Twenty-first century advances in knowledge of the biology of moa (Aves: Dinornithiformes): a new morphological analysis and moa diagnoses revised

Worthy, Trevor H.; Scofield, R. Paul

doi:10.1080/03014223.2012.665060

Cited by 81 publications

(87 citation statements)

References 86 publications

(84 reference statements)

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“…Such great structural differences among moa may relate to the habitats that they occupied. Moa were browsers, consuming herbs and low shrubs (Wood et al, 2008;Worthy and Scofield, 2012). A potential explanation for the large difference in Q i is that Dinornis may have occupied open habitat, whereas other moa foraged in closed forests (Bunce et al, 2009).…”

Section: Moamentioning

confidence: 99%

Blood flow for bone remodelling correlates with locomotion in living and extinct birds

Allan

Cassey

Snelling

et al. 2014

Journal of Experimental Biology

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Nutrient arteries enter limb bones through discrete foramina on the shafts. They are required for bone remodelling in response to mechanical loading and dynamic forces imposed by locomotion. The cross-sectional area of the nutrient foramen of the femur represents an index of blood flow rate to the shaft and thus provides insight into the animal's level of activity. Morphometric data on femoral length, mass and foramen size from 100 extant bird species and eight extinct moa species were analysed allometrically and phylogenetically. The nutrient foramen blood flow index (Q i ) and femur mass (M f ) increase with body mass (M b ). At 1 kg body mass, cursorial species have approximately 2.1 times higher Q i and 1.9 times heavier M f than volant species. The scaling of Q i on M f is independent of the primary mode of locomotion, but the ratio Q i /M f decreases significantly in larger birds, although absolute Q i increases. The overall avian equation for Q i on M b is not significantly different from previous data from mammals, but when differences in blood pressure are accounted for, estimated blood flow to the femur is approximately 1.9 times higher in cursorial birds than in mammals, possibly in relation to bipedalism and quadrupedalism, respectively. Femoral bone blood flow in both endothermic groups is estimated to be 50-100 times higher than in ectothermic reptiles.

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Section: Moamentioning

confidence: 99%

Blood flow for bone remodelling correlates with locomotion in living and extinct birds

Allan

Cassey

Snelling

et al. 2014

Journal of Experimental Biology

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“…All analyses strongly retrieved the kiwi-elephant bird clade/split (Table S9). The 34 taxa (17 palaeognaths and 17 outgroups; Table S4) in the concatenated mitochondrial and nuclear datasets were scored for morphological data using a dataset derived from Worthy and Scofield (17), with additional characters from Johnston (16). Fifteen of the seventeen palaeognath taxa could be scored for morphology (only Apteryx haastii and Tinamus major lacked morphological data), along with three outgroups (Table S4).…”

Section: Testing Sensitivity Of Tree Topology (Mitochondrial Nuclearmentioning

confidence: 99%

Ancient DNA reveals elephant birds and kiwi are sister taxa and clarifies ratite bird evolution

Mitchell

Llamas

Soubrier

et al. 2014

Science

260

314

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The evolution of the ratite birds has been widely attributed to vicariant speciation, driven by the Cretaceous breakup of the supercontinent Gondwana. The early isolation of Africa and Madagascar implies that the ostrich and extinct Madagascan elephant birds (Aepyornithidae) should be the oldest ratite lineages. We sequenced the mitochondrial genomes of two elephant birds and performed phylogenetic analyses, which revealed they are the closest relatives of the New Zealand kiwi, and distant from the basal ratite lineage of ostriches. This unexpected result strongly contradicts continental vicariance and instead supports flighted dispersal in all major ratite lineages. We suggest that convergence towards gigantism and flightlessness was facilitated by early Tertiary expansion into the diurnal herbivory niche following the extinction of the dinosaurs.One Sentence Summary: Ancient DNA reveals massive Madagascan elephant birds and tiny NZ kiwi are closest relatives, and supports flighted origin of ratites. Main Text:Despite extensive studies, the evolutionary history of the giant flightless ratite birds of the southern hemisphere landmasses, and the related flighted tinamous of South America, has remained a major unresolved question. The ratites and tinamous, termed palaeognaths due to their shared 'basal' palate structure, form the sister-taxon to all other living birds (neognaths). The living ratites are one of the few bird groups comprised largely of giant terrestrial herbivores and include: the emu and cassowary in Australia and New Guinea; kiwi in New Zealand; ostriches in Africa; and rhea in South America. In addition, two recently extinct groups included the largest birds known: the moa from New Zealand (1) [up to 2-3 m and 250 kg] and elephant birds from Madagascar [2-3 m height but up to 275 kg] (2, 3). Ratites have been believed to have originated through vicariant speciation driven by the continental breakup of Gondwana on the basis of congruence between the sequence of continental rifting and the presumed order of lineage divergence and distribution of ratites (4,5).New Zealand is the only landmass to have supported two major ratite lineages, the giant herbivorous moa and the chicken-sized, nocturnal, omnivorous kiwi. Morphological phylogenetic analyses initially suggested that these two groups were each other's closest relatives (6, 7), presumably diverging after the isolation of an ancestral form following the separation of New Zealand and Australia in the late Cretaceous ca. 80-60 million years ago (Ma) (8). However, subsequent studies suggest that kiwi are more closely related to the Australasian emu and cassowaries (9, 10), while the closest living relatives of the giant moa are the flighted South American tinamous (11-14). The latter relationship was completely unexpected on morphological grounds, and suggests a more complex evolutionary history than predicted by a model of strict vicariant speciation. By rendering ratites paraphyletic, the relationship between moa and tinamous also strong...

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“…Direct body mass measurements were used for extant ratites, whereas moa body masses were calculated using an algorithm based on available skeletal measurement data. Femoral circumference, an accurate predictor of body mass in large birds, has recently been used to estimate body masses for some moa taxa [19,39]; however, published femoral circumference data are unavailable for moa samples containing identified sexual dimorphs [16,17,20], so a regression equation developed for birds in general (and irrespective of sex) based on femoral length [40], representing another widely used predictor of avian body mass also used in recent moa studies [14,17,39], was used instead. Although the use of a broad-taxon regression to calculate moa body masses could conceivably affect accuracy of estimation if moa deviated consistently in size from taxon-wide trends, different moa species show considerable variation in robust or gracile leg morphology [14,41], suggesting that our estimates are unlikely to be consistently biased, and the high R 2 value for this equation (0.99 [40]) further indicates that our mass estimates are likely to be accurate and so useful for investigating patterns of palaeognath evolution.…”

Section: Materials and Methods (A) Body Mass Datamentioning

confidence: 99%

“…Dinornis body mass estimates vary widely from different Pleistocene and Holocene environments, and so median, minimum, and maximum estimates are used for each species.) rspb.royalsocietypublishing.org Proc R Soc B 280: 20130401 Indeed, whereas species-level taxonomy for most extant ratites and genus-level taxonomy for moa are both well understood, moa species-level taxonomy is notoriously unstable and has been in a state of continuing revision in recent years [14][15][16]19,42,43]. Tinamous are genus-and species-rich, and so we selected two representative genera (Tinamus and Eudromia) for which male and female body mass data are available and which are close to the root of the tinamou clade [47].…”

Section: (B) Phylogeniesmentioning

confidence: 99%

“…Bimodal body size measurement data considered to represent sexually dimorphic populations are available for large temporally/geographically sympatric samples of Euryapteryx curtus and Pachyornis geranoides (¼P. mappini [19]), with females again provisionally identified as the larger sex [20]. RSD has now been confirmed in Euryapteryx, Pachyornis and Emeus through ancient DNA research [16].…”

Section: Introductionmentioning

confidence: 99%

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The evolution of sexual dimorphism in New Zealand giant moa (Dinornis) and other ratites

Olson

Turvey

2013

Proc. R. Soc. B.

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The extinct giant moa Dinornis is one of the most remarkable known examples of reversed sexual size dimorphism (RSD), with males weighing 34-85 kg, but females weighing up to 240 kg. However, there has been little consideration of the evolutionary mechanism that produced this level of dimorphism, and most living palaeognaths also exhibit varying levels of RSD. Using male and female body mass data for extant ratites and tinamous and four extinct moa genera, and tests of phylogenetic dependence (l) of body size evolution among these species, we investigated whether Dinornis was truly unusual with respect to RSD relative to other palaeognaths, which sex was under greater pressure to change in size over evolutionary time, and which candidate hypotheses explaining the presence and variability of RSD in the genus are most plausible. We demonstrate that the extreme level of RSD exhibited by Dinornis represents a straightforward consequence of positive allometric scaling of body size. However, Dinornis females have undergone more evolutionary change than males, and larger females from high-productivity environments are associated with greater differentiation, possibly driven by intraspecific competition and female-biased selection for increased offspring investment.

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Twenty-first century advances in knowledge of the biology of moa (Aves: Dinornithiformes): a new morphological analysis and moa diagnoses revised

Cited by 81 publications

References 86 publications

Blood flow for bone remodelling correlates with locomotion in living and extinct birds

Blood flow for bone remodelling correlates with locomotion in living and extinct birds

Ancient DNA reveals elephant birds and kiwi are sister taxa and clarifies ratite bird evolution

The evolution of sexual dimorphism in New Zealand giant moa (Dinornis) and other ratites

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