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Kazacharthra
Kazacharthra is an extinct Order (biology), order of branchiopod crustaceans that appear to be closely related to the living Order (biology), 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 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 distinc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 since the Devonian. 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 omnivores living on the bottom of temporary pools and shallow lakes. Description Notostracans are long, with a broad carapace at the front end, and a long, slender abdomen. This gives them a similar overall shape to a tadpole, from which the common name ''tadpole shrimp'' derives. The carapace is dorso-ventrally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
