Editing Notostraca (section)

{{Short description|Order of small freshwater animals}}
{{Automatic taxobox
| name = Notostraca
| image = Triops australiensis.JPG
| image_caption = ''[[Triops australiensis]]''
| image2 = LepidurusApus.jpg
| image2_caption = ''[[Lepidurus apus]]''
| fossil_range = {{fossil range|Famennian|Recent}}
| taxon = Notostraca
| authority = [[Georg Ossian Sars|G. O. Sars]], 1867
| subdivision_ranks = Genera
| subdivision = *''[[Lepidurus]]'' <small>Leach, 1819</small>
*''[[Triops]]'' <small>Schrank, 1803</small>
*Fossil genera and species, see text
}}
The order '''Notostraca''', containing the single family '''Triopsidae''', is a group of [[crustacean]]s known as '''tadpole shrimp'''<ref name="Light"/> or '''shield shrimp'''.<ref name="Lowry">{{cite web |url=http://crustacea.net/crustace/www/notostra.htm |author=J. K. Lowry |work=Crustacea, the Higher Taxa: Description, Identification, and Information Retrieval |date=October 2, 1999 |title=Notostraca (Branchiopoda) |access-date=February 7, 2011 |archive-url=https://web.archive.org/web/20110723062941/http://crustacea.net/crustace/www/notostra.htm |archive-date=July 23, 2011 |url-status=dead }}</ref> The two genera, ''[[Triops]]'' and ''[[Lepidurus]]'', are considered [[living fossil]]s, with similar forms having existed since the end of the [[Devonian]], around 360 million years ago. They have a broad, flat [[carapace]], which conceals the head and bears a single pair of compound eyes. The abdomen is long, appears to be segmented and bears numerous pairs of flattened legs. The [[telson]] is flanked by a pair of long, thin caudal rami. [[Phenotypic plasticity]] within taxa makes species-level identification difficult, and is further compounded by variation in the mode of reproduction. Notostracans are [[omnivore]]s living on the bottom of [[temporary pool]]s and shallow lakes.