 <unk> was named by German <unk> Karl Alfred von <unk> in his second edition of <unk> der <unk> , published in 1888 . <unk> remains were known since the early part of the 19th century , however . The earliest described <unk> was <unk> , named by Georg Friedrich <unk> in 1828 . <unk> named <unk> from a single tooth , and considered it a reptile . <unk> means " breast tooth lizard " after the <unk> @-@ like shape of the tip of the tooth . 
