The Upper Cretaceous phosphates of Morocco preserve one of the world’s most diverse assemblages of mosasaurs, reflecting the adaptive radiation of this clade during the Maastrichtian. Herein, we describe a new mosasaur from these deposits. Although the teeth of this specimen resemble those of ‘Platecarpus’ ptychodon, suggesting referral to this species, we re-examine and ultimately reject the fundamental validity of ‘P.’ ptychodon due to the non-diagnostic nature of its holotype and original diagnosis. We instead designate the new specimen as the holotype of a new genus and species, Gavialimimus almaghribensis, gen. et sp. nov. G. almaghribensis is characterized by a highly elongate snout, highly retracted nares and large supratemporal fenestrae, among other features. Phylogenetic analysis under multiple parsimony-based methods reveals novel substructure within the subfamily Plioplatecarpinae, consistently recovering a clade uniting the new species with Selmasaurus and the enigmatic Goronyosaurus. Synapomorphies of this clade include a highly constricted parietal, with Selmasaurus and Gavialimimus being further united by a broadly excavated medial surface of the quadrate suprastapedial process. The cranial morphology of G. almaghribensis also provides new insight into several aspects of mosasaur evolution and comparative anatomy, including adaptive radiation and niche partitioning in Moroccan marine palaeoecosystems.

http://zoobank.org/urn:lsid:zoobank.org:pub:6896D6EE-2609-4917-A811-904B5AA7A8BB

摩洛哥的上白垩统磷酸盐保存着世界上最多样化的马赛克龙之一，反映了马斯特里赫特时期该进化枝的适应性辐射。在此，我们从这些沉积物中描述了一种新的mosasaur。虽然这个标本的牙齿像那些“的板踝龙属” ptychodon，建议转诊到这个物种，我们重新审视，并最终拒绝“的根本有效性P. ” ptychodon由于它的模式标本和原始诊断的非诊断性质。相反，我们将新标本指定为新属和物种Gavialimimus almaghribensis gen的全型。等。十一月 G. almaghribensis其特点是高度细长的鼻子，高度收缩的鼻孔和巨大的肱骨前上窗孔等。在多种基于简约方法的系统发育分析中，揭示了板栗亚科内的新亚结构，不断恢复了将新物种与Selmasaurus和神秘的Goronyosaurus结合在一起的进化枝。该进化枝的同形亚同包括高度收缩的顶壁，Selmasaurus和Gavialimimus被方形sta上足突的广泛挖掘的内侧表面进一步结合。G. almaghribensis的颅骨形态 还提供了对mosasaur进化和比较解剖学几个方面的新见解，包括摩洛哥海洋古生态系统中的适应性辐射和生态位分配。

http://zoobank.org/urn:lsid:zoobank.org:pub:6896D6EE-2609-4917-A811-904B5AA7A8BB