According to the old English legend, Excalibur is a magical sword wielded by the legendary King Arthur — purveyor of round tables and protector of Britain in the fifth and sixth centuries. Today, the legend of that enchanted blade lives on… in the name of a prehistoric worm that you could crush between two fingers.
Meet Lepidocoleus caliburnus. Measuring just a fraction of an inch long), this ancient, sea-dwelling creepy-crawler may not reach the stature of its Arthurian namesake — but, as a new study in the journal Papers in Palaeontology points out, it did at least look the part of a heavily-armored knight, covered in overlapping plates of calcite crystals that ran along the entire length of the creature's body.
