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Keywords from Image Description:
PZSLPage. Elasmobranch Elasmobranchii sp br Thelodus sp Thelodontidae sp br Psammosteus sp Psammosteida sp br Pteraspis sp Pteraspidae sp br en Scales of elasmobranchs and fossil agnathansbr Vertical section of young integumentbr Vertical section of mature integumentbr Vertical section of integumentbr Surface of head scalesbr Surface