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2 Acta Geologica Polonica

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Interrelationships of Mesozoic hybodont sharks as indicated by dental morphology - preliminary results

Rees J.

Acta Geologica Polonica

2008

Vol. 58, no. 2

217-221

As many hybodont sharks are known solely from their teeth, this investigation approaches the phylogeny of the group with an emphasis on tooth morphology and dentitional patterns. The preliminary results presented here suggest that at least four different lineages of hybodont sharks occurred in the Mesozoic. Dentitional characters imply a close relationship within the Lonchidiidae (Lonchidion, Vectiselachos, Parvodus, and tentatively Hylaeobatis), within the Hybodontinae (Hybodus and Egertonodus) and in another, unnamed subfamily of the Hybodontidae, including Planohybodus, Secarodus and Priohybodus. There is also weak support for a grouping of Acrodus, Asteracanthus and Palaeobates in the Acrodontinae, while Lissodus is left without family designation due to a rather unique dentition and cephalic spine morphology. "Polyacrodus" is considered a nomen dubium as there are no characters to diagnose the genus based on the type species.

Famennian chondrichthyans from the shelves of North Gondwana

Ginter M., Hairapetian V., Klug C.

Acta Geologica Polonica

2002

Vol. 52, nr 2

169-215

Ichthyoliths, mainly shark teeth, from the Famennian of Iran and Northwest Africa are described. Evolution of shallow-water chondrichthyan assemblages on the shelves of Central Iran and the Tafilalt Platform, Morocco, related to time and environmental changes, is discussed. Four new taxa, viz. Deihim mansureae gen. et sp. nov. Protacrodus serra sp.nov., Phoebodus depressus sp. nov., and Ph. gothicus transitans subsp. nov. are erected and provisional reconstructions of heterodonty in dentitions of several Famennian sharks are proposed.