An Ankylosaur OF A DIFFERENT SORT

Ankylosaurs were weird and now a new species adds a new degree of weirdness. Welcome to Stegouros elengassen!

As plant eaters in a Mesozoic world dominated by towering meat-eaters, ankylosaurs needed to be well armored. Stegouros elengassen was a mere six-and-a-half feet long, but it sported a flat, frond-shaped tail resembling a chainsaw. Says paleontologist James Kirkland, a whack from this tail would be like getting “whacked in the shins by a battle-ax.” Ouch!

University of Texas paleontologists discovered Stegouros in the subantarctic region of Río Las Chinas at the tip of Chile during the last five days of their 2018 field season. Its excavation resulted in a broken rib, hypothermia and a sprained ankle among those working to free the bones in frigid conditions. At least no one got whacked in the shins by a battle-ax!

Finally freed, cleaned and examined, the resulting 75-million-year-old critter has now been described in the journal Nature by a team of paleontologists including Alexander Vargas (University of Chile),

Marcelo Leppe (Chilean Antarctic Institute) and others. The skeleton was nearly 80 percent complete. Said Vargas, “Books on prehistoric animals for kids need to update and put this weird tail in there….It just looks crazy.”