Vol. 55, No. 9, 2021

Paleontological Journal

Foreword

New Siluro-Devonian Anomalocystitids (Echinodermata, Stylophora) from Bolivia and Canada, and a Reevaluation of Skeletal Homologies in Mitrates

B. Lefebvre and W. I. Ausich p. 932 abstract

Evolution, Functional Morphology and Paedomorphism in the Gogiid-Ascocystitid Lineage (Eocrinoidea; Cambrian-Ordovician)

R. L. Parsley p. 966 abstract

Bolboporites: Interpretation Getting Back on Track

V. B. Kushlina and S. V. Rozhnov p. 977 abstract

Sea Lilies in Spring: Crinoid Diversification during the Early Ordovician

T. E. Guensburg, J. Sprinkle, R. Mooi, F. Gahn and B. Lefebvre p. 985 abstract

Two Coils in the Morphology of Myelodactylids (Crinoidea, Disparida): the Morphogenetic Basis of Their Formation and Adaptation Potential

S. V. Rozhnov p. 993 abstract

An Unusual Cladid (Crinoidea, Echinodermata) from the Pennsylvanian of the Staritsa District (Tver Region)

G. V. Mirantsev p. 1013 abstract

Sea Lilies of the Genus Bathycrinus (Crinoidea, Bathycrinidae) from the Yap and Palau Trenches

A. N. Mironov, D. Zhang and C. Wang p. 1019 abstract

The Axial Complex of Echinoderms Represents the Kidney and Is Homologous to the Hemichordate Heart-Kidney

O. V. Ezhova and V. V. Malakhov p. 1029 abstract

Traces of Sublethal Injuries in Upper Cretaceous Echinoid Tests from the Vicinity of Volsk (Lower Volga Region)

E. A. Kalyakin p. 1039 abstract

Ecological Features of Echinoderm Distribution in the Latorp and Volkhov Regional Stages of the Lower and Middle Ordovician of the Leningrad Region

G. A. Anekeeva p. 1049 abstract

A Review on Knowledge and Research of Interstitial Sea Cucumber

S. P. Woo, S. H. Tan, I. Nooraini, A. Jaya-Ram and T. Fujita p. 1063 abstract