''Jugatacaris'' is an extinct genus of bivalved arthropod known from a single species, ''Jugatacaris agilis'' found in the

Cambrian Stage 3 Cambrian Stage 3 is the still unnamed third stage of the Cambrian. It succeeds Cambrian Stage 2 and precedes Cambrian Stage 4, although neither its base nor top have been formally defined. The plan is for its lower boundary to correspond approxima ...

aged

Chengjiang biota The Maotianshan Shales () are a series of Early Cambrian sedimentary deposits in the Chiungchussu Formation or Heilinpu Formation, famous for their '' Konservat Lagerstätten'', deposits known for the exceptional preservation of fossilized orga ...

of Yunnan, China. The carapace is around in length, with a pronounced ridge at the top of the carapace separating the two valves, which formed a fin-like structure raised above the carapace. The head has a pair of stalked eyes, as well as a dumbbell shaped medial eye between them. The head also bore a pair of

mandibles In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

as well as at least one and possibly two pairs of antennules. The trunk had up to 65 segments, each with biramous appendages. The appendages had thin endopods with 30 podomeres, each bearing a spiny endite, with the endopods ending with a terminal claw. The appendages also had overlapping flap-like exopods, which are elongated, being at maximum eight times as long as they are wide, which on their posterior edge are covered with

setae In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae ...

. The trunk ended with a forked tail. It was likely an actively swimming

filter feeder Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a s ...

, using its constantly beating appendages to sift food from the water column, which was then passed forward along the U-shaped food groove between the appendage pairs towards the mouth. While initially placed as a crustaceanomorph, later studies considered to be a member of

Hymenocarina Hymenocarina is an Order (biology), order of extinct marine arthropods known from the Cambrian. They possess bivalved carapaces, typically with exposed posteriors. Members of the group are morphologically diverse and had a variety of ecologies, i ...

, which contains numerous other similar bivalved Cambrian arthropods.

References

{{Taxonbar, from=Q113628108 Prehistoric arthropod genera Cambrian arthropods Hymenocarina Fossil taxa described in 2021