Campyloprion Eastman, 1902 is a chondrichthyan having an arched symphyseal tooth whorl similar to that of

Helicoprion Karpinsky, 1899, but less tightly coiled. The holotype of Campyloprion annectans Eastman, 1902,

the type species of Campyloprion, is of unknown provenance, but is presumed to be from the Pennsylvanian

of North America. Campyloprion ivanovi (Karpinsky, 1922) has been described from the Gzhelian of Russia.

A partial symphyseal tooth whorl, designated as Campyloprion cf. C. ivanovi, is reported from the Missourian

Tinajas Member of the Atrasado Formation of Socorro County, New Mexico, USA. Partial tooth whorls from

the Virgilian Finis Shale and Jacksboro Limestone Members of the Graham Formation of northern Texas, USA,

are designated as Campyloprion sp. Two partial tooth whorls from the Gzhelian of Russia that were previously

referred to C. ivanovi are designated as Campyloprion cf. C. annectans. The age of Toxoprion lecontei (Dean,

1898), from Nevada, USA, is corrected from the Carboniferous to the early Permian. An alternative interpretation

of the holotype of T. lecontei is presented, resulting in a reversal of its anterior-to-posterior orientation. The

genera Helicoprion, Campyloprion, and Shaktauites Tchuvashov, 2001 can be distinguished by their different

spiral angles.

Very rare chondrichthyan spines from the Famennian (Upper Devonian) of European Russia are referred here to ctenacanthiforms, euselachians and a chondrichthyan group of uncertain systematic position. Ctenacanthus Agassiz, 1837 is recorded from the lower and middle Famennian of the central and north-western parts of the area. Sculptospina makhlaevi Lebedev gen. et sp. nov. originates from the lower Famennian of the Lipetsk Region. The holotype of ‘Ctenacanthus’ jaekeli Gross, 1933 and a new specimen from the upper Famennian of the South Urals are shown to belong to the same taxon, which is transferred to Acondylacanthus St. John and Worthen, 1875. New specimens of Tuberospina nataliae Lebedev, 1995 from the upper Famennian of Central Russia are described in detail. The newly presented material increases our knowledge of the composition of Famennian marine assemblages from the East European Platform. It is suggested that these assemblages may be classified as chondrichthyan-dominated and dipnoan-dominated. Hypothetically, after the end- Devonian Hangenberg extinction event, which affected numerous secondary consumers in vertebrate communities, some chondrichthyan groups could have encroached to take advantage of previously occupied ecological niches. Ctenacanthus, as well as Acondylacanthus and Amelacanthus survived the end-Devonian mass extinction to continue into the Carboniferous.

The Oligocene (Rupelian) Byram Formation (Vicksburg Group) in Alabama, USA, is divided into three members, including (in ascending order) the Glendon Limestone, unnamed marl, and the Bucatunna Clay. The Oligocene marine units in Alabama have been historically under-investigated, but bulk samples recently obtained from Glendon Limestone Member exposures at site AWa-9 in Washington County yielded 20 unequivocal elasmobranch and teleost taxa. This surprisingly diverse paleofauna, based on isolated teeth, bones and otoliths, includes the new taxon, Gobiosoma? axsmithi sp. nov., as well as “Aetomylaeus” sp., Albula sp., Aplodinotus gemma Koken, 1888, Ariosoma nonsector Nolf and Stringer, 2003, Balistidae indet., Citharichthys sp., Myliobatoidei indet., Diretmus? sp., Hemipristis sp., Negaprion aff. N. gilmorei (Leriche, 1942), Pachyscyllium sp., Paralbula sp., Physogaleus sp., Preophidion meyeri (Koken, 1888), Sciaena pseudoradians (Dante and Frizzell in Frizzell and Dante, 1965), Sciaenops? sp., Sparus? elegantulus Koken, 1888, Sphyraena sp., and Syacium sp. Additional remains were recovered but could not be identified beyond undetermined Elasmobranchii or Teleostei. All these taxa represent first occurrences within the Glendon Limestone Member in Alabama, and the “Aetomylaeus” sp., Pachyscyllium sp., Paralbula sp., and Sciaenops? sp. specimens represent the first occurrences of each in the Oligocene of the Gulf Coastal Plain of the USA. We also report the first record of Oligocene Paralbula Blake, 1940 teeth, and the first occurrence of an Oligocene member of the Balistidae in the Western Hemisphere. This marine vertebrate assemblage indicates that the Glendon Limestone Member at site AWa-9 represented a subtropical to temperate, middle shelf paleoenvironment with a paleowater depth interpreted as 30–100 m.