Google have recently announced that they are experimenting with longer headlines in some of the top placement ads. These are the ads that appear above the organic search results.
For now, it looks like they are pulling the description line 1 up to the headline. When this occurs, they place a hyphen to separate the two. There’s no need to rush and update your headlines so that they each contain proper punctuation.
On the subject of punctuation, however, you will need to have proper punctuation at the end of the first description line in order to have it inserted into the headline.
Google will hopefully allow more control over this by allowing for alternate extended headlines when creating text ads