Kazacharthra

Kazacharthra
Temporal range: Upper Triassic–Lower Jurassic
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Branchiopoda
Order: Kazacharthra
Novojilov, 1957
Family: Ketmeniidae
Species
  • Ketmenia schultzi
  • Almatium gusevi
  • Iliella spinosa
  • Jeanrogerium sornayi
  • Kungeja tchakabaevi
  • Kysyltamia tchiiliensis
  • Panacanthocaris ketmenia

Kazacharthra is an extinct order of branchiopod crustaceans, 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 in that they are much larger (carapace length ranging from 0.6 to 5 centimeters), having uniquely shaped, heavily sclerotized, heavily mineralized carapaces, and plate-shaped telsons The carapace, or headshield has a distinctive pattern of tubercles, typically with a central-anteriorly located tubercle that may or may not house the compound eyes, and other, distinctively shaped tubercles that may represent attachment sites for mandibles.

There are seven genera recognized, placed within a single family, Ketmeniidae (invalid name/synonym = Paratriopsidae).

References

Paleontology portal
Crustaceans portal