Tarantula with enormous horn astonishes scientists

If tarantulas weren't scary enough already, now there's a species with a massive horn to worry about.

Scientists have discovered a new species of the venomous arachnids, which bear a bizarre protrusion on their backs.

It's so odd, they've named the new spider Ceratogyrus attonitifer - the latter word meaning 'the bearer of astonishment'.

"No other spider in the world possesses a similar... protuberance," the scientists, working as part of the National Geographic Okavango Wilderness Project, wrote.

Ceratogyrus attonitifer belongs to a family of spiders known as 'horned baboons', but its horn is not only incredibly large, it's also kind of soft and hairy.

"The function of the curious structure remains unknown."

Ceratogyrus attonitifer.
Ceratogyrus attonitifer. Photo credit: Ian Enelbrecht/supplied

Before you run to get the Raid however, here's the good news: Ceratogyrus attonitifer venom isn't particularly strong, and so far it's only been found deep in the largely unexplored forests of the southern African country of Angola.

Presenting their findings in journal African Invertebrates, the scientists said the discovery of Ceratogyrus attonitifer shows how little they know about wildlife in the region.

"The general paucity of biodiversity data for Angola is clearly illustrated by this example... highlighting the importance of collecting specimens in biodiversity frontiers," the scientists wrote.

Ceratogyrus attonitifer.
Ceratogyrus attonitifer. Photo credit: Ian Enelbrecht/supplied

But as is often the case, indigenous locals already knew about them - calling them 'chandachuly' - and claiming bites were occasionally fatal due to poor medical access in the region.

The find comes just after a "rain" of spiders was caught on camera in Brazil

Newshub.