Editing Orb-weaver spider (section)

== Taxonomy ==
[[File:Argiopespain.jpg|thumbnail|right|''[[Argiope lobata]]'' in southern [[Spain]]]]

The oldest known true orb-weaver is ''[[Mesozygiella dunlopi]]'', from the [[Lower Cretaceous]]. Several fossils provide direct evidence that the three major orb-weaving families, namely the Araneidae, Tetragnathidae, and Uloboridae, had evolved by this time, about 140 Mya.<ref name=PenaGrimDelc06/> They probably originated during the Jurassic ({{Ma|200|140}}). Based on new molecular evidence in silk genes, all three families are likely to have a common origin.<ref name=GarbDemaVoHaya06/><ref name=PennOrtu06/><ref name=Blac09/>

The two superfamilies, Deinopoidea and Araneoidea, have similar behavioral sequences and spinning apparatuses to produce architecturally similar webs. The latter weave true viscid silk with an aqueous glue property, and the former use dry fibrils and sticky silk.<ref name=GarbDemaVoHaya06/><ref name=Shea86/> The Deinopoidea (including the Uloboridae), have a [[cribellum]] – a flat, complex spinning plate from which the cribellate silk is released.<ref name=Codd86/>

They also have a [[calamistrum]] – an apparatus of bristles used to comb the cribellate silk from the cribellum. The Araneoidea, or the "ecribellate" spiders, do not have these two structures. The two groups of orb-weaving spiders are morphologically very distinct, yet much similarity exists between their web forms and web construction behaviors. The cribellates retained the ancestral character, yet the cribellum was lost in the escribellates. The lack of a functional cribellum in araneoids is most likely [[synapomorphic]].<ref name=Codd86/>

If the orb-weaver spiders are a [[monophyletic group]], the fact that only some species in the group lost a feature adds to the controversy. The cribellates are split off as a separate taxon that retained the primitive feature, which makes the lineage [[paraphyletic]] and not synonymous with any real evolutionary lineage. The morphological and behavioral evidence surrounding orb webs led to the disagreement over a single or a dual origin.<ref name=Codd86/> While early molecular analysis provided more support for a [[monophyletic]] origin,<ref name=GarbDemaVoHaya06/><ref name=PennOrtu06/><ref name=Blac09/> other evidence indicates that orb-weavers evolved earlier phylogenetically than previously thought, and were extinct at least three times during the [[Cretaceous]].<ref name=Fernández2018>{{cite journal |last1=Fernández |first1=R |last2=Kallal |first2=R.J. |last3=Dimitrov |first3=D |journal= Current Biology|title=Phylogenomics, diversification dynamics, and comparative transcriptomics across the spider tree of life.| date=2018 |volume=28 |issue=9 |pages=1489–1497.e5 |pmid=29706520|doi=10.1016/j.cub.2018.03.064 |doi-access=free |bibcode=2018CBio...28E1489F }}</ref><ref name=Garrison2016>{{cite journal |last1=Garrison |first1=N |last2=Rodriguez |first2=L. J. |last3=Agnarsson |first3=I |last4=Coddington |first4=J.A. |last5=Griswold |first5=Charles E. |last6=Hamilton |first6=C.A |last7=Hedin |first7=M. |title=Spider phylogenomics: untangling the spider tree of life |journal=PeerJ |date=2016 |volume=4 |page=e1719|pmid=26925338|pmc=4768681|doi=10.7717/peerj.1719 |doi-access=free }}</ref><ref name="Dimitrov-Hormiga-2020"/>