Early Cretaceous Longicrusavis houi under DGS

A complete and articulated,
except for a skull suspiciously emerging from/near the cloaca, Early Cretaceous ornithuromorph bird, Longicrusavis houi (O’Connor, Gao and Chiappe 2010; PKUP V1069), gets the DGS treatment today. That involves segregating the bones by coloring them, then rearranging them to an in vivo pose. This is done without seeing the specimen firsthand. You can see what little the authors saw in figure 1.

Figure 1. Skull of Longicrusavis houi in situ, as originally traced and colorized using the DGS method. Below is a reconstruction based on the colored bones. The palate was not reconstructed, but palatal bones are colored.

Figure 1. Skull of Longicrusavis houi in situ, as originally traced and colorized using the DGS method. Below is a reconstruction based on the colored bones. The palate was not reconstructed, but palatal bones are colored. Quite a bit more data is gleaned without having seen the fossil firsthand here. The occiput is well exposed here. Possible squamosal/quadratojugal contact here. The lacrimal was displaced to the dorsal frontal. The caudals intersect the skull and push the jugal (cyan) dorsally.

After analysis,
Longicrusavis nests in the large reptile tree (LRT, 1027 taxa) at the base of the Yanornis + Changzuiornis clade and these are sisters to Apsaravis + Ichthyornis and Gansus + Hesperornis among the basalmost neognaths. The O’Connor team recovered a similar nesting with a different list of taxa.

Figure 2. It's always valuable to see what the taxon looks like with scale bars. This is a tiny specimen, but rather completely known.

Figure 2. It’s always valuable to see what the taxon looks like with scale bars. This is a tiny specimen, but rather completely known. If you have a typical 72 dpi screen, the images is 1.5x life size.

O’Connor et al. report,
“There are no teeth preserved in PKUP V1069, though alveoli do appear to be present in the premaxilla and maxilla.” I see tiny teeth (Fig. 1). Phylogenetic bracketing indicates it could go either way as derived members of this clade redevelop teeth. The jugal, lacrimal, quadratojugal and several other bones were also overlooked by those who had firsthand access. We’ll see as time goes by and better data comes in.

References
O’Connor JK, Gao K-Q and Chiappe LM 2010. A new ornithuromorph (Aves: Ornithothoraces) bird from the Jehol Group indicative of higher-level diversity. Journal of Vertebrate Paleontology 30(2):311–321.

PKUP, Peking University Paleontological Collection, Beijing, China

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Patagopteryx: it’s a hen-sized ostrich sister in the LRT

Patagopteryx deferrariisi (Late Cretaceous, 80mya; Alvarenga and Bonaparte 1992, Chiappe 1996, Chiappe 2002, MACN-N-03, 10, 11, 14 and others) was a hen-sized bird originally considered a ratite, but later (Chiappe 1996) nested it between Enantiornithes and Hesperonis. Back then Patagopteryx was one of only a few Cretaceous birds known. Here, with more included taxa, Patagopteryx nests with Struthio, the ostrich, back among the ratites.

FIgure 1. Patagopteryx compared to Struthio to scale and scaled to a similar shoulder height.

FIgure 1. Patagopteryx compared to Struthio to scale and scaled to a similar shoulder height. This Late Cretaceous taxon retained four toes and a robust tail.

Four toes are present.
As in Casaurius pedal ungual 2 is elongate. The pubis tip bends ventrally, like a boot. The anterior skull is unknown but otherwise is similar to Struthio.

Figure 2. Patagopteryx skull from Chiappe 2002 with color restoration.

Figure 2. Patagopteryx skull from Chiappe 2002 with color restoration show the skull to be very ostrich like. Note the tiny squamosal barely overlapping the quadrate, smaller than in Struthio.

Aepyornis, the elephant bird, moves over the the tinamous with this taxon addition.

Figure 3. Struthio skull with a long maxilla.

Figure 3. Struthio skull with a long maxilla.

References
Alvarenga and Bonaparte 1992.
 A new flightless land bird from the Cretaceous of Patagonia; pp. 51–64 in K. E. Campbell (ed.), Papers in Avian Paleontology, Honoring Pierce Brodkorb. Natural History Museum of Los Angeles County, Science Series 36.
Chiappe LM 1996. Early avian evolution in the southern hemisphere: Fossil record of birds in the Mesozoic of Gondwana. Memoirs of the Queensland Museum 39:533–556.
Chiappe LM 2002. Osteology of the flightless Patagopteryx deferrariisi from the late Cretaceous of Patagonia (Argentina) pp.281–316 in Mesozoic Birds, Above the Heads of Dinosaurs, Chapter: 13, Editors: Chiappe LM and Witmer LM, University of California Press.

http://www.reptileevolution.com/struthio.htm

The origin of hummingbirds

Hummingbirds are the tiniest of living birds.
They are famous for hovering with wings beating so rapidly they essentially blur from view. Today hummingbirds live only in the New World.

Prum et al. 2015
based on DNA, nested hummingbirds with swifts and these nested with the nocturnal nightjars. That is the traditional nesting.

In the LRT 2015
based on morphology, hummingbirds nest with the extinct Eocypselus (Fig. 4, 50 mya) and the sea gull, Chroicocephalus (Figs. 1, 3; extant). Mayr 2004 reported on an Old World hummingbird, Eurotrochilus inexpectatus (Fig. 4; 30 mya), from the early Oligocene.

Elsewhere on the cladogram,
swifts nest with owls in the large reptile tree (LRT, 1129 taxa).

Figure 1. A sea gull hovering. Many birds can do this for short periods, but sea gulls are phylogenetic sisters to hummingbirds, so this is where it all began for hummers.

Figure 1. A sea gull hovering. Many birds can do this for short periods, but sea gulls are phylogenetic sisters to hummingbirds, so this is where it all began for hummers.

To be fair,
swifts also hover. And here is a sample of that on YouTube. https://www.youtube.com/watch?v=9u8YuBGQWb0
It should be noted that swifts do not feed while hovering. They speed through the air snatching insects in flight. On the other hand, gulls do hover, and here is another image of that (Fig. 2). Gulls appear to hover only in a breeze, which is often present at shorelines. Thus gulls represent the awkward origin of hummingbird hovering, which improved with faster wingbeats. a deeper sternum and a smaller size.

Figure 2. The smallest gull, Hydrocoloeus_minutus, hovering while feeding.

Figure 2. The smallest gull, Hydrocoloeus_minutus, hovering while feeding.

Fossils tell us
that hummingbird-sized specimens, like Eocypselus (Figs. 3, 4), lived 50 mya and probably originated much earlier. One-sixth the size of the small gull, Hydrocoloeus (Figs. 2, 3), Eocypselus had a relatively short, small beak and shorter legs, though still longer than the wings.

Figure 2. Chroicocephalus, the smaller Hydrocoloeus, the much smaller Eocypselus and the ruby-throated hummingbird, Archilochus to scale.

Figure 3. Chroicocephalus, the smaller Hydrocoloeus (the smallest living gull), the much smaller Eocypselus and the ruby-throated hummingbird, Archilochus to scale.

Of course, small size is key to hummingbird evolution.
At this point, I’m not aware of any gulls smaller than Hydrocoloeus, whether extant or in the fossil record. I would like to see a skeleton of Hydrocoloeus to see if it had a larger sternum relative to the 1.25x larger Chroicocephalus. I also wonder if it has a faster wingbeat when hovering based on its smaller size.

Figure 3. Eocypselus from 50 mya, Eurotrochilus, from 30 mya and Archilochus, the extant ruby-throated hummingbird to scale.

Figure 4. Eocypselus from 50 mya, Eurotrochilus, from 30 mya and Archilochus, the extant ruby-throated hummingbird to scale.

The fossil Eutrochilus
(Fig. 4, Mayr 2004) bridges the time gap between Eocypselus and extant hummingbirds and would appear to be a complete and fully realized hummingbird itself, living some 30 mya, while originating much earlier. Eocypselus (Fig. was not much different in size or morphology.

Old World vs. New World
So, based on Eutrochilus, hummingbirds used to be in Europe. Now they are restricted to the New World. Why? There is a long list of hummingbird eaters online here. Something killed European hummingbirds in the Old World… maybe microbes?

Vultures had a similar split.
Today we have New World vultures (like Coragyps, derived from petrels) and Old World vultures (like Torgos, derived from falcons) in the LRT. The odd exception to this hemispherical split is the dodo, Raphus, and its kin, all New World flightless vultures isolated on islands in the Old World. Then there’s a report of an Old World vulture in Miocene Nebraska (Zhang et al. 2012). Really, what’s to stop them? And what killed Old World vultures in the New World? So again, there’s another mystery in need of a good explanation.

References
Mayr G 2004. Old World fossil record of modern-type hummingbirds. Science 304:861–864,
Ksepka DT, Clarke JA, Nesbitt SJ, Kulp FB and Grande L. 2013. Fossil evidence of wing shape in a stem relative of swifts and hummingbirds (Aves, Pan-Apodiformes). Proceedings of the Royal Society B: Biological Sciences 280 (1761): 20130580. doi:10.1098/rspb.2013.0580. Supplementary materials here.
McGuire JA et al. (7 coauthors) 2014. Molecular Phylogenetics and the Diversification of Hummingbirds. Current Biology, 2014; DOI: 10.1016/j.cub.2014.03.016
Zhang Z, Feduccia A and James HF 2012. A Late Miocene Accipitrid (Aves: Accipitriformes) from Nebraska and Its Implications for the Divergence of Old World Vultures. PLoS ONE7(11): e48842. https://doi.org/10.1371/journal.pone.0048842

https://wordpress.com/post/pterosaurheresies.wordpress.com/10805
https://www.livescience.com/44593-first-hummingbird-evolutionary-tree.html

Molecules vs. morphology in bird phylogeny: Prum et al. 2015 part 3

Earlier and the day before we looked at basal euornithine taxa in two cladograms: one recovered from DNA analysis (Prum et al. 2015), and one from morphology (the large reptile tree or LRT, 1026 taxa). Today we’ll look at a few more Prum et al. clades.

Prum et al. clade 5: Gruiformes
These are the rails and cranes and kin: sun grebes (Heliornis), fluff tails (Sarothrura), water rails (Rallus), ocellated crakes (Micropygia), swamp hens (Porphyrio) all in one clade. In the other clade are the shorter trumpeters (Psophia) and limpkins (Aramus), and the taller crowned cranes (Balearica) and cranes (Grus).

In the LRT
only three of the last four are presently included. Psophia nests with roadrunners and cuckoos, but close to Crex, another type of rail, all derived from basal neognaths including the birds of prey clade. Aramus nests at the base of cranes, like Grus, but also terns, sea gulls, hummingbirds, penguins, pigeons and kingfishers, which is in itself quite a mixed bag of taxa—all with a long straight bill, which is not a unique trait among neognaths.

Prum et al. clade 6: Aequorlitornithes
According to Prum et al. “The Aequorlitornithes is a novel, comprehensive clade of waterbirds, including all shorebirds, diving birds, and wading birds. Within this group, the flamingos and grebes are the sister group to shorebirds, and the sunbittern and tropicbirds are the sister group to the wading and diving birds.” This is such a big clade with 18 taxa nesting distinct from 26 others that it needs to be dissected a bit more. Like so:

Aequorlitornithes clade a1: flamingos (Phoenicopterus) and grebes (Rollandia).

In the LRT: flamingos nest with the birds of prey, like the Cariama. Grebes have not been tested, but they look a great deal like loons. In any case, yesterday we looked at the untenable match between grebes and flamingos.

Aequorlitornithes clade a2: thick-knees (Burhinus), plovers and kildeers (Charadrius), oystercatchers (Haematopus), avocets (Recurvirostra).

In the LRT: none of these taxa have been tested at present.

Aequorlitornithes clade a3: plains wanderers (Pedionomus), lily trodders (Jacana), painted snipes (Rostratula), godwits (Limosa), turnstones (Arenaria), waders (Tringa).

In the LRT: none of these taxa have been tested at present.

Aequorlitornithes clade a4: buttonquails (Turnix),  pratincoles (Glareola), murres or guillemots (Uria), sea gulls (Chrococephalus), terns (Sterna) and skimmers (Rhynchops)

In the LRT: murres nest with penguins from clade b1 (see below). Sea gulls nest with hummingbirds (we’ll look at this in more detail tomorrow) and these were sisters to storks. Basically sea gulls were short-legged neotonous storks. Hummingbirds were descendants of Eocypselus, both were tiny neotonous sea gulls with an ancient lineage.

Aequorlitornithes clade b1: sunbitterns (Eurypyga), tropicbirds (Phaethon), loons (Gavia), penguins (Spheniscus).

Figure 1. The tropic bird (genus: Phaethon) in vivo.

Figure 1. The tropic bird (genus: Phaethon) in vivo. At sunset, in silhouette, some people seeing this bird with such long slender tail feathers thought it was a basal pterosaur. 

In the LRT: sunbitterns nest with similar wading storks from clade b3 (below). Loons nest with terns from clade a4 (above). Penguins nest with murres in clade a4, but a node or two apart form loons and terns. Tropicbirds, like Phaethon (Figs. 1,2), nest with barbets and toucans in the LRT.

Figure 2. The skull of the tropic bird, Phaethon rubricauda, most closely related to the barbets in the LRT.

Figure 2. The skull of the tropic bird, Phaethon rubricauda, most closely related to the barbets in the LRT. Note the posteriorly drooping maxilla, a key trait in this clade that also includes hornbills and toucans. 

Aequorlitornithes clade b2: petrels: albatrosses (Phoebastria), storm petrels (Oceanites , Pelagodroma and Oceanodroma,) fulmars (Fulmarus), shearwaters (Puffinus), petrels (Pterodroma), and diving petrels (Pelecanoides).

In the LRT: only one tube nose, Macronectes, has so far been tested. The presence of a tube nose on the rostrum of all these taxa makes this a probable monophyletic clade.

Aequorlitornithes clade b3: storks (Ciconia) maribou storks (Leptoptilos), frigate birds (Fregata), gannets (Morus), darters or snake birds (Anhinga) cormorants (Phalcrocorax), ibises (Theristicus), tiger heron (Tigrisoma), blue herons (Ardea), bitterns (Ixobrychu), hamerkops (Scopus), shoebills (Balaeniceps) and pelicans (Pelecanus).

In the LRT: hamerkops, shoebills and pelicans also nest together. Storks nest apart from herons and also apart from hamerkops and kin. The ibises nest at the base of spoonbills and ducks, sisters to hornbills and toucans. The rest have not yet been tested.

 

 

 

 

 

Palaelodus: transitional between flamingos and grebes?

A short break from our Prum et al. 2015 series
as we take a peek at the origin of flamingos and other basal neognath birds, which we’ll look at in greater depth tomorrow in part 3.

Traditionally
flamingos, like Phoenicopterus (Fig. 1), have been difficult to nest in bird cladograms. Flamingos seem to stand alone. Bird expert Gerald Mayr 2004 quoted Sibley & Ahlquist (1990), who wrote flamingos are “among the ‘most controversial and long-standing problems’” in phylogenetic analysis.

Bird expert
Cracraft (1981) made a luke-warm suggestion for stork affinities. Other bird experts, Olson and Feduccia (1980) liked stilts and avocets as relatives. They also suggested that flamingo-like Palaelodus (Figs. 2, 3) ‘may have occupied a more duck-like swimming niche than do typical flamingos’, The Galloanseres (chickens + ducks invalid clade) was considered, perhaps based on the long-legged duck Presbyornis.

Using molecules,
Prum 2015 and others before them nested the flamingo, Phoenicopterus, with the flightless grebe, Rollandia (Fig. 1). And now (hopefully) you see what I mean when I say, DNA does not recover testable or valid relations over long phylogenetic distances.

Figure 1. The flamingo, Phoenicopterus, compared to the grebe, Rollandia. DNA says these two are more closely related than any other tested taxa. The LRT reports they are not related.

Figure 1. The flamingo, Phoenicopterus, compared to the grebe, Rollandia. DNA says these two are more closely related than any other tested taxa. The LRT reports they are not related.

Using morphology
the large reptile tree, (LRT, 1026 taxa) nests the flamingo with the similarly proportioned, hook-beaked seriema, Cariama sisters to the terrestrial birds of prey, represented today by Sagittarius, the secretary bird. Here (Fig. 2), based on a long list of shared traits, it is possible to see how flamingos could gradually arise from seriemas.

Figure 2. Which taxa share more traits? Phoenicopterus, the flamingo nests with Cariama, the seriema in the LRT, but with Gavia in the Prum et al. DNA study. Gavia nests with Thalasseus, the tern in the LRT.

Figure 2. Which taxa share more traits? Phoenicopterus, the flamingo nests with Cariama, the seriema in the LRT, but with Gavia in the Prum et al. DNA study. Gavia nests with Thalasseus, the tern in the LRT.

Mayr 2004 wrote:
“A recent molecular analysis strongly supported sister group relationship between flamingos (Phoenicopteridae) and grebes (Podicipedidae), a hypothesis which has not been suggested before. Flamingos are long-legged filter-feeders whereas grebes are morphologically quite divergent foot-propelled diving birds, and sister group relationship between these two taxa would thus provide an interesting example of evolution of different feeding strategies in birds.”

Morphologicaly,
grebes are quite similar to loons, like Gavia (Fig. 2), which nests with terns and penguins in the Prum et al. tree AND in the LRT. (Wow! That’s a rare happenstance!)

Then Mayr 2006
found a taxon that had been around awhile Palaelodus ambiguus (Figs. 3–5), that morphologically linked flamingos to grebes. Mayr reports, “Since both grebes and †Palaelodidae are aquatic birds which use their hindlimbs for propulsion, it is most parsimonious to assume that the stem species of (Pan-)Phoenicopteriformes also was an aquatic bird which used its hind limbs for propulsion in the water (Mayr 2004). Palaelodus has “derived skull features of flamingos with leg adaptations for hindlimb propulsion found in grebes.”

Figure 3. From Mayr 2006, who wrote, "Palaelodus sp. (†Palaelodidae; uncatalogued specimen from Alliers in France in the collection of Forschungsinstitut Senckenberg). Note that the upper beak and part of the cranium in B are reconstructed."

Figure 3. From Mayr 2006, who wrote, “Palaelodus sp. (†Palaelodidae; uncatalogued specimen from
Alliers in France in the collection of Forschungsinstitut Senckenberg). Note that the upper beak and part of the cranium in B are reconstructed.”

In the LRT
stork-like Palaelodus (1.5m tall) nests with Rhynchotus, a tinamou. Like Rhynchotus, Palaelodus appears to be fully volant.

Figure x. Data used to score Palaelodus in the LRT. Note the very flamingo-like proportions, but this is a ratite.

Figure 4. Data used to score Palaelodus in the LRT. Note the very flamingo-like proportions, but this is a tall, gracile tinamou.

70 characters and 17 suprageneric taxa later, Mayr 2004 wrote:
“Previously overlooked morphological, oological and parasitological evidence is recorded which supports this hypothesis, and which makes the taxon (Podicipedidae + Phoenicopteridae) one of the best supported higher-level clades within modern birds. It is more parsimonious to assume that flamingos evolved from a highly aquatic ancestor than from a shorebird-like ancestor.” Do you see the fatal flaw here?

Figure x. From Mayr 2006, comparing the flamingo (above) to Palaelodus (middle) and the grebe (below) assuming a gradual transition of traits from grebe to flamingo.

Figure 5. From Mayr 2006, comparing the flamingo (above) to Palaelodus (middle) and the grebe (below) assuming a gradual transition of traits from grebe to flamingo that is not readily apparent because these taxa are not related to one another in the LRT.

Mayr employed 17 suprageneric taxa,
rather than generic taxa, even though his museum has a long list of bird skeletons in its collection. The Mayr 2004 cladogram is very poorly supported with most nodes failing to attain a Bootstrap score over 50. But it did nest Gavia with Phoenicopterus and grebes. Mayr also notes a parasite common to both grebes and flamingos alone among birds. Mayr did include tinamous in his analysis. So, I suppose character scoring is to blame here. Mayr’s hypothesis of relationships (Fig. 5) appears to be untenable. Many other taxa are closer to all three in morphology.

G. Mayr wrote via email upon seeing this cladogram:
“Hmm, to me the trees make little sense. If Palaelodus results within palaeognathous birds, many characters must be incorrectly scored. Furthermore, this exemplifies the pitfalls of laerge-scale cladistzic analyses.
Best wishes,
Gerald Mayr”

Unfortunately
this reply reflects the general view of PhDs. Large scale analyses, as readers know, test more possibilities, giving each taxon more opportunities to nest wherever they most parsimoniously fit.

References
Cracraft J 1981. Toward a phylogenetic classification of the recent birds of the world (Class Aves).Auk98: 681–714.
Mayr G 2004. Morphological evidence for sister group relationship between flamingos (Aves: Phoenicopteridae) and grebes (Podicipedidae). Zoological Journal of the Linnean Society. 140 (2): 157–169. doi:10.1111/j.1096-3642.2003.00094.x. ISSN 0024-4082.
Mayr G 2006. The contribution of fossils to the reconstruction of the higherlevelphylogeny of birds. Species, Phylogeny and Evolution 1 (2006):59–64.
Mayr G 2015. Cranial and vertebral morphology of the straight-billed Miocene phoenicopteriform bird Palaelodus and its evolutionary significance. Zoologischer Anzeiger – A Journal of Comparative Zoology. 254:18–26.
Milne-Edwards A 1863. Mémoire sur la distribution géologique des oiseaux fossiles et description de quelques espèces nouvelles. Annales des Sciences Naturelles (in French). 4 (20): 132–176.
Milne-Edwards, A 1867-1871. Recherches anatomiques et paleontologiques pour servir a l’histoire des oiseaux fos- siles de la France (Paris, G. Masson).
Olson SL, Feduccia A 1980a. Relationships and evolution of flamingos (Aves: Phoenicopteridae). Smithsonian Contributions to Zoology 316: 1–73.

wiki/Palaelodidae
wiki/Palaelodus
Dr. Gerald Mayr

Molecules vs. morphology in bird phylogeny: Prum et al. 2015

As readers know
DNA cladograms do not match morphology cladograms, like the large reptile tree (LRT, 1124 taxa). Today we’ll be looking at some of the ‘strange bedfellows‘ that the Prum et al. 2015 DNA cladograms produced.

The LRT outgroups
include a long line of taxa extending through theropods and Jurassic birds, like Archaeopteryx), and other taxa going all the way back to Devonian tetrapods. That’s a solid out group. At every node the taxa document a gradual accumulation of traits. 76+ (the number may grow) Euornithine birds comprise the in group.

Figure 2. Basal Euornithes/horizontal. Click to enlarge.

Figure 1. Basal Euornithes. Click to enlarge this horizontal view of figure 1.

The Prum et al. cladogram employed 198 euornithine birds,
and nested the ones genetically closest to crocs at the base: Struthio, the ostrich + (Leipoa, the megapode + Chauna, the screamer).

Prum et al. chose two outgroup taxa:
Two crocodilians. No theropods were included. No Jurassic birds were included.

Crocs don’t have feathers.
Their forelimbs are not transformed into wings. Morphologically crocs are not good outgroups for euornithine birds, but, when using DNA, there are no better taxa living today. Unfortunately they do not provide a readily visible gradual accumulation of traits. For those we have pertinent taxa recovered by the LRT (Figs. 1, 2).

Figure 1. Basal euornithes to scale as recovered by the LRT.

Figure 2. Basal euornithes to scale as recovered by the LRT. Basal birds, for the most part, were long-legged forms. Short forms arrive easily by way of neotony as bird hatchlings have short legs. Yanornis is Early Cretaceous.

LRT Clades 1 and 2: Tinamous and Ratites
In the LRT the first clade includes an early Eocene tinamou-like bird, Pseudocrypturus + Apteryx, the kiwi. In the next clade mid-sized tinamous are basal to giant ratites – and all other extant birds.

Prum et al. Clade 1: Ratites and Tinamous
In the Prum et al. cladogram, the giant derived ostrich splits off first, then the smaller rhea, then the even smaller kiwi (Fig. 1), then the giant cassowary and giant emu. These last two are sisters to the clade of tinamous and all members of the Palaeognathae in the DNA study. In the Prum et al. tree, the ostrich is basal to all known ratites – and all other extant birds.

This may strike you as odd.
Generally basal taxa are average to small in size (Fig. 1) and without unusual traits, but the opposite is the case in the Prum et al. cladogram.

LRT Clade 3: Toothed Birds
The next clade in the LRT includes extinct toothed birds, a clade that, perforce, has to be ignored by the Prum et al. DNA study and, for that matter, has little bearing on extant bird evolution. This clade came and went without affecting the living birds. The presence of teeth are a secondary appearance, an atavism in this clade. The basalmost taxon, Changzuiornis, had tiny teeth and most closely resembled the long-snouted, long-legged outgroup tinamous. Later toothed birds had larger teeth, shorter legs and the most derived toothed bird, Hesperornis, had vestigial wings.

Teeth in birds,
whether true teeth with dentine and enamel, or false teeth made of bone or keratin also reappear most obviously in ducks, flamingoes and Pelagornis, the giant petrel. Less obviously tiny bill projections can be found in several other bird bills on close examination.

Prum et al. Clade 2: Neognathae + Galloanseriformes
In the Prum et al cladogram the first neognath clade includes megapodes and chickens on one branch and screamers and ducks in the other. In the LRT megapodes are indeed close to chickens, but ducks are far removed from screamers. Importantly, neither screamers nor megapodes are skeletally similar to the ostrich, their proximal outgroup in Prum et al.

LRT Clade 4: Birds of Prey
Generally tinamous are infrequent flyers and so are basal members of the next clade in the LRT, the long-legged, hooked beak predators, Cariama and Sagittarius. The latter gives rise to short-legged aerial predators like Pandion (ospreys),  Falco (falcons) + Targas (Old World vultures) and Tyto (owls) + Apus (swifts).

Figure 2. Which taxa share more traits? Phoenicopterus, the flamingo nests with Cariama, the seriema in the LRT, but with Gavia in the Prum et al. DNA study. Gavia nests with Thalasseus, the tern in the LRT.

Figure 3. Which taxa share more traits? Phoenicopterus, the flamingo nests with Cariama, the seriema in the LRT, but with Gavia in the Prum et al. DNA study. Gavia nests with Thalasseus, the tern in the LRT.

Phoenicopterus, the derived flamingo is a frequent flyer, but eats while standing with a strongly hooked beak and nests with the similarly gracile basal Cariama. In summary, and heretically, swifts and flamingos nest with birds of prey in the LRT. Prum et al. nest flamingos with short-limbed, straight-billed grebes, like Gavia, and all other shorebirds (Fig. 3). The LRT nests Gavia with short-limbed, straight-billed terns and only a few other shorebirds.

More later.
It’s a big subject.

References
Prum et al. (6 co-authors) 2015. A comprehensive phylogeny of birds (Aves) using targeted next-generation DNA sequencing. Nature 526:569–573. online

Earliest confuciusornithid is Wellnhoferia (Late Jurassic) contra Navalón et al. 2017

Navalón et al. 2017
report on “the earliest representative of the clade” Confuciusornithidae, a bird clade known from hundreds of Early Cretaceous specimens of the genus Confuciusornis (Fig. 1), first reported by Hou et al. 1995. Highlights (= summary) and partial abstract copied below, but the gist is: they found an early Cretaceous confuciusornithid earlier than than other confuciusornithids, but not early enough…

Unfortunately
the Navalón team did not expand their taxon list sufficiently. They should have looked at one of the Solnhofen birds, Wellnhoferia (Fig. 1). It is the earliest known representative of the clade Confuciusornithidae in the present study.

Figure 1. Confuciusornis (early Cretaceous) and Wellnhoferia (Late Jurassic), one of the Solnhofen birds traditionally considered Archaeopteryx.

Figure 1. Confuciusornis (early Cretaceous) and Wellnhoferia (Late Jurassic), one of the Solnhofen birds traditionally considered Archaeopteryx. These two nest together in the LRT apart from most other Solnhofen birds, including the type of Archaeopteryx.

Wellnhoferia (Late Jurassic, Fig. 1) is one of the Solnhofen birds traditionally considered Archaeopteryx (the Solnhofen specimen, or no. 6). It was initially misidentified as Compsognathus and kept in a private collection. Peter Wellnhofer re-identified the specimen as the 6th Archaeopteryx (Wellnhofer 1988a,b). Elzanowski (2001) thought the specimen was generically distinct from the type, so renamed it Wellnhoferia, to honor Wellnhofer.

Elzanowski 2001 reported
the 6th specimen differed from Archaeopteryx in having:

  1. a short tail (16-17 causals)
  2. a nearly symmetrical pattern of pedal rays (toes) 2–4 with metatarsals 2 and 4 of equal length and digit 4 substantially shorter than in Archaeopteryx with only 4 phalanges
  3. large size and details of the pelvic limb are different.

Prior workers overlooked
the circular hole in the proximal humerus, a trait shared with confuciusornids, but not scored in the large reptile tree (LRT, 1122 taxa). Confuciusornis and Welllnhoferia nest together in the LRT and apart from most other Solnhofen birds, including the type of Archaeopteryx. Zhongornis is the outgroup taxon for Confuciusornithids in the LRT.

Mayr et al. (including some guy other than me named D. Peters) 2007 described the tenth Solnhofen bird and did not recognize that Wellnhoferia was distinct from Archaeopteryx. Senter and Robins 2003 supported Elzanowski (2001).

FIgure 2. Wellnhoferia (Archaeopteryx #6) grandis pink highlighting the added tail vertebrae and the humerus with the hole in it, as in Confuciusornis.

FIgure 2. Wellnhoferia (Archaeopteryx #6) grandis pink highlighting the added tail vertebrae and the humerus with the hole in it, as in Confuciusornis.

 

Highlights from Navalón et al. 2017.
“We describe an adult specimen of a confuciusornithid bird from the Huajiying Formation of the Jehol Biota, which contains the earliest representatives of the clade. The new fossil is most similar to the synchronic but immature Eoconfuciusornis zhengi, supporting the validity of the latter taxon. The confuciusornithids from the early (Huajiying Formation) and late (Yixian Formation and Jiufotang Formation) Jehol Biota are morphologically distinct from each other.”

Abstract
“The Huajiying Formation contains the earliest deposits of the Jehol Biota, representing the world’s second oldest (after Solnhofen) avifauna. This avifauna includes the early confuciusornithid Eoconfuciusornis zhengi, the oldest occurrence of this clade and one of the earliest divergences of pygostylian birds. Although E. zhengi shows unique traits, the holotype’s immature age makes comparisons with the better known Confuciusornis sanctus problematic. As a result, the taxonomic validity of E. zhengi is controversial. We describe a small, osteologically adult confuciusornithid from the same deposits as E. zhengi. The new fossil is most similar to E. zhengi but also shares traits with the stratigraphically younger Confuciusornis. The humerus of the new fossil is straighter and more slender, and bears a less dorsally-developed deltopectoral crest compared with similarly-sized and smaller specimens of Confuciusornis. The morphology of the humerus is intermediate between E. zhengi and Confuciusornis and its proximal portion is pierced by a small deltopectoral foramen, absent in the holotype of E. zhengi. However, this foramen is much smaller than in any other confuciusornithid.”

The takeaway
from this blogpost repeats an earlier hypothesis: The initial radiation of birds preceded the Late Jurassic. Solnhofen birds, few of which are congeneric, represent that a wide gamut of taxa, each a representative from that earlier initial radiation.

On a side note
Madagascar separated from Africa 160 million years ago, ten million years prior to the Solnhofen formation and the Solnhofen birds that are found there. On the African side of the split were the ancestors of the ostrich, Struthio. On the Madagascar side were the ancestors of the elephant bird, Aepyornis.

References
Elzanowski A. 2001. A new genus and species for the largest specimen of Archaeopteryx. Acta Palaeontologica Polonica 46(4):519–532.
Hou L, Zhou Z, Gu Y and Zhang H 1995. Confuciusornis sanctus, a new Late Jurassic sauriurine bird from China. Chinese Science Bulletin 40: 1545–1551.
Mayr G, Pohl B, Hartman S and Peters DS 2007. The tenth skeletal specimen of Archaeopteryx. Zoological Journal of the Linnean Society. 149 (1): 97–116.
Navalón G, Meng Q-G, Marugán-Lobón J, Zhang Y, Wang B-P,  Xing H, Liu D and Chiappe LM 2017. Diversity and evolution of the Confuciusornithidae: Evidence from a new 131-million-year-old specimen from the Huajiying Formation in NE China. Journal of Asian Earth Sciences (advance online publication)
doi: https://doi.org/10.1016/j.jseaes.2017.11.005
http://www.sciencedirect.com/science/article/pii/S1367912017306223
Senter P and Robins JH 2003. Taxonomic status of the specimens of Archaeopteryx. Journal of Vertebrate Paleontology 23(4):961–965.
Wellnhofer P 1988. A New Specimen of Archaeopteryx. Science 240(4860):1790–1790.

wiki/Confuciusornis
wiki/Wellnhoferia