研究人员报道了唯一已知的来自盾皮鱼纲节甲鱼类的三维矿化心脏、厚壁胃和双叶肝案例，这些都是来自西澳大利亚晚泥盆纪Gogo地层的有颌类。应用同步辐射和中子显微层析技术对这一材料进行分析，显示出平坦的S形心脏，它与肝脏和其他腹部器官很好地分开，并且没有肺。因此，节甲鱼类显示了最早的系统发育证据，表明有颌类心脏的重新定位与有颌脊椎动物复杂颈部区域的演化相关。
据了解，有颌脊椎动物的起源和早期多样化涉及骨骼和软体解剖学的重大变化。骨骼的变化可以通过研究有颌类化石来直接考察；然而，软体解剖学的保存却很罕见。
附：英文原文
Title: Exceptional preservation of organs in Devonian placoderms from the Gogo lagersttte
Author: Kate Trinajstic, John A. Long, Sophie Sanchez, Catherine A. Boisvert, Daniel Snitting, Paul Tafforeau, Vincent Dupret, Alice M. Clement, Peter D. Currie, Brett Roelofs, Joseph J. Bevitt, Michael S. Y. Lee, Per E. Ahlberg
Issue&Volume: 2022-09-16
Abstract: The origin and early diversification of jawed vertebrates involved major changes to skeletal and soft anatomy. Skeletal transformations can be examined directly by studying fossil stem gnathostomes; however, preservation of soft anatomy is rare. We describe the only known example of a three-dimensionally mineralized heart, thick-walled stomach, and bilobed liver from arthrodire placoderms, stem gnathostomes from the Late Devonian Gogo Formation in Western Australia. The application of synchrotron and neutron microtomography to this material shows evidence of a flat S-shaped heart, which is well separated from the liver and other abdominal organs, and the absence of lungs. Arthrodires thus show the earliest phylogenetic evidence for repositioning of the gnathostome heart associated with the evolution of the complex neck region in jawed vertebrates.
DOI: abf3289
Source: https://www.science.org/doi/10.1126/science.abf3289