Collinsium ciliosum, a Collins’ monster-type lobopodian from the early Cambrian Xiaoshiba biota of China. (Jie Yang)

Roughly 500 million years ago, a worm covered in up to 72 spikes roamed what is now China.

That kind of body armor was rare until then; the Collinsium ciliosum, or Hairy Collins' Monster, was among the first soft-bodied animals on Earth to develop skeletonized body parts for protection, according to researchers who just discovered the species. They described the worm as "superarmored" in a study published Monday in the journal Proceedings of the National Academy of Sciences.


Reconstruction of Collinsium ciliosum. (Javier Ortega-Hernández)

A well-preserved fossil of the Hairy Collins' Monster was found in a Southern Chinese deposit site. The worms are thought to have been more than three inches long and eyeless with nine pairs of rear legs that ended with claws. Researchers believe the monster worm, unable to really walk around a muddy ocean floor with those claws, likely hooked itself to hard surfaces and used its six pairs of front legs, which had bristles, to filter food.

So why the spikes all over? These guys could have made for some easy prey, given that they pretty much stayed put as they ate and had squishy bodies. The sharp spikes protected them from being gobbled up, researchers reasoned.

[This freaky ancient worm shows what spider and insect ancestors might have looked like]

The Hairy Collins' Monster -- named after paleontologist Desmond Collins, who illustrated a similar Canadian fossil three decades ago -- lived during the Cambrian period, an explosive time of evolution within the Paleozoic Era. The worm is considered an early ancestor of onychophroans, or velvet worms, which live in tropical forests, and also resembles another Cambrian fossil, the Hallucigenia.

"Both creatures are lobopodians, or legged worms, but the Collins' Monster sort of looks like Hallucigenia on steroids," study co-author Javier Ortega-Hernández of the University of Cambridge said in a statement. "It had much heavier armor protecting its body, with up to five pointy spines per pair of legs, as opposed to Hallucigenia's two. Unlike Hallucigenia, the limbs at the front of Collins' Monster's body were also covered with fine brushes or bristles that were used for a specialized type of feeding from the water column."

[Ancient filter-feeding giants hint at the evolution of today’s insects]

The creature -- and similar superarmored lobopodians -- went extinct during the early Palezoic Era. Ortega-Hernández described the Hairy Collins' Monster as one of the many "evolutionary experiments" during the Cambrian period, "one which ultimately failed as they have no living direct ancestors -- but it's amazing to see how specialized many animals were hundreds of millions of years ago."


Collinsium ciliosum, a Collins’ monster-type lobopodian from the early Cambrian Xiaoshiba biota of China. (Jie Yang)

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