Datovo Aléssio, Johnson G
Museum of Zoology, University of São Paulo, Av. Nazaré, 481, 04263-000 São Paulo, SP, Brazil.
Division of Fishes, MRC 159, Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Sci Adv. 2025 May 2;11(18):eadt1576. doi: 10.1126/sciadv.adt1576. Epub 2025 Apr 30.
Coelacanths are rare fishes that occupy a key evolutionary position in the vertebrate tree of life. Despite being exhaustively studied, we found that a substantial part of the knowledge on their cranial musculature was mistaken. Eleven previously reported coelacanth "muscles" are nonexistent, while three previously unknown muscle subdivisions and connections are found. These findings markedly affect our understanding of the deep-time cranial evolution of jawed vertebrates (gnathostomes). Only 13% of the previously identified myological evolutionary novelties for the major gnathostome lineages proved to be accurate, but several new ones are proposed. We show that low, moderate, and high levels of cranial muscle innovation characterized the emergence of lobe-finned (sarcopterygian), cartilaginous (chondrichthyan), and ray-finned (actinopterygian) fishes, respectively. The novelties in the latter group resulted in the evolution of a second active mechanism for the expansion of the oropharyngeal cavity, which was probably crucial for the predominance of suction feeding versus bite feeding in extant actinopterygians.
腔棘鱼是稀有鱼类，在脊椎动物生命之树中占据关键的进化位置。尽管已被详尽研究，但我们发现关于它们头部肌肉组织的大量知识是错误的。之前报道的11块腔棘鱼“肌肉”并不存在，同时发现了3个先前未知的肌肉细分和连接。这些发现显著影响了我们对有颌脊椎动物（gnathostomes）远古时期头部进化的理解。之前为主要有颌脊椎动物谱系确定的肌学进化新特征中，只有13%被证明是准确的，但提出了几个新的。我们表明，低、中、高水平的头部肌肉创新分别是肉鳍鱼（肉鳍鱼类）、软骨鱼（软骨鱼类）和硬骨鱼（辐鳍鱼类）出现的特征。后一组的新特征导致了口咽腔扩张的第二种主动机制的进化，这可能对现存辐鳍鱼类中吸食摄食相对于咬食的优势至关重要。
