| Protocaris Temporal range:   | |
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| P. marshi | |
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| Holotype specimen | |
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| Genus: | Protocaris  | 
| Species: | Protocaris marshi  | 
Protocaris marshi is an extinct species of bivalved arthropod known from a single specimen collected from the Cambrian Series 2 aged Parker Formation from the Parker Quarry of northwestern Vermont, United States. [2] [3] The specimen is preserved in top-down view and has a bivalved carapace, a segmented trunk and a forked tail. Its precise taxonomic position is uncertain, due to the limited nature of known remains, but it is suggested to be a member of Hymenocarina belonging to the family Protocarididae, which also includes Tokummia and Branchiocaris. [4]