Where the giants lived: the worlds largest ammonite Parapuzosia and its palaeoenvironment

世界上最大也是最有名的鹦鹉螺化石是来自德国m<s:1> nsterland地区坎帕尼亚（上白垩纪）的Parapuzosia seppenradensis。这个巨人大约。直径2.30米，在120年前被发现。人们对这个标本和这个物种知之甚少，因为巨大的副蜥蜴被认为是极其罕见的。然而，在墨西哥东北部科阿韦拉州的合作活动和实地考察期间，我们在官方和私人收藏中发现了许多标本，并找到了这些巨人的发源地。副翼虫似乎是那里常见的分类单元。为了确定准确的地层范围和沉积时的古环境条件，我们计划对这些地点进行调查。建立精细尺度的生物地层格架，对菊石、虫壳类、浮游有孔虫和纳米化石进行逐层分析，并通过同位素地层学进一步校正这种分带。对收集到的和仍然嵌入的标本进行形态计量学和地形学调查，将使人们深入了解巨型副栉水母的古生物学方面。幼年和成年标本可以首次与来自欧洲和北美的材料进行比较。在墨西哥剖面中发现的与Parapuzosia相关的区系元素（如其他菊石、菊石）将使我们对两个大陆之间的区系关系得出进一步的结论。其中一些分类群也表现出巨人症。因此，我们将讨论这样一个问题，即在圣东尼亚-坎帕尼亚过渡时期，哪些环境条件允许各种海洋软体动物的体型大幅增加。此外，我们的数据将对世界各地展示这个著名的德国化石副本的博物馆感兴趣。此外，该剖面可能是横跨圣安东尼奥-坎帕尼亚边界最完整的剖面之一。

The worlds largest and likely most famous ammonite is Parapuzosia seppenradensis from the Campanian (Upper Cretaceous) of the Münsterland region in Germany. This giant was approx. 2.30 metres in diameter and was discovered 120 years ago. Little is known on the specimen and the species, as giant Parapuzosia were considered to be extremely rare. During cooperation activities and fieldwork in north-eastern Mexican state of Coahuila, however, we discovered numerous specimens in official and private collections and also found the localities, from there these giants originate. Parapuzosia appears to be a common taxon there. Here we plan to investigate these localities in order to determine the precise stratigraphic range and the palaeoenvironmental conditions during deposition. A fine-scaled biostratigraphic framework will be established providing a layer-by-layer analysis of ammonites, inoceramids, planktic foraminifers and nannofossils, and we will further calibrate this zonation by isotope stratigraphy. A morphometric and a taphonomical investigation of collected and still embedded specimens will give insight into palaeobiological aspects of giant Parapuzosia. Juvenile and adult specimens can be compared for the first time with material from both Europe and North America. The faunal elements associated with Parapuzosia (e.g. other ammonites, inoceramids) in the Mexican sections will allow us to draw further conclusions on the faunal relations between both continents. Some of these taxa also show gigantism. We will therefore discuss the question, which environmental conditions allowed for the enormous size increase in various marine molluscs in the Santonian-Campanian transition. In addition, our data will be of interest for museums worldwide that display copies of this famous German fossil. In addition, the section may be one of the completest across the Santonian-Campanian boundary at all.