Extreme reversed sexual size dimorphism in the extinct New Zealand moa Dinornis

Abstract

The ratite moa (Aves; Dinornithiformes) were massive graviportal browsers weighing up to 250 kg (ref. 1) that dominated the New Zealand biota until their extinction approximately 500 yr ago. Despite an extensive Quaternary fossil record, moa taxonomy remains problematic and currently 11 species are recognized. Three Dinornis species were found throughout New Zealand and differed markedly in size (1-2 m height at back) and mass (from approximately 34 to 242 kg). Surprisingly, ancient mitochondrial DNA sequences show that the three species were genetically indistinguishable within each island, but formed separate North and South Island clades. Here we show, using the first sex-linked nuclear sequences from an extinct species, that on each island the three morphological forms actually represent just one species, whose size varied markedly according to sex and habitat. The largest females in this example of extreme reversed sexual size dimorphism were about 280% the weight and 150% the height of the largest males, which is unprecedented among birds and terrestrial mammals. The combination of molecular and palaeontological data highlights the difficulties of analysing extinct groups, even those with detailed fossil records.

A multi-gene phylogeny of aquiline eagles (Aves: Accipitriformes) reveals extensive paraphyly at the genus level

“…However, since Holdaway's (1994) phylogeny did not recover monophyly of Aquilini, the Harpagornis-Aquila relationship also seems doubtful and molecular verification would be desirable. Using ancient DNA, this might be possible given that extensive molecular sequences have been obtained from various sub-fossil moa species of approximately the same age (Bunce et al, 2003;Huynen et al, 2003).…”

Ancient DNA microsatellite analyses of the extinct New Zealand giant moa (Dinornis robustus) identify relatives within a single fossil site

“…As is the case for most extinct taxa, little is known about their biology except some insights into their feeding habits, gained from their gut contents and genetic and morphological analyses of coprolites (e.g., Burrows et al, 1981;Burrows, 1989;Wood et al, 2008Wood et al, , 2013. It has also been demonstrated that moa displayed reverse sexual dimorphism with the females being up to 280% heavier than the males (Bunce et al, 2003;Huynen et al, 2003). Moreover, Allentoft et al (2010) demonstrated by a molecular sexing technique that there was an overall 5:1 excess of females among 267 individuals sampled in North Canterbury.…”

“…The DNA was then isolated and purified using Qiagen (Valencia, CA, USA) silica spin columns. A mtDNA control region sequence of 340 bp (excluding primers) was amplified from 87 individuals using two sets of overlapping primers (Bunce et al, 2003). The associated GenBank accession numbers for the individual mtDNA sequences are presented in Allentoft et al (2014).…”

“…This data set included both mitochondrial DNA (mtDNA) sequences and six genotyped microsatellite loci in 74 radiocarbon-dated individuals of D. robustus, excavated from four sites within a 10 km radius in North Canterbury, South Island (Figure 1), and covering~4200 years of the mid-to-late Holocene. D. robustus was the largest of the moa species with females weighing up to 250 kg (Worthy and Holdaway, 2002;Bunce et al, 2003;Brassey et al, 2013). We employed a range of methods to explore the genetic relatedness among the 74 individuals.…”

Evaluating bacterial pathogen DNA preservation in museum osteological collections

“…(5) We can reject the possibility of failed extraction on the grounds that (i) the technique allows the recovery of host DNA from the samples, (ii) DNA sequences presumably derived from environmental bacteria are recovered from the samples and (iii) because this extraction technique, or a related version, has been used in a wide variety of published studies, including samples with marginal survival of bacterial, fungal and vertebrate DNA (Baron et al 1996;Barnes et al 2002;Bunce et al 2004;Shapiro et al 2004;Willerslev et al 2004).…”