Pandion, the osprey, joins the LRT

And the osprey,
Pandion haliaetus (Linneaus 1758) joins the large reptile tree (LRT, 1124 taxa) at the base of (owls + swifts) + (Old World vultures + falcons). The secretary bird, Sagittarius, and the terror birds are proximal outgroups.

Figure 1. Pandion, the osprey, nests at the base of the birds of prey, sans the secretary bird and seriema.

Figure 1. Pandion, the osprey, nests at the base of the birds of prey, sans the secretary bird and seriema.

So the osprey is a basal
short-legged, arboreal birds-of-prey.

Wikipedia reports,
“The osprey differs in several respects from other diurnal birds of prey. Its toes are of equal length, its tarsi are reticulate, and its talons are rounded, rather than grooved. The osprey and owls are the only raptors whose outer toe is reversible, allowing them to grasp their prey with two toes in front and two behind. It has always presented something of a riddle to taxonomists, but here it is treated as the sole living member of the family Pandionidae, and the family listed in its traditional place as part of the order Falconiformes.”

References
Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.

wiki/Osprey

 

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Pelagornis is a giant gannet in the LRT.

Quickly becoming one of the most famous of all birds
because of its great size and teeth, Pelagornis is, evidently, still a bird of mystery in the world of paleo-taxonomy.

Figure 1. Pelagornis skeletal elements.

Figure 1. Pelagornis skeletal elements.

Wikipedia reports,
Pelagornis [was] probably rather close relatives of either pelicans and storks, or of waterfowl, and are here placed in the order Odontopterygiformes to account for this uncertainty. Like many pseudotooth birds, it was initially believed to be related to the albatrosses in the tube-nosed seabirds (Procellariiformes), but subsequently placed in the Pelecaniformes where it was either placed in the cormorant and gannet suborder (Sulae) or united with other pseudotooth birds in a suborder Odontopterygia.

Figure 2. Skull of Morus bassanus the Northern gannet. This taxon is most similar to Pelagornis in the LRT.

Figure 2. Skull of Morus bassanus the Northern gannet. This taxon is most similar to Pelagornis in the LRT.

If experts can’t nest Pelagornis with certainty
based on rather complete morphology, then we have a problem. With the addition of the Northern gannet, Morus bassanus, Pelagornis nests with it with certainty in the large reptile tree (LRT, 1032 taxa).

Figure 3. Skeleton of Morus bassanus, the Northern gannet.

Figure 3. Skeleton of Morus bassanus, the Northern gannet.

Pelagornis chilensis (Lartet 1857, Mayr and Rubilar-Rogers 2010; Miocene; MNHN SGO.PV 1061) is an extinct giant soaring bird related to the gannet Macronectes. Bony, not true teeth, developed along the jaw margins. The external naris was divided by bone. Mayr and Rubilar-Rogers reported, “We finally note that the phylogenetic affinities of bony-toothed birds still have not been convincingly resolved.”

Figure 4. The gannet (genus: Morus) in vivo. Note the diving pose below.

Figure 4. The gannet (genus: Morus) in vivo. Note the diving pose below.

Morus bassanus (Linneaus 1758, extant; 100cm long) is the Northern gannet. Here the nasal has extended over the external naris to prevent water from entering the nose of this plunge diver. Secondary nostrils appear inside the mouth. The keratin at the jaw rims appears to form tiny teeth (Fig. 2). Compare to the much larger Pelagornis (Fig. 1).

Earlier we looked at the plunge diving possibility of the outwardly similar Late Jurassic pterosaur, Germanodactylus.

References
Lartet E 1857. Note sur un hum´erus fossile d’oiseau, attribu ´e `a un tr `es-grand palmip`ede de la section des Longipennes. Comptes rendus hebdomadaires des S´eances de l’Acad´emie des Sciences (Paris) 44:736–741.
Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.
Mayr G and Rubilar-Rogers D 2010. Osteology of a new giant bony-toothed bird from the Miocene of Chile, with a revision of the taxonomy of Neogene Pelagornithidae. Journal of Vertebrate Paleontology 30(5):1313-1340.

wiki/Macronectes
wiki/Pelagornis
wiki/Gannet

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

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

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.

 

 

 

 

 

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

Old data (from 1896) nests the elephant bird, Aepyornis, with the ostrich, Struthio

Longtime readers know
I like to make repairs and get things right, whether working from published papers or my own images and data. And longtime readers know I don’t always get things right the first time, usually for good reason (see below). I’ve been looking for Andrews 1896 for several weeks and finally got it. All the earlier problems could have been avoided if I had the data earlier that I have now. Alas, that’s just how it goes…

Figure 1. Aepyornis maximus along with eggs, the largest known. The new skull replaces the original one.

Figure 1. Aepyornis maximus along with eggs, the largest known. The new skull replaces the original one.

Earlier data on the skull of the elephant bird,
Aepyorniscame from a photograph of a commercially available restored cast. Unfortunately, the restoration included a little too much imagination and did not match the only other data currently (and most recently) available (Fig. 2, Andrews 1896).

The data from the embryo in the giant egg attributed to Aepyornis,
did not contribute to the current matrix scoring. That would be akin to creating a chimaera. However, after the fact, it’s noteworthy that the embryo still has ostrich traits not found in the present adult skull data for Aepyornis. The fragile palatal and cheek regions were not preserved or collected in the adult. The fragile cheek regions were not yet developed (or lost in the debris) of the embryo.

Figure 4. NatGeo embryo compared to Struthio and adult Aepyornis. The original maxilla is reinterpreted as the palatine. The original premaxilla is a fused premaxilla + maxilla. The original Nat Geo skull was put together in computer software from scattered parts. Mesethmoid inverted in revision. Aepyornis does not have bulbous squamosals found in Struthio and the NatGeo embryo. Not to scale.

Figure 2. NatGeo embryo compared to Struthio and adult Aepyornis. The original maxilla is reinterpreted as the palatine. The original premaxilla is a fused premaxilla + maxilla. The original Nat Geo skull was put together in computer software from scattered parts. Mesethmoid inverted in revision. Aepyornis does not have bulbous squamosals found in Struthio and the NatGeo embryo. Not to scale. The mystery of the embryo is coming into clearer focus with the latest elephant bird skull data and taxonomy.

All earlier posts
and ReptileEvolution.com pages regarding Aepyornis have been repaired. Good science makes repairs all the time. Better data is always welcome. Every hypothesis remains hypothetical, until it is confirmed over and over again through testing.

Using commercially available skulls for data
is still a good idea, but it’s also a good idea to see which parts are real and which are restored with clay. I don’t know if several skull parts from several specimens of Aepyornis were all put together to produce the skulls currently found in museums and skull shops. Andrews 1896 reports the material he published came from two. Better to take data from one specimen than to make a chimaera of several specimens, because problems like this tend to happen. Sometimes you take what you can get.

Figure x. Bird giants in the bird subset of the LRT.

Figure 3. Bird giants in the bird subset of the LRT.

This should make certain readers happy
that Aepyornis returns to the ratites. I’m happy that better data has come forth. The latest DNA tests prefer Aepyornis to nest with the kiwi. Morphology leans toward the ostrich. With the new nesting of the elephant bird Casuarius, the cassowary, nests between tinamous and ostriches + elephant birds.

References
Andrews CW 1896. On the skull, sternum, and shoulder-girdle of Aepyornis. Ibis, Seventh Series, 2:376-389.
Balanoff AM 2003. Osteological description of an embryonic elephant bird (Ratitae: Aepyornis) using high-resolution X-ray computed tomography, with a discussion of growth in Aepyornis. M.S. thesis, The University of Texas, Austin, Texas, 175 pp.
Balanoff AM and Rowe T 2007. Osteological description of an embryonic skeleton of the extinct elephant bird, Aepyornis (Palaeognathae: Ratitae). Journal of Vertebrate Paleontology 27(sp9):1–53.
Geoffroy Saint-Hilaire I 1851. [Note sur les onze espèces nouvelles do Trochilidés de M. Bourcier.] Compt. Rend. de l’Acad. Sci 32:188.
Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.
Temminck 1815. Histoire naturelle generale des pigeons et des gallinaces.
Accompagne de planches anatomiques. 3: 552–747

wiki/Rhynchotus
wiki/Cassowary
wiki/Ostrich
wiki/Aepyornis