For more than a century, a number of ammonite taxa of supposed Tethyan origin or affinity have been reported from the Berriasian condensed deposits of Russia (referred to as ‘Ryazanian’). These occurrences have been used to constrain long-distance correlation and palaeobiogeographic interpretation of the Russian Platform during the earliest Cretaceous. We revise these taxa herein. To accommodate the systematic issues, we introduce a new ammonite genus: Mittaites n. gen. (type species: Mazenoticeras ceccai). We also provide re-assessment for the genera Tauricoceras (= Subriasanites), Riasanella, Riasanites, Prorjasanites, and Karasyazites. Considering the strong affinities between these genera (except for Karasyazites), resctricted palaeobiogeographic distribution and a problematic phyletic origin, we erect a new family Riasanitidae n. fam. Our re-examination suggests that the occurrence of western Tethyan migrants in the type ‘Ryazanian’ should be ruled out. Pending new investigation, correlation of the ammonites of the type ‘Ryazanian’ beds with the Berriasian part of the Standard Mediterranean Ammonite Scale (SMAS) should be treated with caution.

一个多世纪以来，从俄罗斯的 Berriasian 凝缩矿床（称为“梁赞”）中报道了许多假定起源于特提斯人或亲缘关系的菊石类群。在最早的白垩纪期间，这些事件已被用于限制俄罗斯地台的长距离相关性和古生物地理解释。我们在此修订这些分类群。为了适应系统性问题，我们引入了一个新的菊石属：Mittaites n。将军 （类型种：Mazenoticeras ceccai）。我们还提供对Tauricoceras (= Subriasanites )、Riasanella、Riasanites、Prorjasanites和Karasyazites属的重新评估. 考虑到这些属之间的强烈亲缘关系（除了Karasyazites）、受限的古生物地理分布和有问题的系统起源，我们建立了一个新的家族 Riasanitidae n。家庭。我们的重新检查表明，应该排除“梁赞人”类型的西特提斯移民的发生。在进行新的调查之前，应该谨慎对待“梁赞期”类型的菊石与标准地中海菊石等级 (SMAS) 的 Berriaasian 部分的相关性。