Discover and read the best of Twitter Threads about #ScienteaficABC
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Finally! Back with another #ScienteaficABC 😁The next in my alphabetical journey through all 128 (currently, anyway) spider families is ANAPIDAE! This family of diminutive spiders contains 58 genera/231 species as of now. (images: Conoculus lyugadinus by Akio Tanikawa, CC) 
They occur worldwide, but mostly S. America, Africa, Asia & Australia/NZ. A few species are found in Europe and North America as well. (Image: Micropholcomma sp. by tjeales on iNat, CC)
Interestingly, Anapidae have either 6 or 8 eyes, with the posterior median pair being either reduced in size or totally absent. They do not exceed around 2mm in body length so, as a family, are very small. (Image: Micropholcomma sp. tjeales on iNat, CC)
Today's #ScienteaficABC spider family is ANAMIDAE! A brand spanking new family, having only been elevated to full family status in this hell year 2020. Formerly, these spiders were a tribe, then a subfamily, of the family Nemesiidae. (Images: iNat Creative Commons)
This family comprises 10 genera/104 species. These are mygalomorph spiders, an infraorder containing tarantulas, trapdoors, funnel webs, curtain webs & others characterised by their downward pointing chelicerae & fangs (& other things). (Chenistonia maculata by matthew_connors)
Native to Australia, 3 genera of this family (Aname, Chenistonia & Namea) are commonly called 'wishbone spiders' owing to the shape of the burrows they create. The silk-lined burrow is Y-shaped with one branch of the Y being longer than the other.
Bonus round! #ScienteaficABC. A small thread for this family AMMOXENIDAE! Why small? A few reasons. Firstly, it's a small family- 4 genera/18 species total, & secondly, they’re a specialised familiy so a broad summary should be pretty quick! (Images: Creative Commons, see end)
Ammoxenidae are commonly known as termite hunters. They are found in Africa & Australia, living on sand dunes, savannahs & bushland in both arid & tropical areas. They actively hunt for termites & when they're not hunting, they dig themselves into the sand. (Img: iNat cecileroux)
Once dug into the sand, they spin a silken retreat which is sticky on the outside so that sand grains stick to it & conceal it. They have adaptations to their chelicerae that enable them to dive face first into the sand and disappear from sight in seconds. (img: iNat peterwebb)
Another #ScienteaficABC. AMAUROBIIDAE! This family comprises 49 genera & ~275 species & can be found mostly around the world save for large swathes of the African, Asian & Australian continents, the Arctic & Antarctica. (images Wikimedia Commons & my own).
Amaurobiid spiders are generally quite rounded & velvety looking, not too vibrant or brightly coloured in most cases (though as you can see here, A. similis does try!), vary in size from 5-30+mm body length, & tend to inhabit cracks, crevices & other sheltered spots. (Pic: mine)
As with other spider families, eye arrangement is helpful (though by no means foolproof) in identifying Amaurobiidae. Here, enjoy another of my terrible diagrams! I shall accompany it with a photo to show you how they look on an actual A. fenestralis. (Image: Wikimedia Commons)
Next up in #ScienteaficABC, AGELENIDAE! This family comprises 87 genera, totalling 1307 species & has an almost cosmopolitan distribution making it a commonly encountered family. The pic shows a few examples of members & some common features. (Images: Wikimedia Commons & my own)
Agelenid spiders vary quite a lot in appearance from genus to genus, but generally can be identified by eye arrangement (see my awful pic), web type/habitat & shape of cephalothorax... though, as always, there are some that do not fall in line with this which makes things fun 😂
Some members of this family are commonly confused with other types of spider. Take this as an example... Agelenopsis sp. (grass spider) vs. Rabidosa rabida (wolf spider), both from Virginia. The most reliable way to tell them apart is their eyes & spinnerets. (Pics: Wikimedia)
Kicking off #ScienteaficABC, taking it from the top with Actinopodidae! This is a family of mygalomorph spiders (an infraorder of heavy bodied spiders with downward facing chelicerae), comprising just 3 genera- Actinopus, Missulena & Plesiolena. (All images: Wikimedia Commons).
Actinopodidae can be found in Australia and Central & South America. They are considered medically significant, which means their venom is potentially dangerous. Overall, they are heavy set, impressive looking spiders, usually with a stocky legs, large chelicerae & fangs.
Perhaps most recognisable of this family are Missulena spp. The mouse spiders! Found mostly in Australia, 1 of the 18 species is found in Chile. This is a male M. occatoria native to S. Australia. Females do not exhibit the bright red that the males do & tend to be heavier set.
