An international research team has discovered musculature fossils dating back some 535 million years to the early Cambrian Age in China.

The team of paleontologists has reported their discovery of the microfossils, which have preserved the introvert musculature of cycloneuralians, a group of animals that includes roundworms, horsehair worms and mud dragons.

The study was led by Zhang Huaqiao, a researcher at the Chinese Academy of Sciences' Nanjing Institute of Geology and Palaeontology, and published online on Wednesday in the journal Proceedings of the Royal Society B: Biological Sciences.

One of the three phosphatized and millimeter-scale specimens found in the south of Shaanxi Province is better preserved than the others, consisting of five increasingly large rings that are connected with 19 radial and 36 longitudinal structures, Zhang said.

The rings are compressed to varying degrees, implying the cycloneuralians were flexible when alive. This musculature would have facilitated movement and feeding, according to Zhang.

"Early animal muscle fossils have provided an important basis for our understanding of the evolution of locomotion. Through these fossils, we can learn how animals moved in ancient times and how they gradually developed the locomotor skills they have now," he said.
一个国际研究小组在中国发现了大约5 . 35亿年前寒武纪早期的肌肉组织化石。

古生物学家小组报告了他们发现的微体化石，这些微体化石保存了环神经纲动物的内向肌肉组织，这是一组包括蛔虫、马鬃虫和泥龙在内的动物。

这项研究由中国科学院南京地质古生物研究所的研究员张化桥领导，并于周三在《皇家学会学报B:生物科学》杂志上发表。

张说，在陕西省南部发现的三个磷化和毫米级标本中，有一个比其他标本保存得更好，由五个越来越大的环组成，这些环与19个径向和36个纵向结构相连。

这些环受到不同程度的压缩，这意味着cycloneuralians活着的时候是灵活的。根据张的说法，这种肌肉组织有助于运动和进食。

“早期动物肌肉化石为我们理解运动进化提供了重要基础。通过这些化石，我们可以了解动物在古代是如何移动的，以及它们是如何逐渐发展出现在拥有的运动技能的，”他说。