A description of the genus
Lambdoceras by
Ruben A. Stirton was published in 1967. It was synonymized subjectively with
Prosynthetoceras by Patton (1969), Patton and Taylor (1971) and Patton and Taylor (1973). It was assigned to
Protoceratidae by Stirton (1967), Tedford et al. (1987) and Albright (1999); and to
Synthetoceratini by Webb (1981), Prothero (1998), Webb et al. (2003) and Prothero and Ludtke (2007). There are three species; the type
Lambdoceras hessei,
L. siouxensis, and
L. trinitiensis. ==References==