Darwin’s finches: Mesozoic style

Originally ‘Darwin’s finches’ =
small birds from the Galápagos Islands west of Ecuador, in the Pacific Ocean.

According to Wikipedia:
The term “Darwin’s finches” was first applied by Percy Lowe in 1936, and popularised in 1947 by David Lack in his book Darwin’s Finches. The most important differences between species are in the size and shape of their beaks, which are highly adapted to different food sources.”

For today’s post, metaphorically speaking, ‘Darwin’s finches’ =
“several variations on a last common ancestor restricted to a small geographic area.”

Similar Mesozoic variations
on a last common ancestor restricted to a small geographic area are also documented in the large reptile tree (LRT) and the large pterosaur tree (LPT). Here (Figs. 1–8), other than Late Cretaceous Pteranodon (Fig. 1), and Middle Jurassic Darwinopterus (Fig. 8), the others (Figs. 2–7), are all known from the Late Jurassic Solnhofen Formation, a lagerstätte representing an archipelago or series of islands, much like today’s Galápagos Islands.

Here
(Figs. 1–8) pictures of closely related taxa tell the story of their own evolution much better than any long-winded explanation. No two are alike. Arrows indicate phylogenetic order.

If you want to know more,
click on each of the images below. When taken to the large image pages at ReptileEvolution.com a small link at the top of each page will take you to one of the species pictured therein. Other links to related taxa are posted on each species’ page.

Pteranodon

Figure 2. The DMNH specimen is in color, nesting between the short crest KS specimen and the long crest AMNH specimen.

Figure 1. The DMNH specimen is in color, nesting between the short crest KS specimen and the long crest AMNH specimen. If you see a female in this diagram, let me know. No two are alike.

Rhamphorhynchus

Figure 2. Rhamphorhynchus specimens to scale. The Lauer Collection specimen would precede the Limhoff specimen on the second row.

Figure 2. Rhamphorhynchus specimens to scale. The Lauer Collection specimen would precede the Limhoff specimen on the second row. No two are alike, but the Vienna specimen is a juvenile of the larger n81 specimen to its right.

Dorygnathus

Figure 8. Click to enlarge. The descendants of Sordes in the Dorygnathus clade and their two clades of pterodactyloid-grade descendants.

Figure 3. Click to enlarge. The descendants of Sordes in the Dorygnathus clade and their two clades of pterodactyloid-grade descendants. No two are alike.

Germanodactylus

Germanodactylus and kin

Figure 4. Click to enlarge. Germanodactylus and kin. No two are alike.

Pterodactylus

The Pterodactylus lineage and mislabeled specimens formerly attributed to this "wastebasket" genus

Figure 5. Click to enlarge. The Pterodactylus lineage (in white) and mislabeled specimens formerly attributed to this “wastebasket” genus (in color boxes). No two are alike.

Scaphognathus

Figure 1. Scaphognathians to scale. Click to enlarge.

Figure 6. Click to enlarge. Only the left three taxa have been identified as Scaphognathus species. Other tiny unnamed specimens are transitional taxa to Pterodactylus or Germanodactylus leading to larger, later taxa. No two are alike.

Archaeopteryx (some of these Solnhofen birds have been renamed)

Figure 3. Several Solnhofen birds, including Archaeopteryx, compared to Ostromia to scale.

Figure 7. Several Solnhofen birds, including Archaeopteryx, compared to Ostromia to scale. No two are alike.

Darwinopterus

Figure 7. Darwinopterus specimens and a few outgroup taxa.

Figure 8. Darwinopterus specimens and a few outgroup taxa. None of these are basal to any pterodactyloid-grade clades. No two are alike. The female (upper right) is associates with an egg.

Unfortunately,
PhDs and other paleo workers who traditionally refuse to trace and reconstruct ‘to scale’ skeletons of taxa under study never get to discover results like these that are only revealed from producing ‘to scale’ graphics like these (Figs. 1–8). Subtleties come through here, en masse, that are lost when looking at individual skeletons in situ one at a time, especially through a microscope, where you don’t get to see ‘the big picture’. Some workers consider such graphics pseudoscience and crankery.

As a result, no other workers
understand or accept the four origins of the pterodactyloid grade arising from phylogenetic miniaturized transitional taxa (Figs. 3, 6) because they omit pertinent tiny and congeneric taxa. Likewise, workers do not yet understand nor accept the radiation of several bird clades having their genesis in Solnhofen basalmost birds. Workers don’t see ‘the big picture’ because of these taxon exclusions.

Rather, too many workers
try to compile a list of specific traits that differentiate one taxon from another. Here we call that, “Pulling a Larry Martin” because it only sometimes leads to greater understanding. The problem is unrelated taxa too often share those same traits by convergence. Here, reconstructions and a confident nesting in the LRT automatically encompass and include ALL the subtle irregularities between taxa that ‘trait seekers’ traditionally overlook.

References

wiki/Darwin’s_finches

What is Alcmonavis poeschli?

Rauhut, Tischlinger and Foth 2019 describe
a disarticulated right forelimb/wing of a ‘non-archaeopterygid avialan theropod’, they named Alcmonavis poeschli specimen SNSB-BSPG 2017 I 133. It is the 13th Solnhofen bird.

The authors report,
“it is a more derived avialan than Archaeopteryx,” which brings up a problem.

Currently there are more than a dozen Solnhofen birds
or pre-birds in the large reptile tree (LRT, 1471 taxa). Many workers, including Rauhut, Tischlinger and Foth, throw them into a taxonomic wastebasket of ‘Archaeopteryx.’ Other authors have shown that some are not congeneric with others and these were noted by Rauhut, et al.

By contrast,
the LRT separates all of Solnhofen birds specifically, and many generically, recovering several at the bases of various Early Cretaceous bird clades. The LRT, employing relatively few forelimb traits and none specific to theropods/birds, nests Alcmonavis with the BSP 1999 I50 specimen identified as Archaeopteryx bavarica (the Munich specimen, Fig. 1), nesting at the base of the Jeholornis clade alongside the #12 specimen (Fig. 1), which nests at the base of the sister clade, the Scansoriopterygidae. Evidently there were enough traits in the new specimen forelimb to do this. I wasn’t sure at first.

Figure 1. Alcmonavis to scale with its sister in the LRT, the Munich specimen.

Figure 1. Alcmonavis to scale with its sister in the LRT, the Munich specimen. The authors did not attempt a reconstruction.

Notably,
Alcmonavis is twice the size of the Munich specimen (Fig. 1). The authors write, “Here we report on a new paravian specimen from the Lower Tithonian Mörnsheim Formation, representing the second theropod specimen from this unit, which overlies the Altmühltal Formation. The new specimen represents the largest avialan theropod yet recorded from the Jurassic and provides further evidence on the forelimb anatomy and the origin of flapping flight in basal avialans.”

The authors note that Alcmonavis
was found in the formation immediately above the one that yielded the majority of Solnhofen birds, including the Munich specimen.

Regarding the numbers and names, the authors write, 
“We propose to retain the original numbering of specimens, even if one accepts the different generic assignments, in order to avoid confusion between the recent and older literature. Given the gradual assembly of the avialan body plan and the general similarity of the basalmost members of this clade, it might be justified to simply talk about ’urvogel specimens’ instead of using the generic name Archaeopteryx, to thus accommodate the taxonomic uncertainty. Accordingly, the specimen described here should be regarded as the 13th urvogel specimen from the Solnhofen Archipelago.” 

This is confirmation of a practice already in place.
In the LRT and here at ‘Heresies’, all specimens from the Solnhofen limestones have been called, ‘Solnhofen birds’ for several years now. This leaves room for some specimen to be renamed when more of them are added to phylogenetic analyses, as documented in the LRT. The term ‘urvogel’ goes back to the false assumption that one ‘ur’ was present, rather than the large radiation already documented in the LRT.

The authors lament many layers of difficulty
in comparing the forelimb of Alcmonavis to those of other Solnhofen birds based on size and exposure, various proportions and robust qualities. As mentioned earlier, the LRT had no such problems using DGS methods to extract comparative data. Summarizing, the authors state, “despite the overall similarity and very similar proportions, the new specimen shows numerous small differences from Archaeopteryx, precluding a referral to this taxon. It is furthermore clear that SNSB-BSPG 2017 I 133 also cannot be referred to Ostromia or to any other known theropod taxon.”

“The phylogenetic analysis resulted in more than 99,999 trees with a length of 2690 steps. The strict consensus is rather well resolved and includes monophyletic Maniraptora, Paraves and Avialae with equivalent taxonomic contents to other recent analyses.”

Unfortunately the authors include only one taxon for Archaeopteryx.
They nest Alcomonavis between Archaeopteryx and higher birds, oblivious to the effects of taxon exclusion on their tree topology. Little else needs to be said. Deleting/ omitting/ ignoring key taxa is inappropriate at this stage of our understanding of Solnhofen birds.

Here is yet another case
where more taxa would have helped the original authors, not more characters. Taxon exclusion continues to be the number one problem in paleontology, not just with Jurassic birds.

Contra the title of Rauhut et al. 2019,
the new taxon is indeed an archaeopterygid, despite its size.


References
Rauhut OWM, Tischlinger H and Foth C 2019. A non-archaeopterygid avialan theropod from the Late Jurassic of southern Germany. elifesciences.org 2019;8:e43789. DOI: https://doi.org/10.7554/eLife.43789

The Daiting specimen is not Archaeopteryx

Today
a break from a review of the SVP 2018 abstracts.

A new paper by Kundrát, et al. 2018
re-describes the Daiting specimen (Tischlinger 2009) attributed to Archaeopteryx and given a specific name A. albersdorfi (SNSB BSPG VN-2010/1Kundrát et al. 2018, Late Jurassic, Lower Tithonian; Figs. 1, 2). 

Figure 1. The Daiting specimen attributed to Archaeopteryx in white and UV light. Note the short coracoid. This is not a flapping tetrapod.

Figure 1. The Daiting specimen attributed to Archaeopteryx in white and UV light. Note the short coracoid. This is not a flapping tetrapod.

The skull of the Daiting specimen
is newly reconstructed here (Fig. 2). The former postorbital is now the squamosal. The former squamosal is here identified as three bones layers atop one another. The bones of the mandible are newly interpreted here.

Figure 2. The skull of the Daiting specimen wrongly attributed to Archaeopteryx reconstructed from µCT scans.

Figure 2. The skull of the Daiting specimen wrongly attributed to Archaeopteryx reconstructed from µCT scans. Some bones are reidentified here.

Unfortunately,
the large reptile tree (LRT, 1313 taxa; subset Fig. 3) nests the Daiting specimen outside of the birds, between Sinovenator and Xiaotingia.

Figure 3. Subset of the LRT focusing on basal birds and pre-bird theropods. Note many of the various Solnhofen birds nest apart from one another and the Daiting specimen nests outside the birds (Aves).

Figure 3. Subset of the LRT focusing on basal birds and pre-bird theropods. Note many of the various Solnhofen birds nest apart from one another and the Daiting specimen nests outside the birds (Aves). Preview: note the nesting of the four included Anchiornis specimens. 

Kundrát et al. provided several cladograms
based on data sets provided by Xu et al. 2011; Turner et al. 2012 and Godefroit et al. 2013. They “unanimously resolved [the Daiting specimen] as both a basal avialan and an archaeopterygid, but does not unequivocally discriminate between a paraphyletic or monophyletic Archaeopteryx.” 

  1. Xu et al. 2011 cladogram: nests the Daiting specimen between Anchiornis + Xiaotingia and Archaeopteryx + Wellnhoferia, all derived from SapeornisYanornis clade.
  2. Xu et al. 2011cladogram (Xiaotingia deleted): nests the Daiting specimen between a SapeornisYanornis clade and Archaeopteryx + Wellnhoferia,
  3. Turner et al. 2012 cladogram: nests the Daiting specimen basal to a different Sapeornis clade, all derived from Archaeopteryx.
  4. Turner et al. 2012 cladogram (3 taxa deleted): nests the Daiting specimen basal to a different Sapeornis clade, all derived from Archaeopteryx.
  5. Godefroit et al. 2013 cladogram: nests the Daiting specimen with Archaeopteryx, basal to the BalaurRahonavis clade, all derived from Xiaotingia.

Not all of the nodes in the above cladograms
include a gradual accumulation of traits in all derived taxa.

Kundrát et al. report:
“Archaeopteryx albersdoerferi is the only Bavarian archaeopterygid that exhibits co-ossification of the carpals and metacarpals, differing from modern flying birds in that the distal postaxial carpal (usually missing – perhaps cartilaginous – in other archaeopterygid specimens; (Wellnhofer 2009)) co-ossified with the metacarpal of the major digit rather than with the semilunate and postaxialmetacarpal.”

“The most noteworthy feature of Archaeopteryx albersdoerferi is that it accummulated several characteristics of maturity (discussed above) during the juvenile period of ontogeny that were not seen either in smaller or in larger specimens of Archaeopteryx lithographica.”

The coracoids of the Daiting specimen
are still rather disc-like in appearance, not strap-like as in Xiaotingia and birds. The Daiting specimen was not a flapping taxon, or not a good flapping taxon. That comes at the next node.

Figure 4. Pectoral girdle of the Daiting specimen wrongly attributed to Archaeopteryx showing the clavicle (cv=furcula), scapula (sc), and the disc-like coracoids (co). Strap-like coracoids occur in more derived taxa and this shape marks the genesis of flapping.

Figure 4. Pectoral girdle of the Daiting specimen wrongly attributed to Archaeopteryx showing the clavicle (cv=furcula), scapula (sc), and the disc-like coracoids (co). Strap-like coracoids occur in more derived taxa and this shape marks the genesis of flapping.

Earlier we looked at the variety of taxa present in Solnhofen birds,
(Fig. 3, 5) all of which have been called Archaeopteryx at their first publication. Later authors have renamed several of them. Remember, you can’t determine a genus or species without the context of a phylogenetic analysis.

Figure 3. Several Solnhofen birds, including Archaeopteryx, compared to Ostromia to scale.

Figure 5. Several Solnhofen birds, including Archaeopteryx, compared to Ostromia to scale.

References
Kundrát M, Nudds J, Kear BP, Lü J-C and Ahlberg P 2018. The first specimen of Archaeopteryx from the Upper Jurassic Mörnsheim Formation of Germany. Historical Biology 31(1):3-63.
Tischlinger H 2009. Der achte Archaeopteryx – das Daitinger Exemplar. Archaeopteryx. 27:1–20.
Wellnhofer P 2009. Archaeopteryx—the Icon of Evolution. München: Friedrich Pfeil.

You heard it here first: No two Archaeopteryx look the same.

The science section
of the online British news outlet, the Guardian, reported on the 12th (Haarlem) specimen of Archaeopteryx re-named Ostromia. You can read that story online here.

From the Guardian article:
“Of the Twelve Specimens Once Known as Archaeopteryx (SPOKA), only nine continue to carry that name. At the end of the day, we can’t all be winners. But even within that group of nine specimens, no two Archaeopteryx look the same. Rauhut and colleagues report that there is significant variation in the size, shape, spacing and orientation of the teeth, as well as differences in body size between the different specimens. This could be an ontogenetic pattern, with larger individuals representing adults with more developed dentition. Alternatively, as the Solnhofen Basin constituted a tropical island archipelago during the Late Jurassic, these differences in body size and dentition could be interpreted as island adaptations. Similarly to today’s Galápagos finches, different populations of Archaeopteryx may have adapted to different insular environments.”

We looked at
Solnhofen birds (Fig. 1) earlier here and Ostromia here. Since 2015 readers have known that no two Archaeopteryx specimens were identical and that phylogenetic analysis split them apart to nest at the base of each one of all the Cretaceous bird clades. And yes, we know of an embryo archaeopterygid, the Liaoning embryo most closely related to the London specimen.

Figure 3. Several Solnhofen birds, including Archaeopteryx, compared to Ostromia to scale.

Figure 3. Several Solnhofen birds, including Archaeopteryx, compared to Ostromia to scale.

It really is time to
run these birds through analysis and either affirm, modify or invalidate the results of the large reptile tree. And it should be done by someone with firsthand access to all the specimens. That would be a good test.

References
Elzanowski, A., 2002. Archaeopterygidae (Upper Jurassic of Germany) In: Chiappe LM, Witmer LM, eds. Mesozoic Birds. Above the Heads of Dinosaurs. Berkeley: University of California Press. 129-159.
Foth C, Rauhut OWM. 2017. Re-evaluation of the Haarlem Archaeopteryx and the radiation of maniraptoran theropod dinosaurs. BMC Evolutionary Biology 17:236

https://www.theguardian.com/science/2018/feb/21/the-new-specimen-forcing-a-radical-rethink-of-archaeopteryx

The 11th Archaeopteryx: closer to Sapeornis

Figure 1. The 11th specimen attributed to Archaeopteryx in situ. See figure 2 for a reconstruction. This specimen remains in private hands without a museum number.

Figure 1. The 11th specimen attributed to Archaeopteryx in situ. See figure 2 for a reconstruction. This specimen remains in private hands without a museum number. Note all the soft tissue feathers preserved here.

Archaeopteryx number 11
(Figs. 1, 2) has no museum number and is in private hands, but Foth et al. 2014 published a description in Nature. These authors unfortunately considered this specimen just another Archaeopteryx, but one well supplied with feather impressions. In the large reptile tree (LRT, subset Fig. 3) this Solnhofen bird nests at the base of the node that produced two specimens of Sapeornis, a clade convergent with Euronithes in having a pygostyle.  The 11th specimen is complete and articulated, but lacks a large part of the cranium.

Figure 2. Most of the complete Solnhofen birds, including Archaeopteryx and the eleventh specimen to scale.

Figure 2. Most of the complete Solnhofen birds, including Archaeopteryx and the eleventh specimen to scale.

Foth et al. 2014 do not mention
the lack of a sternum. Sapeornis likewise lacks a sternum even though more primitive taxa have one.

Figure 4. The eleventh Archaeopteryx nests with Sapeornis.

Figure 4. The eleventh Archaeopteryx nests with Sapeornis.

At first glance
this appears to be an ordinary Archaeopteryx. However, when you put the dividers on the bones you find that it differs in subtle ways from the holotype and is more similar to Sapeornis and its sisters. As I mentioned yesterday, it would be a good thing for all early bird workers to start considering the Solnhofen birds individual genera, not a single genus. It’s just a lazy habit we have to overcome.

References
Foth C, Tischlinger H and Rauhut OWM 2014. New specimen of Archaeopteryx provides insights into the evolution.of pennaceous feathers. Nature 511:79–83.DOI: 10.1038/nature13467

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

Jianianhualong: not a bird-like troodontid — it’s a troodontid-like bird

Revised May 11, 2017 with new nesting for Chiappeavis. 

Once again, taxon exclusion issues arise
Colleagues, we have to let the taxa nest themselves. Don’t restrict your inclusion sets to the short list of taxa you prefer! In the Jianianhualong paper a long list of candidate taxa were excluded, including its actual proximal sisters (Fig. 6). And they missed the other big headline that should have attended this new taxon. See below.

Figure 1. Jianianhualong tengi in situ. This is the largest among the early birds, a fact overlooked by the Xu et al. 2017. Think of Jianianhualong as a giant Archaeopteryx!

Figure 1. Jianianhualong tengi in situ. This is the largest of the early birds, a fact overlooked by the Xu et al. 2017. Think of Jianianhualong as a giant Archaeopteryx!

Xu et al. 2017
bring us a new genus of theropod dinosaur with feathers, Jianianhualong tengi (DLXH 1218; Yixian Formation, Early Cretaceous; Fig. 1). They nested their new find in an unresolved clade including the non-bird troodontid, Sinornithoides (Fig. 5). Notably they did not resolve Solnhofen birds (Archaeopteryx’ specimens), troodontids and dromaeosaurids. That should have been a red flag that more effort was needed to weed out bad scores in their matrix. Maybe a reconstruction would have helped? (Fig. 3).

FIgure 2. GIF animation of the skull of Jianianhualong showing original tracing in line art and colorized bones (DGS) used to create a reconstruction (Fig. 3).

FIgure 2. GIF animation of the skull of Jianianhualong showing original tracing in line art and colorized bones (DGS) used to create a reconstruction (Fig. 3).

Here
in the large reptile tree (LRT, 1004 taxa) Jianianhualong tengi nests strongly with sapeornithid birds, despite its long bony tail, short forelimbs and large size, all atavistic traits retained in this one of the first flightless birds and certainly one of the first large flightless birds. This aspect was overlooked by Xu et al. 2017 as they mistakenly considered this a feathered non-bird troodontid. It is a bird. A big flightless bird.

Figure 3. Reconstruction of the skull of Jianianhualong based on DGS tracings in figure 2.

Figure 3. Reconstruction of the skull of Jianianhualong based on DGS tracings in figure 2.

If you think the long tail of Jianianhualong is an issue…
Archaeopteryx recurva (the Eichstaett specimen) nests with Jianianhualong and it has a long bony tail, too.

Figure 4. Colorizing the bones of Jianianhualong helps separate them from other elements on the matrix.

Figure 4. Colorizing the bones of Jianianhualong helps separate them from other elements on the matrix better than simply dropping a two letter abbreviation somewhere on the bone.

If you think the large size of Jianianhualong is an issue…
think of it like an early ostrich, flightless with no sternum, a giant Archaeopteryx in the Early Cretaceous, running from more primitive dinosaur-eating theropods.

Figure 5. The Xu et al. cladogram that nests Jianianhualong with troodontids. Note the loss of resolution at important nodes. Compare to the LRT in figure 6.

Figure 5. The Xu et al. cladogram that nests Jianianhualong with troodontids. Note the loss of resolution at important nodes. Compare to the LRT in figure 6. The LRT is fully resolved with more taxa.

Unfortunately
Xu et al. did not test taxa that actually nest closer to Jianianhualong, using an antiquated matrix with only two Solnhofen birds. Xu et al. report, “The discovery of Jianianhualong provides direct evidence for the presence of pennaceous feathers in an unquestionable troodontid theropod.” Since all birds are troodontids in the LRT this statement is true. However, Xu et al. were not thinking that birds arose from troodontids (Fig. 5), so this became a surprising discovery for them. As in so many other cases discussed herein, character traits come as no surprise when the taxon in question is correctly nested.

Fgure 6. Subset of the LRT focusing on birds and their immediate ancestors. Note the nesting of Jianianhualong with Sapeornis.

Fgure 6. Subset of the LRT focusing on birds and their immediate ancestors. Note the nesting of Jianianhualong with Sapeornis.

I just add taxa
and the software/cladogram does the rest. No initial bias. Reconstructions help. So does colorizing the bone. In this case, at least, working from the photo with DGS was more instructive and better able to demonstrate observations to others than traditional firsthand access labeled with small two-letter abbreviations.

Xu et al. 2014
made a headline out of the asymmetric feathers found with Jianianhualong. In the present context, Jianianhualong is derived from volant ancestors (Figs. 1, 6). So, asymmetry is not exceptional, but expected. Xu et al. reported, “Most significantly, the taxon has the earliest known asymmetrical troodontid feathers, suggesting that feather asymmetry was ancestral to Paraves.” The entire statement is false under the present hypothesis of interrelationships.

The unfortunate return of ‘modular evolution.”
Xu et al cite references to the concept of ‘modular (mosaic) evolution‘ which is based on invalid phylogeny. Please avoid ‘modular evolution’. That’s not how evolution works in the real world.

References
Xu X, Currie P, Pittman M, Xing L, Meng QW-J, Lü J-C, Hu D and Yu C-Y 2017. Mosaic evolution in an asymmetrically feathered troodontid dinosaur with transitional features. Nature Communications DOI: 10.1038/ncomms14972.

Let’s take out all Solnhofen birds except Archaeopteryx from the LRT

Figure 1. Theropod subset of the LRT focusing on birds and bird mimics. Only one Archaeopteryx, the holotype, nests here with Enantiornithes.

Figure 1. Theropod subset of the LRT focusing on birds and bird mimics. Only one Archaeopteryx, the holotype, nests here with Enantiornithes.

Traditional cladograms include
only one Solnhofen bird, typically labeled Archaeopteryx. Whether they use the holotype specimen or not, I don’t know. Earlier the large reptile tree (LRT, subsets Figs. 1, 2) added several Solnhofen birds, many workers continue to call Archaeopteryx, while others have given new generic names. A recent paper by Wang and O’Connor 2017 on pygostyles brought this subject back to the table. They recovered four different sorts of pygostyles, but did not recognize four convergent origins for the pygostyles due to (I thought at the time) lacking more than one Archaeopteryx specimen. It’s time to test that assertion.

As reconstructions show
the variety of Solnhofen birds has been largely, but not completely overlooked. In any case the variety is certainly apparent and a revision of the genus Archaeopteryx is long overdue given the interest in every new specimen.

So, what happens to the LRT when only one Archaeopteryx (the holotype) is employed?

< See figure 1.
There is no change in the tree topology, other than the loss of six Solnhofen bird taxa (Fig. 2). The holotype Archaeopteryx continues to nest within Enantiornithes, an extinct bird clade.

Taxon deletion is a good test

Figure 2. Subset of the LRT with seven Solnhofen birds included.

Figure 2. Subset of the LRT with seven Solnhofen birds included. Note their basal positions in the several basal bird clades. This chart, by implication, demonstrates that the first birds preceded the Solnhofen Formation.

Having seven Solnhofen birds
in a cladogram illuminates the origin of birds, the origin of enantiornitine birds, the origin of scansoriopterygid birds and the origin of ornithuromorph birds all from Late Jurassic Solnhofen taxa, something we haven’t had until this point. This is what Wang and O’Connor 2017 lacked and so their report on pygostyles was unnecessarily incomplete.

I encourage all bird workers
to include as many Solnhofen birds as possible in their phylogenetic analyses, and for at least one of them (hopefully more) to revise their taxonomy to include more genera. That would make a great PhD thesis.

References
Wang W and O’Connor JK 2017. Morphological coevolution of the pygostyle and tail feathers in Early Cretaceous birds. Vertebrata PalAsiatica 2017:10: 55:3: 1-26.

Jurassic birds took off from the ground – SVP abstracts 2016

Everyone knows:
Ground up hypothesis – 

implies and includes flapping, always has. Birds flap, always have, at least since the elongation and locking down of the coracoid in ancestral troodontids.

Trees down hypothesis –
has always implied gliding. Gliders don’t flap, never have.

But
baby birds dropping out of trees always flap. It’s what they do. But that fact is often ignored in bird origin videos.

And, as everyone knows by now…
young birds with pre-violant wings flap them like crazy when climbing bipedally — even vertical tree trunks… also something several animated bird origin videos ignore, perhaps because of one glaring opposite extant example: the young wet hoatzin that struggles to climb with all four limbs.

With that preamble…Habib et al. 2016 provide us
a hypothesis on the origin of bird flight that appears to ignore trees and experimental work with pre-volant birds and goes straight to take-off from flat ground. Is that okay?

From the abstract:
“Many small non-avian theropods possessed well-developed feathered forelimbs, but questions remain of when powered flight evolved and whether it occured more than once within Maniraptora. Here, using a first principles modeling approach, we explore these questions and attempt to determine in which taxa takeoff and powered flight was possible. Takeoff is here defined as a combination of both the hindlimb driving the ballistic launch phase, and the wing-based propulsion (climb out). [1]

“Microraptor, Rahonavis, [2] and all avian specimens generated sufficient velocity during leaping or running for takeoff. We re-ran our analysis factoring in life history changes that can alter the flight capability in extant avians, such as egg retention and molting, to examine how these would influence take off capacity. Of the two, molting shows the most significant effects.

“When these results are coupled with work detailing the lack of arboreal features among non-avian maniraptorans and early birds, they support the hypothesis that birds achieved flight without a gliding intermediary step, something perhaps unique among volant tetrapod clades.” [3] [4] [5]

Figure 2. Cosesaurus running and flapping - slow.

Figure 1. Cosesaurus running and flapping – slow.

Notes

  1. Interesting that Habib et al. ignore the presence of trees, which are key to Dial’s hypothesis (updated in Heers et al. 2016)  and opts to go straight from ground to air. That kind of ignores key work, doesn’t it? You might recall that Dr. Habib became famous as the author of the infamous but popular forelimb quad launch hypothesis for pterosaurs.
  2.  Microraptor and Rahonavis are NOT in the lineage of birds in the LRT, but both show how widespread long feathered wings were in Theropoda. The former has elongate coracoids by convergence. The latter does not preserve coracoids, fingers or feathers, but does have the long forearm that might imply bird-like proportions for missing bones… or not.
  3. Apparently Habib et al. assume that pterosaurs and bats originated as gliders when present largely ignored evidence indicates exactly the opposite. Cosesaurus (Fig. 1) was a pterosaur precursor with elongate coracoids, unable to fly, but able to flap. Bats rarely glide, so it is unlikely that they did so primitively. Lacking coracoids, bats employ elongate clavicles to anchor flight muscles.
  4. Okay, so remember the preamble (above) about gliding and trees. When Habib et al. bring up ‘a gliding intermediary step‘, they are implying the presence of trees (high places) in competing and validated-by-experiment hypotheses for the origin of bird flight  — which they are ignoring. They also ignore the fact that baby birds don’t glide when they fall out of trees. They flap like their lives depend upon it. I find those omissions odd, but its not the first time pertinent work has been ignored in paleontology.
  5. In the LRT Xiaotingia (Fig. 2) is the most primitive bird-like troodontid to have elongate coracoids and so may have been the first flapper in the lineage.
Figure 1. Xiaotingia with new pectoral interpretation. See figure 3 for new tracing.

Figure 2. Xiaotingia with new pectoral interpretation.

References
Habib M, Dececchi A, Dufaault D and Larsson HC 2016. Up, up and away: terrestrial launching in theropods. Abstract from the 2016 meeting of the Society of Vertebrate Paleontology.
Heers AM, Baier DB, Jackson BE & Dial  KP 2016. 
Flapping before Flight: High Resolution, Three-Dimensional Skeletal Kinematics of Wings and Legs during Avian Development. PLoS ONE 11(4): e0153446. doi:10.1371/journal.pone.0153446
http: // journals.plos.org/plosone/article?id=10.1371/journal.pone.0153446

YouTube video showing birds running up tree trunks while flapping with nonviolent wings

ScienceNews online promo.

The geologically oldest Archaeopteryx (#12)

Updated November 10, 2016 with higher resolution images of the specimen. The new data moved the taxon over by one node. 

Not published yet in any academic journal,
but making the news in the popular press in Germany to promote a dinosaur museum (links below) is the geologically oldest Archaeopteryx specimen (no museum number, privately owned?). Found by a private collector in 2010, the specimen has been declared a Cultural Monument of National Significance. It is 153 million years old, several hundred thousand years older than the prior oldest Archaeopteryx. It is currently on  display at a new museum, Dinosaurier-Freiluftmuseum Altmühltal in Germany, about 10 kilometers from where the fossil was found.

Figure 1. The new oldest Archaeopteryx in situ with color tracings of bones.

Figure 1. The new oldest Archaeopteryx in situ with color tracings of bones. The ilium has been displaced to the posterior gastralia, or is absent. I cannot tell with this resolution.

Figure 1b. Archaeopteryx 12 in higher resolution.

Figure 1b. Archaeopteryx 12 in higher resolution.

So is it also the most primitive Archaeopteryx?
No. But it nests as the most primitive scansioropterygid bird. As we learned earlier, the Solnhofen birds formerly all considered members of the genus Archaeopteryx (some of been subsequently recognized by certain authors as distinct genera) include a variety of sizes, shapes and morphologies (Fig. 3) that lump and separate them on the large reptile tree. The present specimen has been tested, but will not be added to the LRT until it has a museum number or has been academically published (both seem unlikely given the private status). Given the additional publicity the specimen is now in the LRT.

The fossil is wonderfully complete and articulated
and brings the total number of Solnhofen birds to an even dozen.

This just in
Ben Creisler reports, “The fossil specimen was originally found in 2010 in fragmented condition and took great effort to prepare and piece together as it now appears.”

Figure 2. Reconstruction of the geologically oldest Archaeopteryx, now nesting at the base of the Scansoriopterygidae.   Note the large premaxillary teeth and short snout on a relatively small skull.

Figure 2. Reconstruction of the geologically oldest Archaeopteryx, now nesting at the base of the Scansoriopterygidae. Note the large premaxillary teeth and short snout on a relatively small skull.

Compared to other Archaeopteryx specimens
you can see the new one is among the smallest (Fig. 3) and has a distinct anatomy.

Figure 2. Several Archaeopteryx specimens. The geologically oldest one, (at bottom) is among the smallest and most derived, indicating an earlier radiation than the Solnhofen formation.

Figure 2. Several Archaeopteryx specimens. The geologically oldest one, (at bottom) is among the smallest and most derived, indicating an earlier radiation than the Solnhofen formation.

References
Spektakulaerer-Fund-kommt-in-Ausstellung-article
originalskelett-eines-archaeopteryx-zu-sehen.html
auf-zum-archaeopteryx

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