The phyla making up the major animal clade of Spiralia have been clear since the advent of molecular phylogenetics; the relationships between these spiralian phyla have not. The lack of consensus over the relationships between these important animal phyla might be a clue implying their emergence in an explosive radiation. Focusing on the five largest spiralian phyla (Annelida, Brachiopoda, Mollusca, Nemertea and Platyhelminthes) and using two phylogenomic datasets, we have applied site-bootstrapping and taxon-jackknifing to explore this example of taxonomic instability. Analyses on the 105 possible rooted trees relating them showed that interphylum branches are very short. Preference for rooting Spiralia on Platyhelminthes is a long-branch artefact. Most analyses on the 15 unrooted trees showed a preference for the same topology but the support over other solutions was non significant. We conclude that the spiralian phyla emerged in rapid succession resulting in a difficult to resolve radiation. The deep history we infer for Spiralia has wide ranging implications for our interpretation of Cambrian fossils and for the evolution of traits such as biomineralization, segmentation and larvae. Impact Statement Analyses of two independent phylogenomic datasets suggest an explosive radiation at the origin of Spiralia, with implications for understanding the group’s evolutionary history. ### Competing Interest Statement The authors have declared no competing interest.

Abstract. Here, we present a high-quality, chromosome-scale genome assembly for the redlip blenny Ophioblennius macclurei (family Blennidae). The assembly

Habrá un homenaje a Jane Goodall en el que Rebeca Atencia, considerada su sucesora, hablará de su experiencia con la primatóloga

Land plants (embryophytes) are the morphologically most elaborate photosynthetic eukaryotes. The evolutionary origin of many of their key morphogeneti…

Karriereportal

Bioinformatician, Department of Organismal Biology, Uppsala University

There is a long-standing consensus that the animal phyla closest to our own phylum of Chordata are the Echinodermata and Hemichordata. These three phy…

This month's ERGA BioGenome Analysis & Applications Seminar will feature a talk by speaker Pío Sierra about a new tool, pantera, which allows faster identification of Transposable Elements in genome a...