Finding. A long-argued bivalve clade, APPD, is a real order (Anomiida) about 428 million years away from scallops and file shells, and its mitochondria do not speak the usual invertebrate code. Some species still do. Heteranomia frameshifts +1 to dodge in-frame TAG. Anomia, Enigmonia, Placuna, and plicatulids have reassigned TAA to tyrosine, and peptides confirm it. Anyone still translating these mitogenomes with the default table is inventing stop codons. The nucleus, meanwhile, fused its way down from 20 ancestral linkage groups to 6–13 chromosomes.
Why this paper matters
Codon reassignment in mitochondria is one of the organelle’s oldest party tricks. A proteome-confirmed TAA-to-tyrosine table in a newly ranked order is a methods emergency for anyone mining bivalve mtDNA, and a recoding-evolution case for everyone else.
The paper is also a systematics bomb (new order, chromosome fusions, vestigial centromeres). Those support the clade. The mitochondrial-desk payload is the translation table.
What they actually measured
Integrated phylogenomics and morphology; three new genomes; karyotype/centromere architecture; mitochondrial codes across genera; proteomic confirmation of TAA as tyrosine; frameshifting in Heteranomia.
How to read the score
High sixties to low seventies as an mtDNA-code paper. Confidence is high for recoding in the sampled genera, medium for the ordinal revision’s community fate. Score 70.
What to do with it
If you annotate bivalve mitogenomes or study codon reassignment, switch tables for Anomiida. Pull the proteomic TAA-Tyr peptides. Ignore this if you wanted OXPHOS disease. The directional implication is that mitochondrial translation in this order is a living recoding experiment.