This second edition by Carole Burrow has been extensively expanded and updated. The first edition of volume 5 on Acanthodii was published in 1979 by a well-known palaeoichthyologist, Robert Denison. Many new taxa have been published in the last 40-some years, and more importantly, the interpretation of phylogenetic relationships of the acanthodians within the group and with other gnathostomes has changed, with even the taxon Acanthodii in doubt as a monophyletic unit. The affinity of acanthodians either with chondrichthyans or osteichthyans was not decided in the 1970s and 1980s, whereas today the consensus is that they are placed at the base of the chondrichthyans. No doubt the final word has not yet been written regarding their relationships, but a synthesis of the new and old ideas are presented here by the person with the broadest and best knowledge of acanthodians today.
General Morphology (p. 8)
Body size and shape (p. 8)
Anatomy (p. 8)
Neurocranium and splanchnocranium (p. 8)
Postbranchial endoskeleton (p. 12)
Dermal skeleton (p. 13)
Head, branchial, and pectoral regions (p. 13)
Dentition (p. 15)
Postcranial skeleton (p. 17)
Fins and fin spines (p. 17)
Squamation (p. 19)
Sensory canal system (p. 23)
Histology (p. 23)
Dentition (p. 23)
Fin spines (p. 24)
Scales (p. 26)
Soft anatomy (p. 28)
Habitats, Taphonomy, and Adaptations (p. 30)
Biostratigraphy (p. 32)
Relationships (p. 33)
Classification and Phylogeny (p. 33)
Systematics (p. 36)
Chondrichthyes (p. 36)
Subclass Acanthodii (p. 36)
Order Ischnacanthiformes (p. 36)
Family Acritolepidae (p. 36)
Family Ischnacanthidae (p. 40)
Family Podoliacanthidae (p. 46)
Family Poracanthodidae (p. 47)
Order Ischnacanthiformes (p. 51)
Family incertae sedis (p. 51)
Order Diplacanthiformes (p. 52)
Family Culmacanthidae (p. 52)
Family Diplacanthidae (p. 53)
Family Gladiobranchidae (p. 58)
Family incertae sedis (p. 59)
Order Acanthodiformes (p. 61)
Family Mesacanthidae (p. 62)
Family Cheiracanthidae (p. 65)
Family Howittacanthidae (p. 69)
Family Acanthodidae (p. 70)
Family incertae sedis (p. 78)
Order Tchunacanthida (p. 78)
Family Lenacanthidae (p. 78)
Family Tchunacanthidae (p. 80)
Family incertae sedis (p. 80)
Acanthodii, Order incertae sedis (p. 80)
Family Euthacanthidae (p. 80)
Family Machaeracanthidae (p. 82)
Family Vesperaliidae (p. 85)
Order and family incertae sedis (p. 86)
Acanthodian form taxa (p. 86)
Taxa based on teeth (p. 101)
Taxa based on fin spines (p. 102)
Stem Chondrichthyes (p. 104)
Order incertae sedis (p. 104)
Family Brochoadmonidae (p. 104)
Family Climatiidae (p. 104)
Family Gyracanthidae (p. 107)
Family Kathemacanthidae (p. 112)
Family Sinacanthidae (p. 113)
Family incertae sedis (p. 114)
Doubtfully or certainly not Acanthodii (p. 117)
References and Bibliography (p. 118)
Abbreviations used in Figures (p. 131)
Abbreviations used in Text (p. 131)
Abbreviations of Institutions (p. 132)
Index of Genera (p. 133)
Index of Higher Categories (p. 135)