Article: Collignoniceratid ammonites from the mid-Turonian of England and northern France

Collignoniceras Breistroffer, 1947 is represented by five species in the mid-Turonian of England and Touraine (the type area of the Turonian stage) in northern France. The cosmopolitan and highly variable type species C. woollgari (Mantell) is shown to be a senior synonym of C. schlueterianum (Laube and Bruder) and C. mexicanum (Bose) amongst others, and shows features indicating that Selwynoceras Warren and Stelck, 1940 (the type species of which S. boreale (Warren), is also redescribed) is a synonym of Collignoniceras sensu stricto. Other species referred to the genus are C. carolinum (d'Orbigny), C. papale (d'Orbigny), C. canthus (Sornay) and C. turoniense (Sornay). Ammonites fleuriausianus d'Orbigny, 1841 is a senior synonym of A. vielbancii d'Orbigny, 1850 and is made the type species of Lecointriceras gen. nov., to which two further species, L. carinatum sp. nov. and L. costatum sp. nov. are also referred.