Dal Sasso Cristiano, Pasini Giovanni, Fleury Guillaume, Maganuco Simone
Museo di Storia Naturale di Milano, Milano, Italy.
Appiano Gentile, Como, Italy.
PeerJ. 2017 Jul 4;5:e3481. doi: 10.7717/peerj.3481. eCollection 2017.
Maganuco, Dal Sasso & Pasini, 2006 is a large predatory archosaur from the Middle Jurassic (Bathonian) of the Mahajanga Basin, NW Madagascar. It was diagnosed on the basis of teeth and a fragmentary maxilla, but its affinities were uncertain. Here we describe new cranial remains (above all, an almost complete right premaxilla and a caudally incomplete left dentary) that greatly improve our knowledge on this enigmatic species and reveal its anatomy to be crocodylomorph. The right premaxilla indicates that the rostrum was deep, wide, and not pointed; it bears five teeth that are sub-vertical and just slightly curved lingually; the mesial teeth are U-shaped in cross-section and have serrated carinae on the lingual side; the (external bony nares) are confluent and face rostrally; and there is no lateral groove at the premaxillomaxillary suture for reception of a hypertrophied lower caniniform tooth. The preserved portion of the left dentary has an edentulous tip and bears eight large mandibular teeth of which the mesial (1-3) are the largest, but none is a hypertrophied caniniform tooth; the mandibular (dentary) symphysis extends caudally to the level of the third tooth; the splenial is not preserved, but its sutural marks on the dentary indicate that it contributed to the mandibular symphysis for at least 20% of the symphyseal length in dorsal aspect. On the basis of this new data, some previously uncertain features of the holotype maxilla-such as the margin of the suborbital fenestra, the contact surfaces for the palatine, the ectopterygoid, and the jugal-are now apparent. Testing of the phylogenetic position of the species within Crocodylomorpha indicates that is a mesoeucrocodylian. It also represents one of the earliest events of exacerbated increase in body size along the evolutionary history of the group. In addition, it is by far the oldest notosuchian. A cranial reconstruction of this gigantic predator is also attempted here. The very robust jaw bones of , coupled with its peculiar dentition, strongly suggest a diet that included hard tissue such as bone and tendon.
马加努科鳄、达尔·萨索鳄与帕西尼鳄（2006年命名）是一种大型掠食性主龙类，来自马达加斯加西北部马哈赞加盆地的中侏罗世（巴通阶）。它是根据牙齿和一块不完整的上颌骨来鉴定的，但其亲缘关系尚不确定。在此，我们描述了新发现的颅骨化石（最重要的是，一块几乎完整的右前上颌骨和一块尾端不完整的左齿骨），这极大地增进了我们对这个神秘物种的了解，并揭示出它的解剖结构属于鳄形类。右前上颌骨显示吻部深、宽且不尖；它有五颗牙齿，呈近垂直状，仅略微向舌侧弯曲；内侧牙齿的横截面呈U形，舌侧有锯齿状的嵴；外鼻孔汇合且朝前；前上颌骨与上颌骨的缝合处没有用于容纳肥大下犬齿状牙齿的侧沟。左齿骨的保存部分前端无齿，有八颗大的下颌牙齿，其中内侧的（第1 - 3颗）最大，但没有一颗是肥大的犬齿状牙齿；下颌联合部向后延伸至第三颗牙齿的位置；夹板骨未保存，但它在齿骨上的缝合痕迹表明，在背侧观中，它对下颌联合部的贡献至少占联合部长度的20%。基于这些新数据，正模上颌骨一些先前不确定的特征，如眶下孔的边缘、与腭骨、外翼骨和颧骨的接触面，现在变得清晰了。对该物种在鳄形类中的系统发育位置进行的测试表明，它是一种中真鳄类。它还代表了该类群进化史上最早的体型急剧增大事件之一。此外，它是迄今为止最古老的诺托鳄类。在此还尝试对这种巨型掠食者进行颅骨重建。马加努科鳄非常粗壮的颌骨，加上其独特的齿列，强烈表明其饮食包括骨头和肌腱等硬组织。
