The Vaals Formation in its type area, in southern Limburg, the Netherlands and adjoining Aachen area in Germany, comprises predominantly glauconitic sandy deposits that were laid down in a very shallow, nearshore environment. The early Campanian age assignment (c. 81 Ma) of the Vaals Formation is based primarily on ammonites (in particular Scaphites hippocrepis II–III) and belemnitellid coleoids. All aragonite has been dissolved in strata assigned to the Vaals Formation, and silicified macrofossil assemblages are found at certain levels. The silicification is thought to reflect temporary silica enrichment (by riverine input, or dissolution of sponge spicules or silicoflagellate tests). The most important and species-rich silicified assemblages are known from the so-called ‘Müller's Bed’, just below the Vaalsbroek Horizon and within the Gemmenich Member, in the lower part of the formation. Silicified molluscs, serpulids, scleractinian corals, bryozoans and echinoderms have been described in the past. Now, a temporary exposure (1987) of ‘Müller's Bed’ at Vaals-Eschberg has also produced silicified teleost otoliths. A total of 42 specimens have been recovered from this level, 20 of which could be identified and assigned to seven species, including three new ones; Centroberyx vaalsensis sp. nov. (Beryciformes, Berycidae), Protoholocentrus janjanssensi gen. et sp. nov. and Sillaginocentrus crispus sp. nov. (both Holocentriformes incertae sedis). The faunal composition differs distinctly from coeval otolith associations known from elsewhere in Europe and in North America. The putative holocentriform otoliths are the earliest known to date from the fossil record.

位于荷兰林堡南部和毗邻的德国亚琛地区的 Vaals 组在其典型区域内，主要包括沉积在非常浅的近岸环境中的海绿石砂质沉积物。Vaals 组的坎帕阶早期年龄分配（c . 81 Ma）主要基于菊石（特别是Scaphites hippocrepisII-III) 和芥菜类。所有文石都溶解在分配给瓦尔斯组的地层中，并且在一定水平上发现了硅化的大型化石组合。硅化被认为反映了暂时的二氧化硅富集（通过河流输入，或海绵骨针的溶解或硅鞭毛虫测试）。最重要和物种丰富的硅化组合是从所谓的“Müller's Bed”中知道的，就在 Vaalsbroek 地平线下方和 Gemmenich 段内，在地层的下部。过去曾描述过硅化软体动物、蛇形软体动物、石珊瑚、苔藓虫和棘皮动物。现在，Vaals-Eschberg 的“Müller's Bed”的临时曝光（1987 年）也产生了硅化硬骨鱼耳石。从这个级别共回收了42个标本，Centroberyx vaalsensis sp. 十一月 （Beryciformes，Berycidae），Protoholocentrus janjanssensi gen。等人。十一月 和Sillaginocentrus crispus sp。十一月 （都 Holocentriformes incertae sedis）。动物群组成明显不同于欧洲其他地方和北美已知的同时代耳石协会。假定的全心形耳石是迄今为止从化石记录中已知的最早的耳石。