The lithostratigraphy, biostratigraphy, sequence stratigraphy, ammonite and inoceramid faunas of the Upper Albian, Cenomanian, Lower Turonian Karai Formation, highest unit Uttatur Group in the Pondicherry Sub-Basin Cauvery Basin Tamil Nadu, south India, are documented. Detailed logs and descriptions sections between Kulakkalnattam, Odiyam Kunnam, north-west of Garudamangalam presented. They pro...

In sections of the Achdorf Formation at Wochenberg hill (western Swabian Alb, SW Germany), a succession five ammonite biohorizons is distinguished (from bottom to top): crassicostatum and viallii Lower Aalenian (Bifidatum Subzone, Opalinum Zone) latiumbilicus , discoidea α β Upper (Murchisonae Murchisonae Zone). The herein newly introduced biohorizon youngest hitherto identified Zone Subzone). ...

Bivalve, ammonite and snail shells are described by a small number of geometrical parameters. Raup noted that the vast majority of theoretically possible shell forms do not occur in nature. The constraint factors that regulate the biased distribution of natural form have long since been an open problem in evolution. The problem of whether natural shell form is a result of optimization remains u...

New data on the ammonite genus Pseudokossmaticeras Spath, 1922 have been obtained from several uppermost Campanian–lower Maastrichtian strata of Fore-Balkan Mountains (Bulgaria). A review earlier Bulgarian records is also presented. The following species are here described and illustrated: brandti (Redtenbacher, 1873), P. galicianum (Favre, 1869), muratovi Michailov, 1951 tercense (Seunes, 1892...