Hendrickx Christophe, Araújo Ricardo, Mateus Octávio
Departamento de Ciências da Terra, Universidade Nova de Lisboa, GeoBioTec, Faculdade de Ciências e Tecnologia , Caparica , Portugal ; Museu da Lourinhã , Lourinhã , Portugal ; Current affiliation: Evolutionary Studies Institute, Center of Excellence in Palaeosciences, University of the Witwatersrand , South Africa.
Museu da Lourinhã , Lourinhã , Portugal ; Huffington Department of Earth Sciences, Southern Methodist University , Dallas, TX , USA ; Instituto Superior Técnico, Universidade de Lisboa , Lisboa , Portugal ; Museum für Naturkunde , Berlin , Germany.
PeerJ. 2015 Sep 17;3:e1245. doi: 10.7717/peerj.1245. eCollection 2015.
The quadrate of reptiles and most other tetrapods plays an important morphofunctional role by allowing the articulation of the mandible with the cranium. In Theropoda, the morphology of the quadrate is particularly complex and varies importantly among different clades of non-avian theropods, therefore conferring a strong taxonomic potential. Inconsistencies in the notation and terminology used in discussions of the theropod quadrate anatomy have been noticed, including at least one instance when no less than eight different terms were given to the same structure. A standardized list of terms and notations for each quadrate anatomical entity is proposed here, with the goal of facilitating future descriptions of this important cranial bone. In addition, an overview of the literature on quadrate function and pneumaticity in non-avian theropods is presented, along with a discussion of the inferences that could be made from this research. Specifically, the quadrate of the large majority of non-avian theropods is akinetic but the diagonally oriented intercondylar sulcus of the mandibular articulation allowed both rami of the mandible to move laterally when opening the mouth in many of theropods. Pneumaticity of the quadrate is also present in most averostran clades and the pneumatic chamber-invaded by the quadrate diverticulum of the mandibular arch pneumatic system-was connected to one or several pneumatic foramina on the medial, lateral, posterior, anterior or ventral sides of the quadrate.
爬行动物和大多数其他四足动物的方骨通过使下颌骨与颅骨相连，发挥着重要的形态功能作用。在兽脚亚目中，方骨的形态特别复杂，在不同的非鸟类兽脚亚目分支中差异很大，因此具有很强的分类学潜力。人们已经注意到在讨论兽脚亚目方骨解剖学时所使用的符号和术语存在不一致的情况，包括至少有一次，同一结构被赋予了不少于八个不同的术语。本文提出了每个方骨解剖实体的标准化术语和符号列表，目的是便于今后对这块重要颅骨的描述。此外，还概述了关于非鸟类兽脚亚目方骨功能和充气性的文献，并讨论了从这项研究中可以得出的推论。具体来说，绝大多数非鸟类兽脚亚目的方骨是不动的，但下颌关节的斜向髁间沟使许多兽脚亚目动物在张口时下颌的两支都能向外侧移动。大多数坚尾龙类分支的方骨也具有充气性，被下颌弓充气系统的方骨憩室侵入的充气腔与方骨内侧、外侧、后侧、前侧或腹侧的一个或几个气孔相连。
