Animal evolution transformed microbial mat development. Canonically inferred negative effects include grazing, disturbance and competition for space. In contrast, ancient examples of cooperation between microbial mats and invertebrates have rarely been reported. Late Cambrian (~485 million years) Cryptozoön is widely regarded as the first stromatolite to have received a taxonomic name and has been compared with present‐day examples at Shark Bay, Australia. Here, we show that Cryptozoön is an interlayered consortium of keratose (‘horny’) sponge and microbial carbonate in roughly equal proportions. Cryptozoön's well‐defined layering reflects repeated alternation of sponge and microbial mat. Its distinctive lateral growth is due to the ability of keratosans to colonize steep and overhanging surfaces. Contrary to the perception of Phanerozoic stromatolites as anachronistic survivors in a eukaryotic world, Cryptozoön suggests mutualistic behaviour in which sponges and microbial mats cooperated to gain support, stability and relief, while sharing substrates, bacteria and metabolites. Keratosan‐microbial consortia may have been mistaken for stromatolites throughout the record of the past 500 million years, and possibly longer.

中文翻译：

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'经典叠层石'Cryptozoön是一种角蛋白海绵-微生物联合体

动物进化改变了微生物垫的发展。从规范上可以推断出负面影响包括放牧，干扰和空间竞争。相反，很少有关于微生物垫和无脊椎动物之间合作的古老例子。寒武纪晚期（约4.85亿年）隐岩被广泛认为是第一个获得生物分类学名称的叠层岩，并已与澳大利亚鲨鱼湾的当今实例进行了比较。在这里，我们证明了隐藻是角质海绵（“角质”）和微生物碳酸盐的层状联盟，其比例大致相等。Cryptozoön的清晰的分层反映了海绵和微生物垫的反复交替。其独特的侧向生长归因于角蛋白散落在陡峭且悬垂的表面上的能力。与将生代叠层岩视为真核生物中的过时生物幸存者的看法相反，Cryptozoön提出了相互关系的行为，其中海绵和微生物垫协同工作以获取支持，稳定性和释放力，同时共享底物，细菌和代谢产物。在过去的5亿年的整个记录​​中，Keratosan-微生物联合体可能被误认为是叠层石，并且可能更长。