John Ostrom: The man who saved dinosaurs

Saw this on Facebook recently
The following is from an online Yale Alumni Magazine article (link below) by award-winning author, Richard Conniff, July/August 2014.

Preview
“In his book The Riddle of the Dinosaur, science writer John Noble Wilford added that Bakker “was the young Turk whose views could be dismissed by established paleontologists. Ostrom, however, could not be ignored.” Late in 1969, Ostrom took the challenge directly to the North American Paleontological Convention in Chicago, declaring in a speech that there was “impressive, if not compelling” evidence “that many different kinds of ancient reptiles were characterized by mammalian or avian levels of metabolism.” Traditionalists in the audience responded, Bakker later recalled, with “shrieks of horror.” Their dusty museum pieces were threatening to come to life as real animals.”

Figure 1. John Ostrom, from young paleo stud to elderly professorial type.

Figure 1. John Ostrom, as a young paleo stud and as an elder statesman several decades later demonstrating a degree of isometry and allometry during ontogeny.

“Against this false negative, Ostrom laid out the positive evidence, listing more than 20 anatomical similarities between Archaeopteryx and various dinosaurs. It wasn’t just that Ostrom could not be ignored. He was far too thorough and meticulous, and for 30 years too persistent in the face of his critics, for anyone to refute.”

The LRT has been online for only 8 years, so only 22 to go!

“Though one or two holdouts still resist the idea, it is now widely accepted that birds evolved from the group of bipedal theropod dinosaurs”

“The idea that birds are in fact living dinosaurs is so commonplace that the debate has largely turned to the question of why they were the only dinosaurs to survive the mass extinction of 65 million years ago.”

“More significantly, Ostrom lived to see his ideas about the dinosaur origin of birds—and the feathered plumage of dinosaurs—vindicated by a series of remarkable fossils from northeastern China.”

Those should have been unnecessary as Ostrom explains below.

“On Ostrom’s death in 2005, age 77, the Los Angeles Times wrote that he had “almost single-handedly convinced the scientific community that birds are descended from dinosaurs.” “John Ostrom,” the Sunday Times (London) added, “did more than anyone else to make dinosaurs interesting, real, and visceral.”

“When NPR’s All Things Considered marked the occasion by interviewing Ostrom’s first research student, Bob Bakker, the paleontological world held its breath for a moment, recalling the troubled relationship between these two allies in the dinosaur renaissance. But when asked how important Ostrom had been to dinosaur paleontology, Bakker graciously commented: “Nobody was more important.”

In the comments section to the online article,
you can read from Paul Sereno’s epitaph of Ostrom, “He did more than simply point out the great number of similarities between this theropod and the early bird Archaeopteryx. He argued that these similarities were derived. That is, that they were synapomorphies—shared morphology from common ancestry.”

We looked at Ostrom’s frustration with
the slow pace of paleontology earlier. Here it is again.

According to the Hartford Courant (2000), “In 1973, Ostrom broke from the scientific mainstream by reviving a Victorian-era hypothesis (see above) that his colleagues considered far-fetched: Birds, he said, evolved from dinosaurs. And he spent the rest of his career trying to prove it.” With the announcement of the first dinosaurs with feathers from China, Ostrom (then age 73) was in no mood to celebrate. He is quoted as saying, ““I’ve been saying the same damn thing since 1973, `I said, `Look at Archaeopteryx!’” Ostrom was the first scientist to collect physical evidence for the theory. Ostrom provoked a debate that raged for decades. “At first they said, `Oh John, you’re crazy,”’ Ostrom said in 1999.”

On the night Ostrom was to be honored
at the annual convention of the Society of Vertebrate Paleontology, I noticed him walking alone to the proceedings. I took advantage of the coincidence to walk with him. He was gracious enough to allow that. I cannot remember the substance of our conversation. As soon as we got to the building, he was swept up into the celebration as everyone else wanted their own moment with the man who saved dinosaurs.


References

https://pterosaurheresies.wordpress.com/2016/03/16/sometimes-it-takes-the-paleo-crowd-an-epoch-to-accept-new-data/

https://yalealumnimagazine.com/articles/3921-the-man-who-saved-the-dinosaurs?fbclid=IwAR1HMFU7cxeqn-iGd8dtO6nAxsjpERhyTza2AnpkCDz05k9fY3w-63-q4Wc

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

Ostromia: The Haarlem specimen of Archaeopteryx

Updated January 17, 2018 with a new tracing and nesting of Ostromia as a sister to Eosinopteryx in the proximal outgroup clade to the birds. 

Updated June 23, 2109 with revised closeup images of the pelvis, ‘clavicle’ and pes.

A recent paper
by Foth and Rauhut 2017 reexamined the incomplete Haarlem specimen on plate and counter plate (TM 6928, 6929, Figs. 1–3) originally attributed to a pterosaur (Pterodactylus crassipes, von Meyer 1857) and later to Archaeopteryx crassipes (Ostrom 1970). The co-authors renamed the specimen Ostromia crassipes and nested it with Anchiornis (Fig. 2), a larger troodontid with a short coracoid outside of the bird clade in the large reptile tree (LRT).

Figure 1. The Haarlem specimen of Archaeopteryx now named Ostromia crassipes.

Figure 1. The Haarlem specimen of Archaeopteryx now named Ostromia crassipes.

Foth and Rauhut 2017
considered Anchiornis“the possibly oldest and most basal clade of avialan, here named Anchiornithidae.” And they considered Ostromia the first and only anchiornithid outside of the Tiaojushan Formation of China.

Figure 1. Anchiornis, the pre-bird troodontid, to scale with Ostromia, the Solnhofen bird, the Haarlem specimen.

Figure 1. Anchiornis, the pre-bird troodontid, to scale with Ostromia, the Solnhofen pre-bird, the Haarlem specimen.

The authors employed a previously published phylogenetic analysis
from Foth et al. 2014. which looked at the privately owned 11th specimen of Archaeopteryx. Unfortunately their cladogram lumped all Archaeopteryx specimens (Fig. 3) together. So we’re dealing with a possible taxonomic chimaera and a certain taxon exclusion.

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

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

The variety shown by the Solnhofen birds
(Fig. 3) should invite phylogenetic analysis (Fig. 4). But Foth et al. (2014, 2017) did not respond to the invitation. If they had done so, perhaps they would have replicated the results of the LRT in nesting Ostromia with other coeval Archaeopteryx specimens. Their Ostromia nests here with Eosinopteryx, not with Anchiornis.

In size, strata and morphology
Ostromia nests rather closely to the other Solnhofen birds in the LRT, but in the proximal outgroup, along with Eosinopteryx and Xiaotingia.

I encourage bird workers
to not lump the Solnhofen birds together as a single taxonomic unit, but to split them into individual specimens. There’s a treasure to be found there. Each one deserves to be its own species, if not its own genus.


Revised images in detail

Closeup figure of femora and pubis of Ostromia.

Figure x. Closeup figure of femora and pubis of Ostromia traced on data from both plates. It is still tricky to see the elements. Blue lines could be bones or soft tissue in this fossil.

Figure y. Closeup of possible displace clavicle with alternate curved rib and busted clavicle interpretation.

Figure y. Closeup of possible displace clavicle with alternate curved rib and busted clavicle interpretation.

Figure z. Pedes of Ostromia in greater precision and closeup. It is apparent that digit 2 on both pedes had a robust ungual and phalanges.

Figure z. Pedes of Ostromia in greater precision and closeup. It is apparent that digit 2 on both pedes had a robust ungual and phalanges even accounting for displaced keratin sheaths.


References
Foth C and Rauhut OWM 2017. Re-evaluation of the Haarlem Archaeopteryx and the radiation of maniraptoran theropod dinosaurs. BMC Evolutionary Biology 17:236
Foth C, Tischlinger H, Rauhut OWM 2014. New specimen of Archaeopteryx provides insights into the evolution of pennaceous feathers. Nature 511:79–82.
Ostrom JH 1970. Archaeopteryx: notice of a “new” specimen. Science. 1970;170:537_538.
Von Meyer H 1861. Archaeopteryx lithographica und Pterodactylus. N Jb Min Geognosie Geol Petrefaktenkd. 1861:678–679.

TM = Teylers Museum in Haarlem, the Netherlands

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