As one of the epicenters of modern science, the United Kingdom is one of the most studied regions on this planet. That's why it's surprising when scientists discover a new species within the island nations’ shores, and even more so when it turns out that new species is a fairly large vertebrate to boot.
In Science Advances, researchers describe a new species of snake in the UK, now known as the barred grass snake (Natrix helvetica). Previously, it was thought to be a slightly different patterned subspecies of the common grass snake (Natrix natrix). Living in the UK, France, Switzerland, Italy, and Western Germany, N helvetica is not only different in color, but also genetically divergent enough to be considered a distinct species.
Despite being known as a grass snake, the reptiles actually like to spend much of their time hunting in ponds, rivers, and streams, where amphibians are thought to make up the majority of their diet.

The new species differs from the common variety, as while both may reach up to a meter (3 fteet) in length, the common species is olive green and has a yellow collar, whereas the barred type is more grey in coloration, lacks yellow around its neck, and has black markings along its whole length.
Both species are found in the lowlands of southern England, but it was only through testing the genetics of 1,600 specimens held in museum collections that they were able to conclusively say the two varieties are different enough to be considered separate species.
The researchers then followed this up by looking at two regions on the continent where both genetic lineages come into contact and found that there are significant barriers that prevent the snakes from interbreeding.
The UK is not particularly well known for its diverse array of reptiles, with the country experiencing cold winters and damp summers not particularly well loved by cold-blooded creatures. This means that the newly named barred grass snake will now become only the seventh species of British reptile, joining the common lizard, sand lizard, slow worm (actually a lizard), the common grass snake, smooth snake, and the adder, the UK’s only venomous snake.