Ratites: Ostriches, Emus, Elephant Birds, and More

One trait that developed time and again in certain bird groups as they diversified and spread around the world after the Flood, was flightlessness. From penguins and the dodo, flightless rails and kiwis, a flightless parrot (kakapo), flightless ducks on the Hawaiian islands and a big flightless owl on Cuba, to giant predators like the South American phorusrhacids, and giant herbivores (probably) like the Australian dromornithids or the widespread Gastornis, many birds have lost the ability to fly while adapting to terrestrial or aquatic habits. This has always been a one-way development, as no flightless birds appear to have managed to reverse the adaptation. There are at least 150 cases of flightlessness developing from flying ancestors (Sayol et al. 2020).

With a few exceptions such as the South American Patagopterygiformes and the aquatic divers of the Hesperornithes, most known flightless birds are from the Cenozoic, so are primarily post-Flood. While some birds are flightless today, and some died out before Noah’s descendants spread over the Earth, human-driven extinction appears to have killed off quite a few others. These were mostly island birds. Humans found them ready and easy prey, overhunting them to extinction, or pests like rats were inadvertently introduced to discover a flightless feast.

Here we will look at the Palaeognathae, an infraclass of birds that includes many of our living flightless birds. When flightless, these birds (ostriches, emus, rheas, kiwis, moas, etc.) are termed ratites. (Only the tinamous are still capable of flight.) It is possible that palaeognaths (usually spelled paleognaths) are comprised of more than one baraminic lineage (created kind), and it is also likely that these baraminic lineages are multi-familial. Flightlessness occurred multiple times, independently, within ratites (Harshman et al. 2008), so possibly multiple times within certain baraminic lineages. This would be difficult to explain if flightlessness was principally due to random mutations. Research suggests, however, that the ‘convergence’ of flightlessness within ratites follows a similar regulatory pathway through accelerated conserved non-exonic elements (Sackton et al. 2019). This suggests a built-in genomic framework that promotes genetic change towards adaptation. (Faux and Field (2017) noted some developmental differences: flightlessness in ostriches was due to peramorphosis, while in emus and cassowaries it was due to paedomorphosis. This fits with an adaptive genomic framework that can creatively solve problems, rather than forcing a single solution.)

Besides flightlessness, gigantism also occurred numerous times independently within ratites (Yonezawa et al. 2017). While gigantism occurred in some early paleognaths, most of the largest sizes developed in the late Cenozoic, suggesting a link to a cooling climate after the Miocene (Crouch and Clarke 2019).

Secular biologists have debated whether dispersal (via flying ancestors) or vicariance (populations separating due to continental breakup) have most influenced the origin of flightless ratites (Grealy et al. 2017; Widrig and Field 2022). For creation models, vicariance is not an option as no birds survived the Flood outside the Ark, while the continents were breaking up. Of course, within a creation model, some Ark ratites could potentially have been flightless and simply dispersed via land bridges or rafting, as did many mammals. (Land bridges and rafting have also been suggested by some secular authors to explain certain biogeographic anomalies with ratites (Van Tuinen et al. 1998).)

The North American and European lithornithids are the oldest known fossil paleognaths, from the Paleocene and Eocene, and appear to have been chicken-sized birds capable of long-distance flying (Phillips et al. 2010; Widrig and Field 2022). That would have been important in early post-Flood dispersal. Interestingly, there is a possible fossil scapula from a lithornithid from Cretaceous New Jersey, though it is not diagnosed with absolute certainty. If it is identified correctly, then a representative of the lithornithids would have been on the Ark. Fossil lithornithids are ‘basal’ paleognaths, and appear morphologically closest to the ostriches (Yonezawa et al. 2017). They are usually considered a sister group to all other paleognaths (Almeida et al. 2022). Fossil eggshell characteristics (e.g. aprismatic layers) support their inclusion within the paleognaths (Grellet-Tinner and Dyke 2005).

Ostriches (Struthionidae) have a rich fossil history going back to Miocene deposits. Struthio (which includes the living ostrich) appeared first throughout Miocene Africa (Leonard et al. 2006), then dispersed into Europe and Asia (Kampouridis et al. 2020; Li et al. 2021). Related ratites (within the Struthioformes) also occupied Africa at the same time, though are primarily known from fossil eggshell presence (Harrison and Msuya 2005). Ostriches continued in Africa in the Pliocene and Pleistocene, to today (Stidham 2004). Ancient DNA analysis and radiocarbon dating on fossil eggshells suggests that ostriches may have survived into the late Pleistocene in India (Blinkhorn et al. 2015; Jain et al. 2017). One species of Struthio is known from the late Pleistocene of China (Buffetaut and Angst 2021). Besides Struthio, however, there was a much larger ostrich: Pachystruthio. This giant ostrich may have stood over 11 feet high, weighing just under 1000 lbs. Fossils have been found in Europe and Asia, from the late Pliocene into the Pleistocene (Zelenkov et al. 2019; Buffetaut and Angst 2021). Larger fossil Struthio were found in Africa, but they were not as large as Pachystruthio; morphological comparisons also show that Struthio femurs tend to be more gracile than the robust femurs of Pachystruthio. Today, the modern ostrich is all that is left, now surviving only in Africa as the last of the Arabian subspecies was seen in the 1960s.

Fossil ‘ostrich-like’ eggshells support the early expansive dispersal of struthionids, but also suggest greater diversity than may be recognized with fossil bones. Fossil eggshells have their own systematic arrangement (ootaxa), and there are a number of morphological features (surface texture, pore size and shape, layer boundary definition, etc.) used to distinguish them (Patnaik et al. 2009). The modern ostrich and the extinct (Holocene) elephant birds (Aepyornis) have eggs with very different pore patterns, so when ‘Aepyornis-like’ eggshell fossils were found in Miocene Africa (and Turkey), it was thought that aepyornids might have had a wider range outside of Madagascar at one time. Studies have shown, however, that the ostrich and aepyornid pore patterns are just two extremes on a spectrum of pore variability that have fluctuated over time within different ostrich lineages (Mikhailov and Zelenkov 2020). Evidence for aepyornids outside Madagascar is therefore lacking, while ostrich diversity expanded.

If true ostriches first show up in the Miocene, where (or what) were they before? A recent study points out morphology (cranial and femoral) suggests that Eocene ‘crane-like’ birds in the Eogruidae and Ergilornithidae are stem Struthioniformes (Mayr and Zelenkov 2021). Those authors also argue that the extinct Palaeotididae should be included in the clade. Within this clade, the earliest recognized bird is the early Eocene wader, Galligeranoides boriensis (Bourdon et al. 2016; Mayr 2019). Many of these fossil birds are known only from their long hindlimbs, but the Eocene European Palaeotis, at least, is known to have been flightless, as was an early Oligocene eogruid (Mayr 2019). Houde and Haubold (1987) described Palaeotis as ostrich-like, but highly primitive and lacking most of the ostrich’s derived traits. The late Paleocene Remiornis of France was flightless and emu- to ostrich-sized (Mayr 2019; Buffetaut and Ploëg 2020). The ostrich’s direct ancestors were likely Eurasian, before moving into and taking hold in Africa.

Malagasy elephant birds (Aepyornithidae) were among the largest of the paleognaths, with some estimates of Aepyornis maximus reaching about 900 pounds (while the New Zealand moas, Dinornis, may have reached 520 pounds, and the living ostrich might reach 300 pounds) (Amadon 1947). Strangely enough, phylogenetic studies show the elephant birds of Madagascar appear to be most closely related to the kiwis of New Zealand, with neither all that close to the ‘basal’ ostriches (Mitchell, et al. 2014). This is an unusual relationship, as the large elephant birds were diurnal herbivores, while the much smaller kiwis are nocturnal omnivores.

There are two recognized genera of elephant birds, Aepyornis and Mullerornis. (The latter is sometimes placed within its own family, the Mullerornithidae.) A third genus, Vorombe, was erected to describe a very large elephant bird (Vorombe titan), but later genetic studies indicated that there was no species-level distinction, and it may have been an example of sexual dimorphism (Hansford and Turvey 2018; Grealy et al. 2023). The ‘crown’ elephant birds appear to have been smaller (under 200 pounds), with gigantism emerging as a derived trait in the absence of large predators in Madagascar (Grealy et al. 2023).

While most of the large ratites have large eggs, elephant bird eggs were extraordinarily large. The elephant birds would not have been able to support their eggs within the pelvic cavity the same way that ostriches and other large extant ratites do, and likely used a similar internal strategy to what the kiwis do (as kiwis also have proportionally larger eggs) (Endo et al. 2012).

‘Aepyornithid-type’ eggshells are known from various locations (Miocene to Pliocene) in Asia and Africa (Harrison and Msuya 2005; Bibi et al. 2006), but as noted above, these likely represent fossil ostrich species with divergent egg pore morphologies. As there are no aepyornithid fossils outside of Madagascar (and those on Madagascar only go back to Pleistocene deposits), their development is entirely speculative. Given their close relationship to kiwis, however, it is entirely possible that elephant birds had a smaller flying ancestor that made it to Madagascar and adapted to that island with flightlessness and gigantism. Use of a land bridge between Africa and Madagascar had been suggested in the past (Masters et al. 2006), but only because the authors were following a vicariance model of ratite evolution.

Kiwis (Apterygidae) were originally considered to be related to the much larger moas, which were also found in New Zealand. When phylogenetic studies showed that they were instead more closely related to the Madagascan elephant birds, that indicated that the kiwis’ ancestral species must have originally flown to New Zealand from Africa or Asia. (For creationists, even rafting would have been a very unlikely means of transport; only very small animals like lizards and frogs managed to survive oceanic rafting to New Zealand.) The earliest fossil kiwis (Propateryx) come from lower Miocene sediments, and were “markedly smaller and possibly volant”, meaning smaller than living kiwis and likely able to fly (Worthy et al. 2013). The kiwi lineage then likely underwent adaptation by increasing in size, becoming flightless (having only vestigial wings), and becoming nocturnal. Genomic adaptations to the visual and olfactory systems that accompanied nocturnality in kiwis have been noted (Le Duc et al. 2015). While New Zealand had no mammalian predators, it did have avian predators like raptors and the now-extinct flightless adzebills. Nocturnality would decrease encounters with most of those.

There are now five living species of kiwis, with a number of cryptic lineages suggested. Rapid diversification during the Pleistocene may have been driven by glaciation (Weir et al. 2016).

Moas (Dinornithiformes) were flightless herbivores found on New Zealand. Some Dinornis females stood around 12 feet tall, weighing 500-600 lbs. (Males were usually much smaller, demonstrating sexual dimorphism (Olson and Turvey 2013).) Other species were smaller, with Anomalopteryx being not much larger than a turkey. Six genera in three families are known from the Pleistocene and Holocene, showing that moas were part of a multi-familial baraminic lineage. (Moas were hunted to extinction after the arrival of humans to New Zealand.) Diversification correlates to exploiting different habitats and diet, whether twigs, coarse leaves, or berries, but was likely driven by tectonic and climatic events (Baker et al. 2005). Moa fossil bones date back to Pliocene strata (Tennyson 2010), with fossil moa tracks known from the Pliocene-early Pleistocene of Otago, South Island (Fleury et al 2023). Eggshell and bone fragments consistent with moas have been found in the Miocene St. Bathans Fauna (Tennyson et al. 2010).

Moas are unique among the palaeognaths in that they did not have even vestigial wings; they were completely wingless. The only remaining element of the forelimb that they retain is the finger-like scapulocoracoid bone (Huynen et al. 2014). The latter authors note that, “Flightlessness and forelimb loss is thought to occur by gradual [diminishment] as a result of changes in expression of a number of select genes,” and that the continued expression of one forelimb-specific gene [tbx5] in moas might suggest a repurposing of the scapulocoracoid bone.

Moas were not related to the New Zealand kiwis (as noted above) (Cooper et al. 1992), but surprisingly were most closely to the living South American tinamous (which are capable of flight, though they prefer scuttling away) (Phillips et al. 2010; Baker et al. 2014). The secular debate between vicariance (due to the rifting of Gondwana) or dispersion of flying ancestors crops up with moas, as the earliest fossils are Miocene but appear to have already been flightless. During the Oligocene (and into the Miocene), much of New Zealand is believed to have been underwater (82%; Allentoft and Rawlence 2012), though some argue that there are too many ‘Gondwanan’ relics among New Zealand biota for inundation to have completely stymied survival during that period (Waters and Craw 2006; Tennyson et al. 2010). The diverse radiation in moas appears to have been within a single moa lineage after the Oligocene marine inundation (Bunce et al. 2009).

For creationists, as noted above, vicariance is not an option—it is just a matter of timing as to when, after the Flood, a tinamou-like ancestor species may have flown in to New Zealand and obtained a foothold. Antarctica may have acted as a land bridge up through the Eocene (Yonezawa et al. 2017), allowing an otherwise South American bird species to move close enough to Australasia for incidental flight to New Zealand to occur.

The tinamous (Tinamidae) currently comprise about 47 species of ground-dwelling birds, with two subfamilies (Bertelli et al. 2014; Bertelli 2017; Almeida et al. 2022). The Tinaminae prefer forest habitat, while the Nothurinae prefer open areas. Fossil tinamous are known from Pleistocene, Pliocene, and Miocene deposits in South America (Chandler 2012; Agnolín 2022). Oddly, they appear to be much more closely related genetically to the New Zealand moas than to the South American rheas (Almeida et al. 2022).

The South American Rheidae includes the living genus Rhea, found back to the Pleistocene, and two Pliocene genera from Argentina: Heterorhea and Hinasuri. The genus Rhea has in the past been split into Rhea and Pterocnemia; the extant species have been synonymized into Rhea, but Pterocnemia is still used for certain fossils, such as ‘P. mesopotamica’ of Miocene Argentina (Noriega et al. 2017; Picasso et al. 2022).

Within the broader Rheiformes, there were also the flightless Diogenornis of Eocene Brazil (Mayr 2019; though sometimes considered a casuariid (Picasso and Mosto 2016)) and Opisthodactylus of Miocene and early Pliocene Argentina (Noriega et al. 2017; Picasso et al. 2022). Unidentified ratite fossils from Argentina were initially suggested by Agnolín (2017) as Paleocene, but are better described as Eocene-Miocene (Picasso et al. 2022). An undetermined ratite inhabited Eocene Seymour Island, Antarctica (Cenizo 2012). Rheiform trackways are known from Miocene deposits in Argentina. The extant genus of rhea appears to have expanded its range throughout southern South America during the Pleistocene.

The Casuariidae includes both cassowaries (Casuarius) and emus (Dromaius). This includes three living cassowaries in northern Australia, New Guinea, and the Moluccas, and one living emu in Australia. A third genus, Emuarius, from Oligo-Miocene Australia (South Australia and Queensland) rounds out the family (Boles 2001; Agnolín 2017). Emus are more cursorial than cassowaries, while cassowaries have a distinctive casque (helmet) on their head. The function of the casque appears to be for heat regulation (Eastick et al. 2019).

Dromaius fossils are known from the Miocene, Pliocene, and Pleistocene (Yates and Worthy 2019). Casuarius fossils are known from the Pliocene and Pleistocene (Naish and Perron 2014). (The latter authors suggest that the extant cassowaries in New Guinea are due to Pleistocene migration from Australia, and may be directly unrelated to earlier fossils in New Guinea.) Phylogenetic analysis determined that Emuarius and Dromaius are sister genera, splitting after they had already split from cassowaries (Worthy et al. 2014). The emus became more cursorial (possibly as Australia developed more open areas through aridification), leaving Emuarius to an ‘intermediate’ state between emus and cassowaries.

So how did the Casuariidae get to Australia? An intriguing relationship was suggested by a phylogenetic analysis by Bourdon et al. (2009), where a clade was formed by the emus, cassowaries, and rheas. This would fit well with the concept of an Eocene trans-Antarctic bridge linking South America (rheas) with Australia (emus and cassowaries). This same bridge would connect tinamous to moas, marsupials in South America and Australia, and aquatic platypuses in South America and Australia. As noted above, the Eocene bird Diogenornis of Brazil is usually placed with the rheas, but some authors consider it a South American casuariid (Picasso and Mosto 2016).

There were probably no flightless ‘ratites’ on the Ark. It is more probable that flight-capable paleognathous birds survived the Flood on the Ark (one or more baraminic kinds), then dispersed within the northern hemisphere to Europe, Asia, and North America. One or two groups in North America then dispersed to South America. Flightlessness developed early in certain birds in Europe and Asia. Asia became the origin of ostrich-like birds, which dispersed into Africa. A flight-capable group dispersed into Madagascar and to New Zealand, developing respectively into moas and kiwis. Tinamous and rheids developed in South America (possibly not from the same direct ancestor). Both groups used the trans-Antarctic bridge, becoming the origin stock for both moas in New Zealand (from tinamous) and emus-cassowaries in Australia (from rheids). Land bridges were probably not necessary for most ratite dispersal (except for true ostriches dispersing back to Asia and into Europe), though would have been necessary for certain non-ratite flightless birds. Rafting has been suggested for ratite dispersal, but given the more recent biostratigraphic and molecular evidence, may not have been necessary.

Possible Post-Flood Biogeography and Diversification of Ratites

(Base Map, CC BY-SA 4.0, Crates; some continents would have been closer together through the Eocene.)

(1, Blue) Flying paleognath ancestors depart from Ark, populations disperse and colonize throughout northern hemisphere, some adapting into flightless birds while others remain volant.
(2, Yellow) Diversification into South America, origin of both tinamous and rheids.

(3, Red) 'Crane-like' paleognaths in Asia diversify into ostrich ancestors and move into Africa.

(4, Violet) Flying paleognaths in Eurasia diversify and disperse into Madagascar (adapting into elephant birds) and New Zealand (adapting into kiwis).

(5, Green) South American ratites populate the trans-Antarctic bridge, dispersing into Australia (adapting into the emus and cassowaries) and New Zealand (adapting into moas).

(6, Orange) True ostriches disperse from Africa back to Asia and into Europe.

Agnolín, F. L. 2017. Unexpected diversity of ratites (Aves, Palaeognathae) in the early Cenozoic of South America: palaeobiogeographical implications. Alcheringa 41: 101-111.

Agnolín, F. L. 2022. New fossil birds from the Miocene of Patagonia, Argentina. Poeyana 513: 1-43.

Allentoft, M. E., and N. J. Rawlence. 2012. Moa’s ark or volant ghosts of Gondwana? Insights from nineteen years of ancient DNA research on the extinct moa (Aves: Dinornithiformes) of New Zealand. Annals of Anatomy–Anatomischer Anzeiger 194(1): 36-51.

Almeida, F. C., et al. 2022. The evolution of tinamous (Palaeognathae: Tinamidae) in light of molecular and combined analyses. Zoological Journal of the Linnean Society 195: 106-124.

Amadon, D. 1947. An estimated weight of the largest known bird. Condor 49(July): 159-164.

Baker, A. J., et al. 2005. Reconstructing the tempo and mode of evolution in an extinct clade of birds with ancient DNA: The giant moas of New Zealand. PNAS 102(23): 8257-8262.

Baker, A. J., et al. 2014. Genomic support for a moa-tinamou clade and adaptive morphological convergence in flightless ratites. Molecular Biology and Evolution 31(7): 1686-1696.

Bertelli, S. 2017. Advances on tinamou phylogeny: An assembled cladistic study of the volant palaeognathous birds. Cladistics 33: 351-374.

Bertelli, S., L. M. Chiappe, and G. Mayr. 2014. Phylogenetic interrelationships of living and extinct Tinamidae, volant palaeognathous birds from the New World. Zoological Journal of the Linnean Society 172(1): 145-184.

Bibi, F., et al. 2006. New fossil ratite (Aves: Palaeognathae) eggshell discoveries from the late Miocene Baynunah Formation of the United Arab Emirates, Arabian Peninsula. Palaeontologia Electronica 9(1; 2A): 1-13.

Blinkhorn, J., H. Achyuthan, M. D. Petraglia. 2015. Ostrich expansion into India during the late Pleistocene: Implications for continental dispersal corridors. Palaeogeography, Palaeoclimatology, Palaeoecology 417: 80-90.

Boles, W. 2001. A new emu (Dromaiinae) from the late Oligocene Etadunna Formation. Emu 101: 317-321.

Bourdon, E., A. De Ricqles, and J. Cubo. 2009. A new Transantarctic relationship: Morphological evidence for a Rheidae–Dromaiidae–Casuariidae clade (Aves, Palaeognathae, Ratitae). Zoological Journal of the Linnean Society 156: 641-663.

Bourdon, E., C. Mourer-Chauviré, and Y. Laurent. 2016. Early Eocene birds from La Borie, southern France. Acta Palaeontologica Polonica 61(1): 175-190.

Buffetaut, E., and G. de Ploëg. 2020. Giant birds from the uppermost Paleocene of Rivecourt (Oise, northern France). Boletim do Centro Português de Geo-História e Pré- História 2(1): 29-33.

Buffetaut, E., and D. Angst. 2021. A giant ostrich from the lower Pleistocene Nihewan Formation of North China, with a review of the fossil ostriches of China. Diversity 13(47): 1-12.

Bunce, et al. 2009. The evolutionary history of the extinct ratite moa and New Zealand Neogene paleogeography. PNAS 106(49): 20646-20651.

Cenizo, M. M. 2012. Review of the putative Phorurhacidae from the Cretaceous and Paleogene of Antarctica: New records of ratites and pelagornithid birds. Polish Polar Research 33(3): 239-258.

Chandler, R. M. 2012. A new species of tinamou (Aves: Tinamiformes, Tinamidae) from the early-middle Miocene of Argentina. PalArch’s Journal of Vertebrate Palaeontology 9(2): 1-8.

Cooper, A., et al. 1992. Independent origins of New Zealand moas and kiwis. PNAS 89: 8741-8744.

Crouch, N. M. A., and J. A. Clarke. 2019. Body size evolution in palaeognath birds is consistent with Neogene cooling-linked gigantism. Palaeogeography, Palaeoclimatology, Palaeoecology 532: 109224.

Eastick, D. L., et al. 2019. Cassowary casques act as thermal windows. Scientific Reports 9(1966): 1-7.

Endo, H., et al. 2012. Coxa morphologically adapted to large egg in aepyornithid species compared with various palaeognaths. Anatomia Histologia Embryologia 41: 31-40.

Faux, C., and D. J. Field. 2017. Distinct developmental pathways underlie independent losses of flight in ratites. Biology Letters 13: 20170234.

Fleury, K., et al. 2023. The moa footprints from the Pliocene-early Pleistocene of Kyeburn, Otago, New Zealand. Journal of the Royal Society of New Zealand https://doi.org/10.1080/03036758.2023.2264789.

Grealy, A., et al. 2017. Eggshell palaeogenomics: Palaeognath evolutionary history revealed through ancient nuclear and mitochondrial DNA from Madagascan elephant bird (Aepyornis sp.) eggshell. Molecular Phylogenetics and Evolution 109: 151-163.

Grealy, A., et al. 2023. Molecular exploration of fossil eggshell uncovers hidden lineage of giant extinct bird. Nature Communications 14(914): 1-14.

Grellet-Tinner, G., and G. J. Dyke. 2005. The eggshell of the Eocene bird Lithornis. Acta Palaeontologica Polonica 50(4): 831-835.

Hansford, J. P., and S. T. Turvey. 2018. Unexpected diversity within the extinct elephant birds (Aves: Aepyornithidae) and a new identity for the world’s largest bird. Royal Society Open Science 5: 181295.

Harrison, T., and C. P. Msuya. 2005. Fossil struthionid eggshells from Laetoli, Tanzania: Taxonomic and biostratigraphic significance. Journal of African Earth Sciences 41: 303-315.

Harshman, J., et al. 2008. Phylogenomic evidence for multiple losses of flight in ratite birds. PNAS 106(36): 13462-13467.

Houde, P., and H. Haubold. 1987. Palaeotis weigelti restudied: A small middle Eocene ostrich (Aves: Struthioniformes). Palaeovertebrata 17(2): 27-42.

Huynen, L., et al. 2014. Reconstruction and in vivo analysis of the extinct tbx5 gene from ancient wingless moa (Aves: Dinornithiformes). BMC Evolutionary Biology 14(75): 1-8.

Jain, S., et al. 2017. Ancient DNA reveals late Pleistocene existence of ostriches in Indian sub-continent. PLoS ONE 12(3): e0164823.

Kampouridis, P., et al. 2020. First description of an ostrich from the late Miocene of Kerassia (Euboea, Greece): Remarks on its cervical anatomy. Historical Biology 33(10): 2228-2235.

Le Duc, D., et al. 2015. Kiwi genome provides insights into evolution of a nocturnal lifestyle. Genome Biology 16(147): 1-15.

Leonard, L. M., G. J. Dyke, and C. A. Walker. 2006. New specimens of a fossil ostrich from the Miocene of Kenya. Journal of African Earth Sciences 45: 391-394.

Li, Z.-H., et al. 2021. Exceptional preservation of an extinct ostrich from the late Miocene Linxia Basin of China. Vertebrata PalAsiatica 59(3): 229-244.

Masters, J. C., M. J. de Wit, and R. J. Asher. 2006. Reconciling the origins of Africa, India and Madagascar with vertebrate dispersal scenarios. Folia Primatologica 77: 399-418.

Mayr, G. 2019. Hindlimb morphology of Palaeotis suggests palaeognathous affinities of the Geranoididae and other “crane-like” birds from the Eocene of the Northern Hemisphere. Acta Palaeontologica Polonica 64(4): 669-678.

Mayr, G., and N. Zelenkov. 2021. Extinct crane-like birds (Eogruidae and Ergilornithidae) from the Cenozoic of Central Asia are indeed ostrich precursors. Ornithology 138: 1-15.

Mikhailov, K. E., and N. Zelenkov. 2020. The late Cenozoic history of the ostriches (Aves: Struthionidae), as revealed by fossil eggshell and bone remains. Earth-Science Reviews 208: 103270.

Mitchell, K. J., et al. 2014. Ancient DNA reveals elephant birds and kiwis are sister taxa and clarifies ratite bird evolution. Science 344(6186): 898-900.

Naish, D., and R. Perron. 2014. Structure and function of the cassowary’s casque and its implications for cassowary history, biology and evolution. Historical Biology 28(4): 507-518.

Noriega, J. I., et al. 2017. A new species of Opisthodactylus Ameghino, 1891 (Aves, Rheidae), from the late Miocene of northwestern Argentina, with implications for the paleobiogeography and phylogeny of rheas. Journal of Vertebrate Paleontology http://dx.doi.org/10.1080/02724634.2017.1278005

Olson, V. A., and S. T. Turvey. 2013. The evolution of sexual dimorphism in New Zealand giant moa (Dinornis) and other ratites. Proceedings of the Royal Society B 280: 20130401.

Patnaik, R., et al. 2009. Ostrich-like eggshells from a 10.1 million-yr-old Miocene ape locality, Haritalyangar, Himachal Pradesh, India. Current Science 96(11): 1485-1495.

Phillips, M. J., et al. 2010. Tinamous and moa flock together: Mitochondrial genome sequence analysis reveals independent losses of flight among ratites. Systematic Biology 59(1): 90-107.

Picasso, M. B. J., and M. C. Mosto. 2016. New insights about Hinasuri nehuensis (Aves, Rheidae, Palaeognathae) from the early Pliocene of Argentina. Alcheringa 40(2): 244-250.

Picasso, M. B. J., C. A. Hospitaleche, and M. C. Mosto. 2022. An overview and update of South American and Antarctic fossil rheidae and putative ratitae (Aves, Palaeognathae). Journal of South American Earth Sciences 115: 103731.

Sackton, T. B., et al. 2019. Convergent regulatory evolution and loss of flight in paleognathous birds. Science 364: 74-78.

Sayol, F., et al. 2020. Anthropogenic extinctions conceal widespread evolution of flightlessness in birds. Science Advances 6: eabb6095.

Stidham, T. A. 2004. Extinct ostrich eggshell (Aves: Struthionidae) from the Pliocene Chiwondo Beds, Malawi: Implications for the potential biostratigraphic correlation of African Neogene deposits. Journal of Human Evolution 46: 489-496.

Tennyson, A. J. D. 2010. The origin and history of New Zealand’s terrestrial vertebrates. New Zealand Journal of Ecology 34(1): 6-27.

Tennyson, A. J. D., et al. 2010. Moa’s ark: Miocene fossils reveal the great antiquity of moa (Aves: Dinornithiformes) in Zealandia. Records of the Australian Museum 62: 105-114.

Van Tuinen, M., C. G. Sibley, and S. B. Hedges. 1998. Phylogeny and biogeography of ratite birds inferred from DNA sequences of the mitochondrial ribosomal genes. Molecular Biology and Evolution 15(4): 370-376.

Waters, J. M., and D. Craw. 2006. Goodbye Gondwana? New Zealand biogeography, geology, and the problem of circularity. Systematic Biology 55(2): 351-356. Weir, J. T., et al. 2016. Explosive ice age diversification of kiwi. PNAS 113(38): E5580-5587.

Widrig, K., and D. J. Field. 2022. The evolution and fossil record of palaeognathous birds (Nornithes: Palaeognathae). Diversity 14(105): 1-69.

Worthy, T. H., et al. 2013. Miocene fossils show that kiwi (Apteryx, Apterygidae) are probably not phyletic dwarves. in: Göhlich, U. B., and A. Kroh (eds.), Paleornithological Research 2013, Verlag Naturhistorisches Museum Wien, 63-80.

Worthy, T. H., S. J. Hand, and M. Archer. 2014. Phylogenetic relationships of the Australian Oligo-Miocene ratite Emuarius gidju Casuariidae. Integrative Zoology 9: 148-166.

Yates, A. M., and T. H. Worthy. 2019. A diminutive species of emu (Casuariidae: Dromaiinae) from the late Miocene of the Northern Territory, Australia. Journal of Vertebrate Paleontology 39(4): e1665057.

Yonezawa, T., et al. 2017. Phylogenomics and morphology of extinct paleognaths reveal the origin and evolution of the ratites. Current Biology 27: 68-77.

Zelenkov, N. V., et al. 2019. A giant early Pleistocene bird from eastern Europe: Unexpected component of terrestrial faunas at the time of early Homo arrival. Journal of Vertebrate Paleontology 39(2), https://doi.org/10.1080/02724634.2019.1605521.

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zoocreation

Ratites

Palaeognathous birds after the flood

Chad Arment (2024)

Lithornithidae

Ostriches

Elephant Birds

kiwis

Moas

Tinamous

Rheas

Cassowaries and Emus

summary

References

2021-2024

zoocreation