Latil et al., 2023 - Beudanticeras

[mhorn]

Latil J.L., Murphy M.A., Rodda P.U. (2023) A review of Beudanticeras Hitzel, 1902 (Cretaceous Ammonitida), and its occurrence in the Cottonwood District of Northern California // Paleontología Mexicana. Vol. 12. num. 2. P. 73-86.

http://www.ojs-igl.unam.mx/index.php/Pa ... ew/697/704

Beudanticeras Hitzel is a distinctive but relatively rare Upper Albian (Cretaceous) ammonite that has been reported from the southeast France and the Cottonwood District of northern California coastal ranges. In both iterations of the Treatise (Wright, 1957 and 1996), it has been placed in the Desmoceratidae even though the type species has none of its characteristics. We classify it as the sole genus in the Family Beudanticeratidae Breistroffer, 1953 (nomen translatum herein, ex Beudanticeratinae Breistroffer, 1953) which is characterized by its discoidal shape, narrow umbilicus with an angulate shoulder, sickle-shaped ornamentation, and strongly asymmetrically bifid L. Most discoidal ammonites identified as “Beudanticeras” have features characteristic of the Desmoceratidae, such as, constrictions and trifid L, and are classified in Roberticeras, new genus. Beudanticeras and Cleoniceras are similar with respect to shell shape and strongly asymmetrically bifid suture but significantly different with respect to ornament, and shell shape. Four species are assigned to Beudanticeras: B. beudanti (Brongniart, 1822) and B. sphaerotum (Seeley, 1866) from Europe, B. haydeni (Gabb, 1864) from California, and B. sutherlandbrowni (McLearn, 1972) from British Columbia. B. haydeni (Gabb, 1864), based on a specimen from the Cottonwood district, occurs only in uppermost Albian strata, and can be distinguished from the similar B. beudanti by differences of degree in the umbilicus and ornament.