Palaeognaths, the sister group of all other living birds (neognaths), were
once considered to be vicariant relics from the breakup of the Gondwanan
supercontinent. However, recent molecular studies instead argue for
dispersal of volant ancestors across marine barriers. Resolving this
debate hinges upon accurately reconstructing their evolutionary
relationships and dating their divergences, which often relies on
phylogenetic information from extinct relatives and nuclear genomes.
Mitogenomes from the extinct elephant birds of Madagascar have helped
inform the palaeognath phylogeny; however, nuclear information has
remained unavailable. Here, we use ancient DNA (aDNA) extracted from
fossil eggshell, together with target enrichment and next-generation
sequencing techniques, to reconstruct an additional new mitogenome from
Aepyornis sp. with 33.5X coverage. We also recover the first elephant bird
nuclear aDNA, represented by 12,500 bp of exonic information. While we
confirm that elephant birds are sister taxa to the kiwi, our data suggests
that, like neognaths, palaeognaths underwent an explosive radiation
between 69 and 52 Ma—well after the break-up of Gondwana, and more rapidly
than previously estimated from mitochondrial data alone. These results
further support the idea that ratites primarily diversified immediately
following the Cretaceous-Palaeogene mass extinction and convergently
evolved flightlessness. Our study reinforces the importance of including
information from the nuclear genome of extinct taxa for recovering deep
evolutionary relationships. Furthermore, with approximately 3% endogenous
aDNA retrieved, avian eggshell can be a valuable substrate for recovering
high quality aDNA. We suggest that elephant bird whole genome recovery is
ultimately achievable, and will provide future insights into the evolution
these birds. RaxML_inputsInput phylip files (.phy) and partition files (_part.txt) used for maximum likelihood tree generation in RaxML for various data sets (mt=mitochondrial, nuc=nuclear, ry=ry-coded, m3=mitochondrial third codon positions, loops=mitochondrial rRNA loops). Note that RY coded bases are given by a 0 (R) or 1 (Y).MrBayes_inputsInput nexus files (.nex) used for Bayesian phylogenetic inference for various datasets (mt=mitochondrial, nuc=nuclear, nt=standard coded (nucleotide), ry=ry-coded, m3=mitochondrial third codon positions, loops=mitochondrial rRNA loops)Nuclear_sequence_alignmentsNon-partitioned multiple sequence alignments for various nuclear loci in FASTA format (.fasta).MCMCTree_inputsInputs in phylip format (.phy) for molecular dating analysis conducted in MCMCTree for several datasets (mt=mitochondrial, nuc=nuclear, nt=standard coded (nucleotide), ry=ry-coded, m3=mitochondrial third codon positions). Note that RY-coded data are represented by R and Y. Tree topologies (.trees) used as input are shown: for mitochondrial and combined mitochondrial/nuclear datasets, two topologies were tested, one in which moa/tinamous are sister to the remaining notopalaeognathae, and one where rheas are sister to the remaining notopalaeognathae. For the nuclear dataset, the topology derived from phylogenetic inference on the nuclear data alone was used. MCMCTree control files (.ctl) are not shown as parameters used are described in text.FASTQTotal shotgun NGS (combined Ion Torrent Proton, Ion Torrent PGM, and MiSeq data as well as enriched and non-enriched libraries) reads (trimmed, quality filtered and unfiltered) in FASTQ format (.fastq).