Coral Mushrooms and Mushroom Corals are the Same Organisms: Genetic Confirmation of Close Relationship between Fungiidae Coral and "Coral" Basidiomycota Fungi

Despite striking morphological similarities encoded in common names across multiple languages, the relationship between marine "mushroom corals" (family Fungiidae) and terrestrial "coral mushrooms" (Basidiomycota: Ramaria, Clavulina, Clavariaceae) has been dismissed as superficial convergence for over a century. However, this assumption has never been empirically tested. Using a novel analytical framework that integrates alignment length, sequence identity, and statistical significance, this study performed comprehensive cross-domain sequence analysis of curated ribosomal RNA (18S–28S rDNA) and mitochondrial DNA (mtDNA) datasets from NIH/NCBI and ENA databases. This approach reveals that these organisms are not analogous—they are homologous. Multiple coral fungi yield high-confidence matches to annotated Fungiidae sequences, with rRNA alignments exceeding 1700 bp in length, 84–86% identity, bit scores >1900, and e-values of 0. Significant mtDNA alignments (600–1000+ bp, >70% identity, bit scores >450, e-values <1e-130) emerge consistently from Clavulina, Ramaria, and Clavariaceae representatives. Control sequences from morphologically distinct fungi (Trametes) produce rRNA matches but lack mitochondrial convergence, confirming specificity to coral-form lineages. Reciprocal searches using Fungiidae sequences against fungal databases recover diverse fungal matches, indicating broader genomic affinity between marine "animals" and terrestrial "fungi." These results demonstrate that genomic distinction between mushroom-forming fungi and coral-forming animals does not exist at the resolution examined. The morphological similarities reflect shared evolutionary origin, not convergent evolution. This finding challenges the assumption that fungi and animals represent fully distinct biological kingdoms and reveals a critical blind spot in comparative biology: the failure to systematically test cross-kingdom relationships despite decades of available molecular data and over a century of noted morphological parallels. The evidence demands immediate validation and forces a fundamental question: are we studying biology, or are we studying the taxonomic categories we inherited from the pre-genomic era? Project Data: Journal: https://osf.io/ur79d/ DOI 10.17605/OSF.IO/UR79D Issue One Data: https://osf.io/69whf/ DOI 10.17605/OSF.IO/69WHF