Glossary entry - List of taxa
Arthropoda - arthropods > Trilobita - trilobites > Phacopida > Calymenidae
Flexicalymene retrorsa (Foerste, 1910)
Hemichordata - hemichordates > Pterobranchia > Dendroidea > Mastigograptidae
Mastigograptus perexilis Ruedemann, 1947