Phylogenomic reconstruction of Solenogastres (Mollusca, Aplacophora) informs hypotheses on body size evolution.

Body size is a fundamental characteristic of animals that impacts every aspect of their biology from anatomical complexity to ecology. In Mollusca, Solenogastres has been considered important to understanding the group's early evolution as most morphology-based phylogenetic reconstructions placed it as an early branching molluscan lineage. Under this scenario, molluscs were thought to have evolved from a small, turbellarian-like ancestor and small (i.

Scaphopoda is the sister taxon to Bivalvia: Evidence of ancient incomplete lineage sorting.

The almost simultaneous emergence of major animal phyla during the early Cambrian shaped modern animal biodiversity. Reconstructing evolutionary relationships among such closely spaced branches in the animal tree of life has proven to be a major challenge, hindering understanding of early animal evolution and the fossil record. This is particularly true in the species-rich and highly varied Mollusca where dramatic inconsistency among paleontological, morphological, and molecular evidence has led to a long-standing debate about the group's phylogeny and the nature of dozens of enigmatic fossil taxa.

Genome of the lepidopleurid chiton (Mollusca, Polyplacophora).

Mollusca is the second most species-rich phylum and includes animals as disparate as octopuses, clams, and chitons. Dozens of molluscan genomes are available, but only one representative of the subphylum Aculifera, the sister taxon to all other molluscs, has been sequenced to date, hindering comparative and evolutionary studies. To facilitate evolutionary studies across Mollusca, we sequenced the genome of a second aculiferan mollusc, the lepidopleurid chiton (Bean 1844), using a hybrid approach combining Oxford Nanopore and Illumina reads.