Kazacharthra is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

branchiopod Branchiopoda, from Ancient Greek βράγχια (''bránkhia''), meaning "gill", and πούς (''poús''), meaning "foot", is a class of crustaceans. It comprises fairy shrimp, clam shrimp, Diplostraca (or Cladocera), Notostraca, the Devonian ...

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s that appear to be closely related to the living

Notostraca The order Notostraca, containing the single family Triopsidae, is a group of crustaceans known as tadpole shrimp or shield shrimp. The two genera, ''Triops'' and ''Lepidurus'', are considered living fossils, with similar forms having existed since ...

(the tadpole shrimp). Kazacharthrans lived in marshes and ponds in the Upper

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

of Western

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

and

Mongolia Mongolia is a landlocked country in East Asia, bordered by Russia to the north and China to the south and southeast. It covers an area of , with a population of 3.5 million, making it the world's List of countries and dependencies by po ...

, and in Lower

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...

(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

omnivore An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize t ...

s that fed on any available food source, from

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

biofilm A biofilm is a Syntrophy, syntrophic Microbial consortium, community of microorganisms in which cell (biology), cells cell adhesion, stick to each other and often also to a surface. These adherent cells become embedded within a slimy ext ...

s to

detritus In biology, detritus ( or ) is organic matter made up of the decomposition, decomposing remains of organisms and plants, and also of feces. Detritus usually hosts communities of microorganisms that colonize and decomposition, decompose (Reminera ...

to smaller

animal Animals are multicellular, eukaryotic organisms in the Biology, biological Kingdom (biology), kingdom Animalia (). With few exceptions, animals heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, ...

s that could be overpowered (i.e.,

fairy shrimp Anostraca is one of the four orders of crustaceans in the class Branchiopoda; its members are referred to as fairy shrimp. They live in vernal pools and hypersaline lakes across the world, and they have even been found in deserts, ice-covered mou ...

, small or recently hatched amphibian larvae, smaller members of the same species, etc.). The kazacharthrans are distinguished from

tadpole shrimp The order Notostraca, containing the single family Triopsidae, is a group of crustaceans known as tadpole shrimp or shield shrimp. The two genera, '' Triops'' and ''Lepidurus'', are considered living fossils, with similar forms having existed sinc ...

in that they were much larger (carapace length ranging from 0.6 to 5 centimeters), had uniquely shaped, heavily sclerotized, heavily mineralized carapaces, and plate-shaped telsons. The carapace, or headshield had a distinctive pattern of tubercles, typically with a central-anteriorly located tubercle that may or may not have housed the compound eyes, and other, distinctively shaped tubercles that may represent attachment sites for mandibles.

Taxonomy

There are seven genera recognized, placed within a single family and order. * Order Kazacharthra Novojilov 1957 ** Family Ketmeniidae Novozhilov 1957 aratriopsidae Chernyshev 1940 *** Genus '' Ketmenia'' Chernyshev 1940 **** '' Ketmenia schultzi'' Chernyshev 1940 *** Genus '' Almatium'' Novozhilov 1957 **** '' Almatium gusevi'' Novozhilov 1957 *** Genus '' Iliella'' Chernyshev 1940 **** ''

Iliella spinosa ''Iliella spinosa'' is an extinct species of kazacharthran branchiopod crustaceans from the Lower Jurassic of Kazakhstan. It had a unique carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal group ...

'' Chernyshev 1940 *** Genus '' Jeanrogerium'' Novojilov 1960 **** '' Jeanrogerium sornayi'' Novojilov 1960 *** Genus '' Kungeja'' Novozhilov 1957 **** '' Kungeja tchakabaevi'' Novozhilov 1957 *** Genus '' Kysyltamia'' Novozhilov 1957 **** '' Kysyltamia tchiiliensis'' Novozhilov 1957 *** Genus '' Panacanthocaris'' Novozhilov 1957 **** '' Panacanthocaris ketmenia'' Novozhilov 1957

References

{{Taxonbar, from=Q3814101 Branchiopoda Triassic crustaceans Jurassic crustaceans