Ceratogyrus marshalli

Ceratogyrus marshalli

Ceratogyrus marshalli Pocock, 1897, also known as “Straight horned baboon” or “Great horned baboon”, is a very beautiful bird spider due to its remarkable horn on the centre of her carapace from Zimbabwe and Mozambique. African bird spiders are commonly given the title of baboon spider, which title theoretically only belongs to the subfamily of the Harpactirinae. Therefore Ceratogyrus can be considered a real baboon spider. Ceratogyrus darlingi was the first species of the genus to be discribed in 1897, together with the male Ceratogyrus marshalli. De Wet & Dippenaar-Schoeman were able to describe Ceratogyrus cornuatus in 1991, which turned out later to be the female Ceratogyrus marshalli. The Ceratogyrus-genus is well known for their beautiful horns, but in fact only half of the genus is blessed with it. Except for Ceratogyrus paulseni, however, all species do have a subabdominal band in the booklung region.


Scientific name: Ceratogyrus marshalli.

Subfamily: Harpactirinae.

Common names: Straight horned baboon. Great horned baboon.

Previous namesCeratogyrus dolichocephalus Hewitt, 1919, Ceratogyrus cornuatus De Wet & Dippenaar-Schoeman, 1991.

World spider catalog

Type: Burrowing bird spider.

Category: Old world tarantula.

Urticating setae: No.

Venom: Probably strong. Depending the location of the bite and the amount of venom released, this might be a painful experience. However, no valuable scientific research has been done yet.

OriginAfricaZimbabwe (Harare), Mozambique.

Body length: ≤ 6cm.

Span width: ≤ 15-16.

Life expectancy: Females become up to 8-10 years old. Males are given a shorter lifetime of 3-4 years.

Behavior: Ceratogyrus marshalli is a very defensive and unpredictable bird spider. The spider will try to flee at first. Persistent provocation will probably result in stridulation and a bite. She’ll make herself a J-shaped burrow deep underground. At broad daylight she’ll stay deep inside her burrow, waiting for an unsuspecting prey at the entrance of her burrow at night. Ceratogyrus marshalli can be considered a pet hole, so know what to expect when buying. 

Growth rate: Fast.

Accessibility (1/beginner, 10/expert): 10.


>>> First aid

Ceratogyrus marshalli is originally inhabited in Harare, Zimbabwe. Due to the fact this city is located about 1500m above sea level, maximum temperatures are fairly constant. Winter enlasts 7 months and is rather cool and dry. The following 5 months, summer, it is rather warm and humid.

Environmental conditions

Temperature: 25-28°C (day), 20-24°C (night).

Humidity: 70-80% (summer), 50-60% (winter).


Adult: LxWxH: 30x30x30. Min. 2x span width in height, 3-4x span width in surface.

Smaller than adult: Min. 2,5x span width in height, 3-4x span width in surface.


Adult: Min. 1,5x span width.

Smaller than adult: Min. 2x span width.

* Provide both moist and dry substrate for younger animals.

* During rainy season (5 months) the spider lives in wet area. Note that cages with high humidity levels are very sensitive for mites and other parasites. Please take your precautions.


Wet season: January, February, March, November, December.

Dry season: April, May, June, July, August, September, October.

Warmest months: October, November.

Coldest months: June, July.

For more information about the local climate: Click here.

* You might like to consider an adjustment of these data with your local climate. Do not exceed minima or maxima and, if necessary, organize the year making your bird spider experience different seasons. This is very important form the moment you’d like to start breeding.

Differences between the horns of the Ceratogyrus-genus

Until today it is still unknown why these horns could have a positive impact on the lives of the tarantulas. Anatomically, the horn is located on top of the fovea. Underneath the fovea, inside the tarantula, the dorsal dilator muscle is attached to the apodeme. Different to all other bird spider the apodeme of the horned Ceratogyrus-species is ringshaped. The increased surface for the attachment of the dilator muscles, inside the horn, could aid in drawing in liquified food into the sucking stomach. On the other hand the increased surface could serve as storage area to survive periods of extreme drought and lack of food (Rick C. West/1986).

Ceratogyrus brachycephalus

Conical, pointless, lower, facing forward.

Ceratogyrus darlingi

Conical, pointless, higher, facing backward.

Ceratogyrus dolichocephalus

Conical, sharper, lower, facing backward.

Ceratogyrus marshalli

Conical, sharper, high, dark, vertical.

Male: Similar to protuberance of Ceratogyrus sanderi, but wider than long.

Ceratogyrus sanderi

Protuberance, dark, longer than wide.

An unknown species from South Africa was discovered. This species shows a conical horn facing backwards, so big that it extends the abdomen (click here for a picture).


Pairings with the Ceratogyrus-genus don’t always run smoothly. Due to the fact both spiders are very timid, it might take a while before you’ll notice some action. In some cases the male has been seen running away before any copulation happened. Cannibalism occurs from time to time, but is not the rule. In order to be successfull breeding with the Ceratogyrus-genus it is very important to provide enough substrate. Breeding projects.

• Only start breeding 4-6 weeks (or later) after the spider molted. If the female molts between pairing and cocoon, the eggs will remain unfertilized.

• Make sure the female is well-fed (not obese) before you introduce the male.

• Introduce both male and female to each other by placing both terraria next to each other a few days before mating. It is possible you notice interactions.

• Foresee an escaping route for the male.

• Plan mating by a humidity of 50-60%, keeping temperatures fairly constant around 25°C.

• Spray the enclosure 1x/week on the glass (not the web) in the following weeks. Don’t do anything special.

• The female will start making the cocoon 1-2 months after mating. Some breeders cover the terrarium with a towel for 1 month. Deprive the cocoon, when desired, 4 weeks after you’ve seen her making it. Store the eggs at a humidity of 70% and a temperature of 26-29°C. Expect 120-180 spiderlings to come out. Plenty of breeders leave the little ones with mommy until nymph II.

• From the moment nymphs upgraded to spiderling, they will start to attack each other within a few hours. Make sure you seperate them before this happens.


• Bird spiders from the subfamily of the Harpactirinae are given the name “baboonspiders” because their legs resemble baboon fingers?

Ceratogyrus hillyardi, – meridionalis, – paulseni and – pillansi are not horned?

• The horn of Ceratogyrus marshalli is the only vertical one?

• There are 2, almost transparant, lines on the horn?

• Horns are only visible as protuberances from the 4th molt? The exception, however, makes the rule. The horn of Ceratogyrus brachycephalus starts showing up from 2nd molt.

• Read more about Ceratogyrus-genus (and other African bird spiders): Click here.


• Pharmacological characterization of venoms from three theraphosid spiders: Poecilotheria regalis, Ceratogyrus darlingi and Brachypelma epicureanum.

A new species of theraphosid spider from Southern Africa (Araneae, Theraphosidae, Harpactirinae) with distributional notes on other harpactirines.


• Text: Dennis Van Vlierberghe (facebookgroup and –page)

• Photography: Julian Kamzol (website, flickr)