the main division line is actually south of Thingvellir Rift Valley, so the area is the division line between Hreppar miniplate and the N-American Tectonic Plate. With our amphipoda, it should still be possible to claim that the area is a long term border area due to tectonic drift. That means that favorable conditions are prevalent for millions of years due to the pulling effect of pemanent mantle currents underneath. The rocks seen in the picture are only 9.000 years old, as the rifts constantly renew themselves, and new lava fields add nutrition to this very special lake.
.https://www.thingvellir.is/fraedsla/nattura/lifriki-vatnsins/