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| Chalk Group | Malacostracans | Cirripedes |
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| Crinoids | Asteroids | Ophiuroids |
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TERMINOLOGY |
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| Chalk Group | Malacostracans | Cirripedes |
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| Crinoids | Asteroids | Ophiuroids |
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| Echinoid Spines | Regular Echinoids | Irregular Echinoids | |
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| Elasmobranchs | Chimaeras | ||