Jaws of ammonites which inhabited the Panboreal Superrealm during the Jurassic and Cretaceous are poorly known in comparison to those of Tethyan ammonoid faunas. This paucity may be explained by limited thickness, or even absence of an outer calcitic layer, in lower jaw elements (aptychi) of Boreal ammonites. Here we describe, for the first time, the jaws (both lower and upper) of ammonites of the Boreal family Polyptychitidae, of Early Cretaceous (Valanginian) age. Polyptychitid lower jaws are of the aptychus type, but have an unusual pointed and convex shape. However, lower jaws of Late Jurassic ancestors of polyptychitids (Craspeditidae) as well as Middle Jurassic cardioceratids (Pseudocadoceras) have a near-identical shape, as do previously described aptychi of the Late Cretaceous genera Neogastroplites and Placenticeras (Hoplitoidea). The close resemblance of lower jaws of evolutionarily distant ammonites may be linked to a similar lifestyle, but more data are needed to substantiate this. Upper jaws of polyptychitid are closely similar to previously described upper jaws of Jurassic ammonites, which indicates the conservatism of this part of the jaw apparatus. Together with shells and jaws of the Valanginian ammonites described herein, jaws of coleoids (likely belemnites) as well as arm hooks (onychites) have been found.

在侏罗纪和白垩纪居住在 Panboreal Superrealm 的菊石的颚与特提斯菊石动物群的颚相比鲜为人知。这种缺乏可能是由于北方菊石的下颌元素（aptychi）厚度有限，甚至没有外部方解石层。在这里，我们首次描述了早白垩纪（Valanginian）时代的北方家族 Polyptychitidae 菊石的颌骨（下颌和上颌）。Polyptychitid 下颌属于 aptychus 类型，但具有不寻常的尖凸形状。然而，侏罗纪晚期息肉科（Craspeditidae）的祖先以及中侏罗纪心脏角类动物（Pseudocadoceras）的下颌具有几乎相同的形状，正如先前描述的晚白垩世属的aptychi一样Neogastroplites和Placenticeras (Hoplitoidea)。进化上遥远的菊石下颌的相似性可能与相似的生活方式有关，但需要更多数据来证实这一点。polyptychitid的上颚与之前描述的侏罗纪菊石的上颚非常相似，这表明这部分颚装置的保守性。连同本文所述的 Valanginian ammonites 的贝壳和颌骨，已经发现了 coleoids 的颌骨（可能是箭石）以及臂钩（onychites）。