Fig. 5. A in Extreme abundance of ammonoids in mass accumulations from the Late Devonian of the Moroccan Anti-Atlas

Fig. 5. A scheme of shell measurements in Cheiloceras sp. from the lower Famennian of Madene El Mrakib, Anti-Atlas, Morocco (PIMUZ 37923). A. Polished sagittal section with the possible continuation of the ammonoid shown in grey. The photographed specimen is incomplete, parts of the body chamber are missing, and the specimen was probably larger as suggested by the reconstructed area. B. The body chamber shown without phragmocone; dashed lines indicate possible positions of the terminal aperture of the ammonoid. The diameter of the largest complete ammonoid from Madene sample and the diameter of the specimen without the body chamber are shown. C. The cross section showing the way the aperture opening was calculated. The number 4.2 is an average value from measurements of different sized specimens; a, apertural height; b, diameter of previous demi-whorl; conch diameter = a + b.图5 产自摩洛哥反阿特拉斯（Anti-Atlas）地区Madene El Mrakib下法门阶的唇石菊石未定种（Cheiloceras sp.）壳体测量方案（藏品编号PIMUZ 37923）。A. 抛光矢状切面，灰色区域标注了该菊石可能的延伸部分。本次拍摄的标本并不完整，部分住室（body chamber）已缺失，且根据重建区域推断，该标本原本尺寸应更大。B. 仅展示住室而移除了气壳（phragmocone）的视图；虚线标注了该菊石终壳口的可能位置。图中同时标注了Madene采样点中最大完整菊石的直径，以及去除住室后的标本直径。C. 展示壳口开口计算方式的横截面图。数值4.2为不同尺寸标本测量所得的平均值；其中a为壳口高度，b为前半旋环直径，壳体直径（conch diameter）= a + b。