| Kazacharthra Temporal range: | |
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Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Clade: | Pancrustacea |
| Class: | Branchiopoda |
| Order: | †Kazacharthra Novojilov, 1957 |
| Family: | †Ketmeniidae Novozhilov 1957 |
| Species | |
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Kazacharthra is an extinct order of branchiopod crustaceans that appear to be closely related to the living order Notostraca (the tadpole shrimp). Kazacharthrans lived in marshes and ponds in the Upper Triassic of Western China and Mongolia, and in Lower Jurassic Kazakhstan (where their fossils were first found, hence the name). It is presumed that the kazacharthrids lived much like their living relatives, in that they were opportunistic omnivores that fed on any available food source, from bacterial biofilms to detritus to smaller animals that could be overpowered (i.e., fairy shrimp, small or recently hatched amphibian larvae, smaller members of the same species, etc.).
The kazacharthrans are distinguished from tadpole shrimp by their much larger size (carapace length ranging from 0.6 to 5 centimeters), uniquely shaped, heavily sclerotized and mineralized carapaces, and plate-shaped telsons. The carapace, or headshield, has a distinctive pattern of tubercles, typically including a centrally anteriorly located tubercle that may or may not have housed the compound eyes, as well as other distinctively shaped tubercles that may represent attachment sites for the mandibles.
