Pachyrhizodus caninus Cope, 1872 (Teleostei, Crossognathiformes) from the early Turonian of Vallecillo (Mexico)

Marine Fishes (Chondrichthyes, Holocephali, Actinopterygii) From the Upper Cretaceous (Campanian) Rybushka Formation Near Beloe Ozero, Saratov Oblast, Russia

“…Two dentary fragments were identified as Pachyrhizodus sp., and although these are not well enough preserved to be speciated, they are significant because they represent the first confirmation of Pachyrhizodus from the Rybushka Formation in the Saratov Oblast (and very likely the Cretaceous of Russia in general). This genus appears to have had a near circumglob-al distribution during the Cretaceous, as specimens have been identified from Australia (Bartholomai 1969), Europe (Forey 1977), Mexico (Giersch et al 2010), New Zealand (Wiffen 1983), and various states in the USA (Stewart 1900;Applegate 1970;Shimada & Fielitz 2006).…”

Fossil marine vertebrates (Chondrichthyes, Actinopterygii, Reptilia) from the Upper Cretaceous of Akkermanovka (Orenburg Oblast, Southern Urals, Russia)

“…Cope (1875) differentiated the teeth of P. caninus (Kansas, USA) from the type species P. basalis (Sussex, England) by the presence of a “less swollen and more conical [tooth] in radial section”. By this comparison, the new teeth are closest to P. basalis , although the reliability of this character has since been disputed ( Forey, 1977 ; Giersch et al, 2010 ). The European record of Pachyrhizodus comprises P. basalis from the English Chalk Group type locality in Lewes, Sussex (England; Dixon, 1850 ; Forey, 1977 ), articulated skeletons of P. subulidens ( Owen, 1840 ) from the Cenomanian of northeastern Italy ( Amalfitano et al, 2020 ), isolated teeth assigned to cf.…”

“…The teeth described here are confidently identified as belonging to a pachyrhizodontid fish with close dental affinities to the widely distributed genus Pachyrhizodus. Pachyrhizodus is a speciose predatory fish from Upper Cretaceous deposits in Europe, the Western Interior Seaway (USA), as well as Central (Mexico), Southern America, and New Zealand ( Dixon, 1850 ; Cope, 1875 ; Forey, 1977 ; Wiffen, 1983 ; Hakel and Stewart, 2003 ; Everhart, 2005a ; Giersch et al, 2010 ; Otero and Suárez, 2022 ). Although several species have been described, their teeth display only minor variations, meaning that isolated teeth of this genus cannot be reliably assigned to a species.…”

New occurrences of Belonostomus (Teleostomorpha: Aspidorhynchidae) from the Late Cretaceous of the North American Gulf Coastal Plain, USA

“…The youngest record of Belonostomus sp. in Mexico comes from the Vallecillos quarry of the Lower Turonian Agua Nueva Formation (Giersch et al, 2010).…”