Ray Orbweavers - Family: Theridiosomatidae
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Also known as Ray Spiders, the Theridiosomatidae are a family of 141 species in 20 genera although only two species from two genera may be found in the Northern Rivers. They were first described by The French arachnologist Eugene Simon in his book The Arachnids of France, Vol. 5, Part 1. in 1881. Many species of the Theridiosomatidae are known from type specimens only which means thay are not often seen and so little is known about their habits and behaviours.
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Most spiders in this family are quite small, their bodylength not often exceeding 2 mm and many have rather short legs giving them a somewhat stout appearance. They are occassionally encountered near water such as small creeks and in damp areas nearby. Their small cone-shaped webs often with a hub loop therein, are a give-away of their location. Some females of Ray Spiders deposit their eggs into small ovoid eggsacs that are suspended from thick threads.
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Ray Spiders appear to have been around for considerable time; Baltic amber from the Eocene era, 56 - 34 Mya, found in the Russia, Poland and Germany has been shown to contain fossils of a number of Theridiosomatid spiders. At least four extinct genera of Ray Spiders have been identified from this source material although the exact age of the amber in which they were discovered remains disputed.
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Baalzebub brauni (likely occurrence)
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Theridiosoma circuloargentatum (possible occurrence)
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Taxonomy:
Phylum: Arthropoda (Arthropods)
> Subphylum: Chelicerata (Chelicerates)
> Class: Arachnida (Arachnids)
> Order: Aranea (Spiders)
> Suborder: Araneomorphae (Typical Spiders)
> Infraorder: Entelegynea (Entelegyne Spiders)
> Superfamily: Araneoidea (Araneoid Spiders)
> Family: Theridiosomatidae (Ray Orbweavers)
> Genus: Baalzebub
> Species: B. brauni *
> Genus: Theridiosoma (Ray Spiders)
> Species: T. circuloargentatum ^
* = likely
^ = possibly
References and links:
> Coddington, J.A., (1986). 'The genera of the spider family Theridiosomatidae.' Smithsonian Contributions to Zoology 422: 1-96.
> Simon, E., (1881). Les Arachnides de France. Tome cinquieme, premiere partie. Roret, Paris, pp. 1-180.
https://en.wikipedia.org/wiki/Baltic_amber
https://en.wikipedia.org/wiki/Ray_spider
> Coddington, J.A., (1986). 'The genera of the spider family Theridiosomatidae.' Smithsonian Contributions to Zoology 422: 1-96.
> Simon, E., (1881). Les Arachnides de France. Tome cinquieme, premiere partie. Roret, Paris, pp. 1-180.
https://en.wikipedia.org/wiki/Baltic_amber
https://en.wikipedia.org/wiki/Ray_spider
Photographic contributions: