Note: The article shares a common misconception about beetle anatomy, that the thorax is short and only has one pair of legs. Like all other insects, beetles thoraxes have three pairs of legs. It's just that their abdomen is shorter than it appears.
See this video from Clint's Reptiles for the explanation: https://youtu.be/-aV78eNbdTU?si=DCe3ZUx8C6IKlXJe&t=978