Haplogyne  Spiders - Infraorder:   Haplogynae
"Spiders are born to spin; they do not need to be taught. A spider's web is its home. Some spiders use a web to catch their prey, while others prefer to hunt."    Kay de Silva  -  Australian author of the 'Our Amazing World Series' of childrens' books.
      The Haplogyne Spiders have long since been the second group in the Suborder: Araneomorphae or Typical Spiders.  Recent research however, has cast doubt over the monophyly of this infraorder.  As a whole, the Haplogynae are different from the Entelegynae in that the female genitalia of Haplogyne Spiders have not been hardened by conversion into sclerotin.  From that point of view the division into the two infraorders seems justified.  However, among Haplogyne Spiders there are other substantial morphological differences that makes justification for their placement in the same infraorder rather diffiicult and a few different arrangements have been put forward of late including one in which the Araneomorphae is divided into three sections and the Haplogynae spread out amongst all three. So, while the jury is still out, the traditional division of the Araneomorphae into Entelegynes and Haplogynes will be adhered to.
      The oldest Haplogyne fossil found to date is that of a species in the Family: Plectreuridae and is dated at around 165 My old.  It was found in the province of Inner Mongolia in China.  The fossil appears to be quite similar to the extant species in the family which is said to "demonstrate evolutionary conservatism".  This concept a.k.a. phylogenetic niche conservation, refers to the idea that descendants tend to retain their ancestral traits.  This then, implies an explanation for why closely related species share so much of their ancestral DNA; speciation usually involves only small changes in DNA, not complete 'rebuilds'. 
As per the current taxonomic arrangement, the Haplogynae are divided in to twenty-one families of which eightteen are spread over seven superfamilies leaving three unplaced. Six of these superfamilies are represented in Australia but only two of these six could be considered common. 
      As stated before there are substantial morphological differences among spiders in Haplogynae.   With regards to size, they range from small to large and from robust to slender.  Many have eight eyes but others may have six, four or even just two.  They come with or without a cribellum which, of course, has implications for the kind of silk they produce.  Some build webs, others do not.  Some have fused chelicerae, one of the more unusual features.  Despite making up for less than 14 % of all total spider species, the Haplogynae are by no means less diverse or interesting.
References  and  links:
​
>      Kulkarni, S.,  Wood, H.M.  and  Hormiga, G.,  (2023).   'Advances in the reconstruction of the spider tree of life: A roadmap for spider systematics and comparative studies.' Cladistics, 39: 479-532.   https://doi.org/10.1111/cla.12557
>      Selden, P.  and  Huang, D., (2010).   'The oldest haplogyne spider (Araneae: Plectreuridae), from the Middle Jurassic of China.'  Die Naturwissenschaften. 97. 449-59.
DOI: 10.1007/s00114-010-0649-z. ​
>      Wheeler, W.C., Coddington, J.A.  et al, (2017).   'The spider tree of life: phylogeny of Araneae based on target-gene analyses from an extensive taxon sampling.'  Cladistics, 33 (6): 574–616.   doi:10.1111/cla.12182.

      https://en.wikipedia.org/wiki/Sclerotin
      https://en.wikipedia.org/wiki/Phylogenetic_niche_conservatism​
      https://www.mindat.org/taxon-P376963.html

Header photo:

Note:  Copyright rules vary.  Please contact the editor prior to using any of the images published on this site.