Amiskwia

Amiskwia sagittiformis is a small and probably gelatinous animal, of uncertain fil- nation, known from the middle Cambrian fossils found on the Burgess shale in British Columbia. Amiskwia sagittiformis is the only species described in the genus.

The state of conservation of the five known specimens leaves much to be desired. The length of the fossil is up to 2.5 centimeters. The head contains two cut tentacles, and the thorax, which is not segmented, has a pair of fins and a flattened tail. The digestive tract runs from the head to almost the tail.

It was first described by paleontologist Charles Doolittle Walcott. Walcott seemed to observe three buccal spines in the fossils, so he first classified them within the quetognatos. Similarly, since Amiskwia did not have the typical thorns and teeth of other fossils from the Burgess shale, the scientists suggested that they should probably belong to the Nemerthians. Conway Morris, who conducted a review of the shale fauna of Burgess during the 1970s, described this animal as the only known species to an unknown edge, as it contains two tentacles near the mouth, rather than the tentacle unique that nemertinos usually have.

It is not a very common animal in the Burgess shale. This fact, together with the presence of fins and tail, suggests that the animal was a swimmer who was accidentally trapped in the thick sedimentary streams that formed the Burgess deposits.

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