Term
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Definition
| ("wing-armor") in addition to general ostracoderm characters, pteraspida show evidence of an olfactory tract and cerebellum. They have head shields formed by fusion of bony plates with the rest of the body covered in scales or small plates. |
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Term
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Definition
| Marine pteraspida. Scales with out dentin |
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Term
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Definition
| Marine pteraspida. Scales with dentin and coated in an enamel-like substance |
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Term
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Definition
| Marine (some freshwater) pteraspida. Scales with dentin. Had fusiform head armor, fan shaped tail, and a single common external branchial opening on each side of the head. |
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Term
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Definition
| ("Muscle-finned") silurian ostracoderms. Differ from pteraspida in that they have paired lateral fin folds as well as dorsal and anal fins. |
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Term
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Definition
| Freshwater Myopterygii that lacked armor, which made them more flexible. Their hypocercal tail suggests they were strong open water swimmers. |
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Term
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Definition
| Myopterygii with tooth-like scales with dentin and enamel-like coating instead of armor. |
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Definition
| Myopterygii with massive head shields. Their mouth and gills were located ventrally suggesting they were bottom dwellers. |
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Term
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Definition
| Myopterygii with very large rostrums (nose). They had a bony skeleton with pectoral fins. |
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Term
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Definition
| Brackish water dwelling Myopterygii that were heavily armored with a large head shield, paired pectoral and dorsal fins, and strong tails. Suggests they were powerful swimmers. Had a bony skeleton, some with stabilizing anterior lobes. Closest known relative to Gnathostomes. |
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