It's a rough universe out there and any self-respecting planet needs a a giant robot/monster to defend it against robeasts, kaiju and mechs. In this monstrous arms race, you'll find few combatants more fearsome that Gurion, that blade-headed slicing machine that protects the destitute counter-Earth planet of Terra.
The monster famously took Kaiju superstar Gamera to the limit back in 1969 -- and this after slicing Space Gyaos into cosmic sushi. His ability to launch bio-shurikens certainly sets him apart from most natural-world organisms, but Guiron's very name stems from the titanic guillotine-like blade that defines his head.
Gurion is clearly the genetically-engineered product of brain-sucking aliens, but he isn't the only creature to ever head-bang its blade face into the flesh of an adversary. Let's leave the unnatural world of monsters and venture into the very-real world of prehistoric terror birds...
Hatchet Face Terror Bird
Travel back in time about 50 million years to the early Eocene epoch and you'll find the only time in history when birds ruled the world. They permeated most of the key positions in the food chain and large, flights "terror birds" stalked the land. At least 18 species of these avian nightmares thrived in South America (with some reaching heights of 7 feet), up until the continent's collision with North America 2-3 million years ago.
We don't know much about their behavior, but according to a 2010 multinational study published in PLOS One, terror bird Andalgalornis steulleti probably used its massive beak to land "well-targeted, hatchet-like jabs" to its enemies.
With the use of a CT scanner, scientists discovered that while most bird skulls feature mobile joints, this one boasted rigid beams -- particularly in the fore-aft portion. Further analysis revealed that while the bird's bite strength and side-to-side thrashing ability was weak, it's powerful neck muscles allowed for it to compensate. It simply drove its head into enemies with vertical axe strokes. Furthermore, they posited that A. steulleti likely employed a "repeated attack-and-retreat strategy" to fell its adversaries.
Sadly, fossil evidence has yet to suggest how it might have battled a like-sized turtle.
Monster of the Week is a - you guessed it - regular look at the denizens is of our monster-haunted world. Sometimes we'll focus on the cultural aspects, but mostly we'll look at the possible science behind a creature of myth, movie or legend. Be sure to explore the Monster Gallery as well as the Monster Science video series.