Details of a new tarantula previously unknown to science have been revealed by researchers working in Angola. The spider has a very peculiar feature, unlike any other related species we have encountered so far. It has been named Ceratogyrus attonitifer (attonifer is derived from Latin as "the bearer of astonishment") for good reason. This new species has a horn-like feature that sticks out from the back of its head and stretches across almost its entire body.
“The new species of Ceratogyrus described here is remarkable. No other spider in the world possesses a similar foveal protuberance,” the authors write in their study, published in the journal African Invertebrates. They also have no idea what it is for.
C. attonitifer is only a handful of centimeters in length and mostly preys on insects. It belongs to a group called horned baboon spiders, some of which (though not all) have horns. These relatives, however, are much smaller and their "horns" harder, like insects' exoskeletons. But C. attonitifer's horn remains soft, and is longer than other species', making this creature unique among this group.
Although only recently described, the indigenous people of the region have long known about it, calling it "chandachuly", and their experience with these arachnids has provided fundamental insights into their biology and lifestyle.
Between 2015 and 2016, the researchers collected several female specimens from the miombo forests of central Angola. They discovered that the females tended to enlarge already existing burrows rather than digging their own new ones. They also discovered that they are venomous but they are not believed to be dangerous to humans. There have been fatalities reported about bites from this spider but it is believed that infections and poor medical access have been the cause of death, not the venom.
The discovery is part of the National Geographic Okavango Wilderness Project, which hopes to better understand the biodiversity along the Okavango river that flows through Angola, along the Namibian border, and into Botswana.
This work is important because it shows that the range of these horned baboon spiders is very vast, stretching almost 600 kilometers (373 miles). The authors suggest that further work should focus on adult males, as well as better understanding the relationship between C. attonitifer and other members of its genus, and what makes it so different.