| 
                                    
                                        gptkbp:instanceOf
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:extinct_class_of_jawless_fish
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:class
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Osteostraci
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:describedYear
                                    
                                 | 
                                
                                    
                                        
                                            
                                            1868
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:diet
                                    
                                 | 
                                
                                    
                                        
                                            
                                            filter feeder
                                        
                                        
                                         
                                    
                                        
                                            
                                            detritivore
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:discoveredBy
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Lankester
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:distinctiveFeature
                                    
                                 | 
                                
                                    
                                        
                                            
                                            bony head shield
                                        
                                        
                                         
                                    
                                        
                                            
                                            dorsoventrally flattened body
                                        
                                        
                                         
                                    
                                        
                                            
                                            jawless
                                        
                                        
                                         
                                    
                                        
                                            
                                            paired pectoral fins
                                        
                                        
                                         
                                    
                                        
                                            
                                            single external nostril
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:distribution
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Europe
                                        
                                         
                                    
                                        
                                            gptkb:North_America
                                        
                                         
                                    
                                        
                                            gptkb:Russia
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:endangeredStatus
                                    
                                 | 
                                
                                    
                                        
                                            
                                            extinct
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:eyeColor
                                    
                                 | 
                                
                                    
                                        
                                            
                                            dorsal
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:firstAppearance
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Late_Silurian
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:fossilRange
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Devonian
                                        
                                         
                                    
                                        
                                            gptkb:Silurian
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:habitat
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:marine
                                        
                                         
                                    
                                        
                                            
                                            freshwater
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:importantFor
                                    
                                 | 
                                
                                    
                                        
                                            
                                            early vertebrate evolution
                                        
                                        
                                         
                                    
                                        
                                            
                                            evolution of paired fins
                                        
                                        
                                         
                                    
                                        
                                            
                                            insight into jawless vertebrates
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:kingdom
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Animalia
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:lastAppearance
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Late_Devonian
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:notableGenus
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Auchenaspis
                                        
                                         
                                    
                                        
                                            gptkb:Cephalaspis
                                        
                                         
                                    
                                        
                                            gptkb:Hemicyclaspis
                                        
                                         
                                    
                                        
                                            gptkb:Tremataspis
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:notableSite
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Downtonian_beds
                                        
                                         
                                    
                                        
                                            gptkb:Old_Red_Sandstone
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:order
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Cephalaspidida
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:phylum
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Chordata
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:relatedTo
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Anaspida
                                        
                                         
                                    
                                        
                                            gptkb:Gnathostomata
                                        
                                         
                                    
                                        
                                            gptkb:Pteraspidomorphi
                                        
                                         
                                    
                                        
                                            gptkb:Thelodonti
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:respiration
                                    
                                 | 
                                
                                    
                                        
                                            
                                            gill pouches
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:shape
                                    
                                 | 
                                
                                    
                                        
                                            
                                            flattened
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:size
                                    
                                 | 
                                
                                    
                                        
                                            
                                            up to 30 cm
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:skeletonType
                                    
                                 | 
                                
                                    
                                        
                                            
                                            cartilaginous with bony head shield
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:subfamily
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Vertebrata
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:tailLength
                                    
                                 | 
                                
                                    
                                        
                                            
                                            heterocercal
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:bfsParent
                                    
                                 | 
                                
                                    
                                        
                                            gptkb:Cephalaspidomorphi
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        gptkbp:bfsLayer
                                    
                                 | 
                                
                                    
                                        
                                            
                                            6
                                        
                                        
                                         
                                    
                                 | 
                            
                        
                            
                                | 
                                    
                                        https://www.w3.org/2000/01/rdf-schema#label
                                    
                                 | 
                                
                                    
                                        
                                            
                                            Osteostraci
                                        
                                        
                                         
                                    
                                 |