Flatworms
| |
| Kingdom: | Animalia |
|---|---|
| Subkingdom: | Eumetazoa |
| Clade: | ParaHoxozoa |
| Clade: | Bilateria |
| Clade: | Nephrozoa |
| Unranked: | Protostomia |
| Unranked: | Spiralia |
| Clade: | Rouphozoa |
| Phylum: | Platyhelminthes |
| Source: Integrated Taxonomic Information System | |
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! Cnidocytes
| Yes || colspan="3" | No
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! Colloblasts
| No || Yes || colspan="2" | No
! Bilateral symmetry
| colspan="2" | No || colspan="2" | Yes
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! Number of main cell layers
| colspan="2" | Two, with jelly-like layer between them || colspan="2" | Three
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! Distinct brain
| colspan="2" | No || colspan="2" | Yes
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! Specialized digestive system
| colspan="2" | No || colspan="2" | Yes
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! Specialized excretory system
| colspan="2" | No || colspan="2" | Yes
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! Body cavity containing internal organs
| colspan="3" | No || Yes
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! Specialized circulatory and respiratory organs
| colspan="3" | No || Yes
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