[1] The genus Triops can be distinguished from the only other living genus of Notostraca, Lepidurus, by the form of the telson (the end of its 'tail'), which bears only a pair of long, thin caudal extensions in Triops, while Lepidurus also bears a central platelike process.

[2] Molecular clock estimates suggest that Triops split from Lepidurus during the Triassic or Jurassic, between 152.3–233.5 million years ago.

[6] The putative Lower Permian subspecies of Triops cancriformis from France has also been redescribed as a separate notostracan taxon, Heidiops permiensis.

Most species reproduce sexually, but some populations are dominated by hermaphrodites which produce internally fertilised eggs.

[11] The diapause also prevents the eggs from hatching too soon after rain; the pool must fill with enough water for the dormancy to be broken.

[12] The head of T. longicaudatus bears a pair of dorsal compound eyes that lie close to each other and are nearly fused together.

Franz von Paula Schrank was the first author to use the genus name Triops,[13] coining it in his 1803 work on the fauna of Bavaria.

In his 1955 taxonomic review of the Notostraca, Alan R. Longhurst supported Keilhack's genus name Triops over Apus.

[13] The International Commission on Zoological Nomenclature (ICZN) followed Longhurst in their 1958 ruling on the usage and origin of the genus names Triops and Apus.

T. longicaudatus is considered a human ally against the West Nile virus, as the individuals consume Culex mosquito larvae.

In Wyoming, the presence of T. longicaudatus usually indicates a good chance of the hatching of American spadefoot toads.